Identification and validation of risk factors in cold work

DOCTORA L T H E S I SDOCTORA L T H E S I S

Luleå University of TechnologyDepartment of Human Work Sciences • Division of Industrial Production Environment

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Identification and validation of risk factors in cold work

Lina Giedraitytė

Identification and validation of risk factors in cold work

by

Lina Giedraityt

August, 2005

– Utititi, šalta, – Skundžiasi ruduo: – Kas pasi s man palt ,Kas kepur duos?

Kojos jau sušlapo, Permerk lietus. Kas iš klevo lapo Man pasi s batus?...

Ištrauka iš Justino Marcinkevi iaus„R udens skundas”

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Preface

The work for this Doctoral thesis was carried out at the Division of Industrial Working Environment, Department of Human Work Sciences, Luleå University of Technology. Financial support has been generously provided by Luleå University of Technology, the European Regional Development Fund (Barents Interreg IIA Program) and the Swedish Institute.

The primary tutor has been professor Ingvar Holmér from the Thermal Environment Laboratory, Department of Design Sciences, Lund Technical University with tutor assistance provided by professor Jan Johansson and associate professor Bo Johansson. Professors Houshang Shahnavaz and John Abeysekera not only introduced me to the field of ergonomics, but also encouraged me for the more advanced studies in the field.

I would also like to express my gratitude to research engineers Tanja Risikko and Anita Hicks, educational trainer Liisa Hänninen and trainer Maire Huurre from the Cold Work Action Program of the Finnish Institute of Occupational Health, Oulu, Finland for conducting the studies involving Finnish observers. Director Arvid Påsche and senior engineer Bård Holand from Thelma AS, Trondheim, Norway are also due my thanks for their contributions to the studies with Norwegian observers.

I am also grateful to all co-authors of the articles included in this thesis along with the subjects who made it possible.

I would like to thank all of the employees at the Department of Human Work Sciences for making Arbetsvetenskap a nice place to belong.

Thanks to all my friends scattered all over the world. Special thanks to the ones here in Sweden who shared with me the dark and cold winters.

Finally, my unadulterated gratitude goes to Dr. Andrew Bérubé for being a benevolent native English speaker (for all that it implies to live among non-native speakers), for eloquently putting my research into the perspective of geophysics and for simply being my better half, often a less devilish one.

Nuoširdus d kui keliauja ir Lietuv . Nors ir atsid r s šio ilgo s rašo gale, jis tikrai ne mažiau svarbus, nes skirtas visiems tiems, kurie kiekvien kart nekantriai laukia man s sugr žtan ios – ypa t iui, mamai ir broliui Ar nui. Kas iš man s ir belikt be j s vis ir gimt j namšilumos!

August, 2005Luleå

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Abstract

There are very few methods available for the assessment of cold exposure and they rely more or less on complex equations for calculating heat balance; therefore, there is a need for new practical methods for the identification and control of cold hazards in workplaces.

In the first study, the aim was to test a checklist which enables cold risk assessment based on observations in the workplace. The checklist has seven main sections of cold related risk factors: ‘cold air’, ‘wind/air movements’, ‘contact with cold surfaces’, ‘exposure to water/ liquids/moisture’, ‘protective clothing against cold’, ‘protection of hands/feet/head from cold’ and ‘the use of personal protective equipment’. A total of 82 evaluation sheets were obtained from the field testing (24 from Sweden and 58 from Finland). The subjects found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment procedure, the interference of the method with the observed work, the adequacy of the instructions and the facility of the checklist.

In the second study, the aim was to test a checklist in workplaces in a country representing a different approach to safety culture than the one prevailing in Scandinavian countries. The secondary objective was to test whether there was a learning effect reflected in the results recorded in the evaluation sheets filled in after conducting cold risk assessment procedure for the first, the second and the third time. A total of 277 evaluation sheets were obtained from 116 observers from the two sawmills in north-western Russia. The observers, similarly to the ones in Finland and Sweden, found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment procedure; the instructions provided to the checklist and to the summary table; the facility of the checklist and of the summary table and the suitability of the checklist (in regards to the structure and the content) to identify the cold-related risk factors. According to the Nordic observers, a workers’ representative responsible for industrial safety and workers themselves should carry out the assessment procedure at the workplace. On the contrary, the Russian observers mentioned workers only in 7.5% of the evaluation sheets giving priority to a safety engineer (mentioned in 50.5% of evaluation sheets) and a foreman (mentioned in 22.6% of evaluation sheets). No statistically significant effects of learning were found when three groups of answers (after the first, second and third time) from 73 observers were compared.

In the third study, the objective was to validate the checklist for the identification of cold-related problems under laboratory conditions in terms of whether the checklist generated results were in accordance with the subjects’ physiological measurements and self-reported observations of their thermal state. Eight male subjects were screwing bolts with both gloves and bare hands and stepping in 0°C, walking at 3.5 km/hour and 4.9 km/hour in –10°C and at 3 km/hour in –25°C and standing still at 4°C in the climatic chamber. In conclusion, the number of subjects who assessed the particular cold related risk factor by means of the checklist in conformity to their reported thermal sensations and measured skin temperatures varied most often from five to eight subjects. In some rare cases, only one, two or three subjects gave evaluations that were in agreement. In particular, this was the case for risk factors concerning the presence of light work and protection of extremities against cold, when several work tasks were performed under the same experiment.

In the fourth study, the aim was to identify cold-related risk factors that people face in their work environment and to investigate whether the region where the checklist was filled in, the type of work (indoor versus outdoor work), ambient temperatures and the sector that the company represented had any influence on the ratings that these factors received. Cold-related risk factors were assessed in 14 companies representing various work activities in

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construction, stevedoring and storage, tourism, sawmills, fish processing, forestry and road building industries in four countries: Finland, Norway, Sweden and north-western Russia. An observational checklist for the assessment of 13 cold-related risk factors was applied and 164 checklists were filled in by 80 selected observers in the Nordic countries and 277 checklists were completed by 116 selected observers in north-western Russia. The observers consisted of worksite managers, occupational health and safety (OH&S) representatives, occupational nurses and the workers themselves. The majority of the cold-related risk factors were rated differently by Nordic and Russian observers in term of either the chosen severity of the problem (‘no problem’, ‘slight problem’ or ‘considerable problem’) or the frequencies of ratings along these categories. Five factors (‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’ and ‘highly varying workload’) were most often rated as slightly problematic and two factors (‘protective clothing against cold’ and ‘light work’) as causing no problems by both groups. The remaining six factors (‘protection of extremities against cold’, ‘use of PPE’, ‘long-term cold exposure’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’) were rated differently by Nordic and Russian observers, and the latter indicated less favourable situations at the observed workplaces. Only a few factors had different ratings if various variables (nature of work, ambient temperatures and sector of economic activities) were taken into account.

In the fifth study, the aim was to validate the Edholm scale and the ISO 8996 standard by comparing the metabolic rates estimated for both methods with the actual measured metabolic rate (MMeas) in six manual material handling tasks simulated under laboratory conditions. The metabolic rate was calculated from the oxygen consumption 2OV (19 participants) according to Standard No. ISO 8996. Additionally, the subjects estimated perceived exertion using the Borg scale. The metabolic rates derived from the Edholm scale (MEdh) overestimated five of six activities by 34–50% ( =.05). The metabolic rates derived from ISO 8996 (MISO)overestimated all activities by 7–38% ( =.05).

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List of publications

This thesis is based on the following papers that can be found in the appendix II:

Paper I Giedraityt , L., Mäkinen, T.M., Holmér, I., Hassi, J. (2005). The field testing of an

observational checklist for the assessment of cold-related risk factors. International Journal of Circumpolar Health, manuscript accepted for publication.

Paper II Giedraityt , L., Rybitski P.N., Loukianova, N. (2005). The usability of an observational

checklist for the assessment of cold-related risk factors tested by Russian sawmill workers.Submitted to International Journal of Industrial Ergonomics.

Paper III Giedraityt , L., Holmér, I., Gao C., Kuklane K. (2005). Validation of the observational

checklist for the assessment of cold-related risk factors under laboratory conditions. Submitted to Applied Ergonomics.

Paper IV Giedraityt , L., Mäkinen, T.M., Abeysekera, J., Holmér, I., Hassi, J. (2005). Observed cold-

related risk factors for indoor and outdoor work in the Nordic countries and north-westernRussia. Submitted to International Journal of Industrial Ergonomics.

Paper V Giedraityt , L., Holmér, I., Gavhed, D. (2001). Validation of methods for determination of

metabolic rate in the Edholm scale and ISO 8996. International Journal of Occupational Safety and Ergonomics, 7(2), 135–148.

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Table of contents

1. Introduction ............................................................................................................................ 1 1.1. Occupational exposure to cold ....................................................................................... 1 1.2. Human thermal balance and heat loss ............................................................................ 1 1.3. Effects of cold exposure................................................................................................. 2

1.3.1. Physiological responses to cold.............................................................................. 2 1.3.2. Subjective responses to cold .................................................................................. 3 1.3.3. Performance in cold ............................................................................................... 3 1.3.4. Health effects.......................................................................................................... 4

1.4. Cold risk assessment ...................................................................................................... 51.4.1. Risk assessment in the working life ....................................................................... 5 1.4.2. Cold-related risk factors ......................................................................................... 6 1.4.3. Methods used in cold risk assessment.................................................................... 7 1.4.4. A strategy for cold risk assessment ........................................................................ 8

2. Objectives of the study......................................................................................................... 10 3. Materials and methods ......................................................................................................... 11

3.1. The development of the checklist................................................................................. 11 3.2. Subjects ........................................................................................................................ 12 3.3. Procedure...................................................................................................................... 13

4. Results and discussion.......................................................................................................... 16 4.1. The usability of the checklist ....................................................................................... 16 4.2. The validation of the checklist ..................................................................................... 17 4.3. Risk factors in the cold work........................................................................................ 18 4.4. The validation of the standard...................................................................................... 20

5. Conclusions .......................................................................................................................... 22 6. Possible future investigations............................................................................................... 23 7. References ............................................................................................................................ 24

Appendix I:

A checklist for identifying cold-related problems at work in Finnish: ‘Tarkistuslista kylmän haittatekijöiden tunnistamiseen’

A checklist for identifying cold-related problems at work in Norwegian: ‘Sjekkliste for bedømmelse av kuldeproblemer’

A checklist for identifying cold-related problems at work in Russian: ‘ , ’

A checklist for identifying cold-related problems at work in Swedish: ‘Checklista för att bedöma problem med kyla’

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Appendix I (continued):

A questionnaire used in the study presented in the Paper I:‘Evaluation of the usability of the checklist’

A questionnaire used in the study presented in the Paper II: ‘Evaluation of the checklist’

Appendix II:

Paper I: The field testing of an observational checklist for the assessment of cold-related risk factors.

Paper II: The usability of an observational checklist for the assessment of cold-related risk factors tested by Russian sawmill workers.

Paper III: Validation of the observational checklist for the assessment of cold-related risk factors under laboratory conditions.

Paper IV: Observed cold-related risk factors for indoor and outdoor work in the Nordic countries and north-western Russia.

Paper V: Validation of methods for determination of metabolic rate in the Edholm scale and ISO 8996.

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1. Introduction

1.1. Occupational exposure to cold Many persons engaged in different occupations face cold exposure of varying duration and intensity. In Sweden, for example, 16.4 % of all employed people (about 4.2 million) in 2001 were exposed to cold work outdoors during winter months or a cold indoor climate for at least a quarter of their working time. If the statistics are divided by gender, 22.7% of all employed men and 9.5% of all employed women were exposed to cold environment at their workplaces for at least a quarter of their working time (Statistics Sweden, 2002). The percentages are somewhat higher than those of 1999, when 14.8 % of all employed persons (or 21.5% of men and 7.3 % of women) faced such working conditions (Statistics Sweden, 2000).

In Sweden, the occupational groups (according to the Swedish Standard Classification of Occupations, SSYK) most exposed to cold, are: skilled agricultural and fishery workers (60.6% of employed persons in this group are exposed to cold at least a quarter of the time); craft and related trades workers (38.4%), especially subgroups such as building frame and related trades workers (67.0%) and building finishers and related trades workers (45.5%) falling under this category; and plant and machine operators and assemblers (29.1%), especially the subgroups of motor-vehicle drivers (53.4%) and agricultural and other mobile-plant operators (49.8%). In the remaining occupational groups the percentages of exposed workers vary from 2.0 to 25.2%, with certain subgroups having very high percentages such as child-care workers (40.6%), teaching associate professionals (30.5%) and stock clerks and storekeepers (29.0%) (Statistics Sweden, 2002).

In Finland, the weekly duration of exposure to cold at work was reported to be the largest (slightly over 20 hours) among construction workers, assemblers and repairers; higher than average (13 hours) exposure time was reported in farming, military and processing occupations (Hassi et al., 1998).

In the Nordic countries several questionnaire surveys have been carried out in which experience concerning the physical hazards of workplaces have been investigated. In these studies, it was found that 17–28 % of the employees experience draughts and 14–16 % experience coldness as a hazard in their work (Pekkarinen, 1994).

In 2001 in Sweden 0.7% of all employed men and 0.5% of all employed women had work related disorders during the previous twelve months (the time of the survey being a starting point) due to heat, cold or draught (Statistics Sweden, 2005). The percentage was somewhat higher (1.2–2.0%) for the subgroups with the highest share of exposed persons.

1.2. Human thermal balance and heat loss The body generates heat continuously by converting food to energy and using the energy in the form of work. The majority of energy is converted to heat, which contributes to maintaining the body temperature. There must be an appropriate balance between the heat generated and the heat lost/gained from the environment. Whenever a temperature difference occurs between the body and its surroundings, heat transfer processes will occur to reduce this difference. The processes available, depending on the prevailing physical circumstances are heat loss or gain to a solid surface in contact with the body by conduction, heat loss or gain by convection and radiation due to cooler/warmer air and surroundings, and heat loss from the skin and respiratory tract due to evaporation of moisture (Youle, 1995).

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In cold weather, the only source of heat gain is the body’s own internal heat production, which increases with physical activity (Canadian Centre for Occupational Health and Safety, 1995). Hot drinks and food are also a source of heat.

The body loses heat to its surroundings in several different ways. Approximately 60% of heat loss occurs in the form of infrared heat rays or radiation (Herington & Morse, 1995). Conduction accounts for only 2–3 % of the heat loss, although it may increase fivefold in wet clothing and 25-fold in cold water (Herington & Morse, 1995). In general, the higher the temperature difference between the body surface and cold objects, the faster the heat loss by conduction. Convection, or the movement of air currents, produces an average heat loss of 12%, although this amount can greatly increase with wind speed as the rate of loss depends on the air speed and the temperature difference between the skin and the surrounding air (Herington & Morse, 1995). Sweat production and its evaporation from the skin is also a cause of heat loss. This is important when performing hard work. Of the total heat loss of man, at least 20% is usually by evaporation of moisture, both from the skin surface (about two-thirds) and from the respiratory tract through evaporation of water from the lungs (about one-third) (Burton & Edholm, 1969). Small amounts of heat are lost when cold food and drink are consumed. Additional heat is lost during breathing by inhaling cold air.

1.3. Effects of cold exposure Holmér (1994) has summarised the problems associated with occupational cold exposure: thermal discomfort and pain sensation, in particular from the extremities; performance decrements due to cold hands, cold muscles or general cooling or due to hinders caused by protective clothing against cold such as weight, bulk, friction, etc; effects on human health such as cold injuries, initiation and aggravation of symptoms for cardio-respiratory diseases or elevated accident risks; and special requirements that arise from the above named factors for design and performance of work, for planning and design of workplaces and for design and use of equipment and tools.

Ramsey et al. (1983) found that ambient temperature had a statistically significant effect on the so called unsafe behaviour index (UBI). According to the authors, this relationship forms a U-shaped curve, with minimum UBI values occurring in the preferred temperature zone of 17 to 23ºC wet bulb globe temperature (WBGT). If the ambient temperature increases above or decreases below the preferred range, the proportion of unsafe behaviour increases.

1.3.1. Physiological responses to cold Humans are warm-blooded animals; the body core temperature must normally be regulated to remain within a narrow range, typically 37.0±0.5°C, and the usual maximum deviation that can be tolerated by fit people (but with potential strain) is approximately ±2°C (Youle, 1995).

The hypothalamus, a part of the brain, has the main responsibility for body temperature in humans (Parsons, 1993). The hypothalamus accepts the information concerning the temperature status of the body, compares that information with a ‘set point’, and, if needed, initiates the body’s two main defences against cold, shivering and peripheral vasoconstriction (Evenson, 1994). Shivering, produced by involuntary muscle contraction, is the typical response to cold that cause an increase in the metabolic rate and hence the heat production of the body (Peterson, 1991). When the skin cools, blood flow is shunted from vessels which lie near to the surface to those deeper within the tissue, where heat is more easily conserved. This is done by reducing the diameter of the surface capillaries (vasoconstriction) through muscular action (Peterson, 1991). With continued cold exposure, cold-induced vasodilatation (an increase in the diameter of the deeper vessels) alternates with peripheral vasoconstriction

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to conserve core heat and, at the same time, intermittently save function in the extremities (Evenson, 1994). Cold stress can quickly overwhelm human thermoregulation with consequences ranging from impaired performance to death (Stocks et al., 2004).

1.3.2. Subjective responses to cold Thermal sensation (discomfort and pain sensation) is related to how people feel and is therefore a sensory experience and a psychological phenomenon, thus it is not possible to define sensation in physical or physiological terms (Parsons, 1993). For example, cooling of the hand is very individually perceived (Hammarskjöld, Harms-Ringdahl & Ekholm, 1992). However, most people feel comfortable when the air temperature ranges from 18°C to 22°C and the relative humidity is about 45% (Pathak & Charron, 1987).

Nerves in the skin can detect the sensation of cold as the nerves endings, some of which respond to warm stimuli and some to cold, are distributed across the skin (Evenson, 1994). There are apparent anomalies whereby the skin can feel ‘cool’ at a temperature greater than that where the skin feels ‘warm’, because of the previous adapting temperature and rate of temperature exchange. This phenomenon is valid for small areas of the skin and also to the whole body sensation (Parsons, 1993).

Pain due to cold is related to vasoconstriction of blood vessels, but at low temperatures however, cold induced vasodilatation increases blood flow with an associated pleasant sensation (Parsons, 1993).

Although pain due to cold can be very intense, the physiological correlations are not so clear (Parsons, 1993). Havenith, Van de Linde & Heus (1992) have studied thermal and pain sensation associated with hand cooling in 12 subjects while they touched six different materials. They found that equal pain and thermal levels were associated with lower temperatures for the back of the hand than for the contact side: the slightly painful condition was associated with a skin temperature of 16oC for the back and 19oC for the palm of the hand. They have also reported that pain level appeared to be inversely related to cooling speed (Havenith, Van de Linde & Heus, 1992). However, another study (Chen, Nilsson & Holmér, 1994) investigating skin temperature changes and the subjective sensations of bare fingers touching a cold aluminium surface (in 25 subjects) reported that thermal and pain sensation lacked a good correlation with temperatures and temperature changes. Furthermore, it was found that both thermal and pain sensation strongly correlated to the skin temperatures on the hand and fingers under convective cooling, while no correlation was found under contact cooling (Chen & Holmér, 1998). Subjective judgements such as the decrease in finger pain and cold sensation during repeated finger cooling and the absence of them during post-immersion rest may not be reliable indicators for monitoring the risk of progressive tissue cooling and frostbite formation (Sawada, Araki & Yokoyama, 2000).

When feet were cooled, cold and pain sensations were connected with considerably lower temperatures in toes and heels (Kuklane, Geng & Holmér, 1998).

It has been reported that subjects immersed in cold water (+10oC) were unable to reliably assess how cold they were (Hoffman & Pozos, 1989). The authors came to the conclusion that subjects who are rapidly cooled in water may have considerable difficulty separating feelings of cold from feelings of pain and discomfort.

1.3.3. Performance in cold Cold exposure and the associated behavioural and physiological reactions have an impact on human performance, i.e. manual, muscular and aerobic performance, simple and choice

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reaction time, tracking, vigilance, cognitive tasks, etc (Holmér, Granberg & Dahlström, 1998). In a study of forklift workers who were entering cold stores very frequently for short periods of time, the reported cold stress and the decrease in workers' performance were the same as for continuous exposure to cold (Tochihara, 2005).

Manual performance is a combination of many kinds of ability that require, for instance, good tactile sensitivity, hand dexterity, force capability and motor co-ordination, and these skills are all influenced by hand cooling (Geng, Karlsson & Holmér, 2000). During cold exposure, manual performance is affected negatively and a significant increase in rapid erroneous responses is demonstrated (Enander, 1986). Various aspects of the effects of hand cooling on manual performance were investigated by many authors (Hammarskjöld, Harms-Ringdahl & Ekholm, 1992; Giesbrecht, Wu, White, Johnston & Bristow, 1995; Tochihara, Ohnaka, Tuzuki & Nagai, 1995; Tochihara, Ohkubo, Uchiyama & Komine, 1995; Ozaki, Nagai & Tochihara, 2001; Cheung, Montie, White, & Behm, 2003; Nowak, & Hermsdorfer, 2003; Jay & Havenith, 2004).

Cold impairs the performance of complex mental tasks, while relatively simple tasks are unaffected (Enander, 1987; Thomas, Ahlers, House & Schrot, 1989; Giesbrecht, Arnett, Vela & Bristow, 1993).

Cooling negatively affects all components of muscular performance: endurance, force, power, velocity and co-ordination (Oksa, Rintamäki & Mäkinen, 1991; Oksa, Rintamäki & Mäkinen, 1992; Oksa, Rintamäki & Mäkinen, 1993; Howard, Kraemer, Stanley, Armstrong & Maresh, 1994; Oksa, Rintamäki & Rissanen, 1997; Oksa, 2000.).

1.3.4. Health effects Cold injuries occur as the result of man’s inability to properly protect himself from cold with subsequent lowering of the core body temperature (Holmér, Granberg & Dahlström, 1998). Injuries from cold exposure are divided into two major types: non-freezing cold injuries (hypothermia, chilblains and trench/immersion foot) and freezing cold injuries (frostnip and frostbite).

Hypothermia, the lowering of core body temperature below 35°C, occurs when the body is unable to produce enough heat to replace heat lost to the environment (Evenson, 1994). As the core temperature continues to fall, the heart rate slows, breathing shallows, shivering diminishes and consciousness is lost at 32°C to 30°C (Wilkerson, 1986). The lowest known temperature for therapeutic survival of hypothermia is 9°C (Herington & Morse, 1995). Chilblains is cold injury from repeated exposure of bare skin to wet, windy conditions at temperatures ranging from 15°C to near freezing and although uncomfortable, it causes little or no impairment (Wilkerson, 1986). Trench/immersion foot develops slowly over a period of hours to days from prolonged exposure of the lower extremities to cold (0°C to 10°C) and moisture (Burtan, 1994).

Frostbite, damage to tissue caused by overexposure to low temperatures usually involving the toes, nose, ears or fingers can cause injury ranging in severity from quite superficial but painful to frank necrosis (Peterson, 1991). Frostnip is a mild, reversible, superficial injury that involves no loss of tissue (Evenson, 1994).

Circulatory changes due to cold include a rise in cardiac output, an increased blood pressure and a higher peripheral vasoconstriction (Burton & Edholm, 1969). Cooling of the forehead and head elicits an acute elevation of systolic blood pressure and, eventually, elevated heart rate, however this reaction is of short duration and normal or slightly elevated values are regained after seconds or minutes (Holmér, Granberg & Dahlström, 1998).

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There is little evidence of cold injury of the respiratory tract due to cold (Parsons, 1993). Inhalation of moderate volumes of cold dry air presents limited problems in healthy persons (Holmér, Granberg & Dahlström, 1998).

Snow, ice and reduced visibility increase the incidence of accidents in the cold. Snow blindness and sunburn may occur when the skin and eyes are unprotected from the ultraviolet rays of the sun and their reflection off the snow. The use of heaters and stoves increases the risk of fire, burns and carbon monoxide poisoning, particularly in confined spaces (Evenson, 1994).

The sensitivity and dexterity of fingers lessen in cold. At lower temperatures, cold effects deeper muscles, resulting in reduced muscular strength and stiffened joints. Mental alertness is reduced due to cold-related discomfort. For all these reasons accidents are more likely to occur in very cold working conditions (Pathak & Charron, 1987).

The use of protective clothing against cold is sometimes compromised, even when this has detrimental effects on one’s health. Manual tasks in cold are often done with bare hands or wearing thin gloves (Risikko & Anttonen, 1998), as the use of thick protective gloves against cold can impair manual functions such as hand dexterity or precision. Protective clothing against cold cannot always provide a satisfactory level of protection. For example, cold feet was one of the biggest sources of complaints for Swedish farmers regarding their thermal work environment (Kuklane, 2000). Although a hood is superior in comparison to other possibilities for protecting the face such as a face mask or a scarf (Rintamäki, Mäkinen & Gavhed, 1998), the problem of combining it with a safety helmet is still unsolved. Personal protective devices used in cold climate can become clumsy and uncomfortable, and therefore prevent the worker from wearing them (Berquist & Abeysekera, 1994).

1.4. Cold risk assessment

1.4.1. Risk assessment in the working life The employer has a duty to ensure the safety and health of workers in every aspect related to the work, and the employer shall, among other things, be in possession of an assessment of the risks to safety and health at work (Council of the European Communities, 1989).

In Sweden, all employers ‘shall regularly investigate working conditions and assess the risks of any person being affected by ill-health or accidents at work’ (Arbetsmiljöverket, 2001). In Sweden, according to these provisions, the risk assessment should be documented in writing indicating which risks are present and whether or not they are serious.

The British Standard (1996) is intended to assist organisations in developing an approach to the management of occupational health services (OH&S) in such a way as to protect employees and others whose health and safety may be affected by the organisation’s activities. It promotes the adoption of a structured approach for the identification of hazards and the evaluation and control of work related risks.

According to the standard BS 8800 (1996), for many years OH&S risk assessments have usually been carried out on an informal basis. However, it is now recognised that risk assessments are a key foundation for pro-active OH&S management and that systematic procedures are necessary to ensure their success.

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Figure 1. The process of risk assessment (adapted from BS 8800, 1996)

The standard (BS 8800, 1996) recommends for organisations to follow these basic steps for effective risk assessment (see figure 1):

a) to classify work activities, i.e. to prepare a list of work activities and gather information about them;

b) to identify all significant hazards relating to each work activity, considering who might be harmed and how;

c) to determine risk by making a subjective estimate of the risk associated with each hazard, assuming that planned or existing controls are in place;

d) to decide if the risk is tolerable by judging whether planned or existing OH&S precautions (if any) are sufficient to keep the hazard under control;

e) to prepare a risk control action plan (if necessary) to deal with any issues found by the assessment; and

f) to review the adequacy of the action plan, i.e. to re-assess the risks on the basis of the revised controls and check that they will be tolerable.

1.4.2. Cold-related risk factors Holmér (1998) outlined the relationship between the environmental factors (i.e. air temperature, radiant temperature, humidity and air velocity together with activity and clothing) and the anticipated cooling effects: whole body cooling, local cooling such as extremity cooling, airway cooling (or cooling of respiratory tract), wind chill (or convective skin cooling) and contact cooling (or conductive skin cooling).

Evaluation of the above named types of cold stress requires different sets of measurements (Holmér, 1994), as shown in the figure 2. However, quick estimates (for the purposes of the first rough classification of problems and/or the basis for further action, e.g., for a more detailed assessment or a preventive measure) may be based on the information about the type and intensity of work, air temperature, wind speed and available personal protection (Holmér, 1994).

Classify work activities

Identify hazards

Determine risks

Decide if risk is tolerable

Prepare risk control action plan (if necessary)

Review adequacy of action plan

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Figure 2. Scheme for the identification of cold stress and for the selection of appropriate measurements for its assessment (adapted from Holmér, 1994).

1.4.3. Methods used in cold risk assessment Methods for the assessment of cold stress may serve several purposes and they may be used to evaluate or predict conditions critical to: survival; risk of acute or chronic adverse health effects; performance; efficiency and productivity; and maintenance of comfort (Holmér, 1993). Occupational exposure to cold generally includes conditions associated with minimal adverse health effects.

The thermal environment can be assessed in either subjective terms or by objective measurements, or both. In the former case individuals are asked to give an opinion on the thermal environment which they are experiencing (Youle, 1995). The methods for the assessment of cold stress based on measurements are presented in ISO technical report 11079 (1993). The complementary information needed for the evaluation of cold stress can be found in other standards: ISO 8996 (1990) regarding determination of metabolic heat production; ISO 9886 (1992) regarding evaluation of thermal strain by physiological measurements; and ISO 9920 (1995) regarding estimation of the thermal insulation and evaporative resistance of a clothing ensemble.

The risk for whole body cooling is determined by calculating the clothing insulation level required to maintain the heat balance at defined levels of physiological strain. The calculated required clothing insulation value, IREQ, which indicates a protection level can be regarded as a cold stress index (ISO/TR 11079, 1993). Assessment of contact cooling, extremity cooling and airway cooling is based on empirical or predicted values (Holmér, 1998). For example, ISO/TR 11079 (1993) recommends that local cooling caused by convection, radiation or contact heat losses should not result in hand skin temperatures below 15°C and 24°C for high and low stress levels respectively. At temperatures below –40°C, respiratory and eye protection can be required, particularly with high activity levels and strong wind (ISO/TR 11079, 1993). The workers should not have bare hand contact with cold surfaces below –7°C in order to prevent contact frostbite, and they should protect the hands with

Whole body cooling

Extremity cooling

Skin (convective) cooling

Skin (conducive) cooling

Respiratory cooling

Type of cold stress Air temperature Mean radiant temperature Air velocity Relative humidity Activity level (Clothing)

Air temperature Air velocity



Measurements

Analysis

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mittens if the air temperature is –17.5°C or less (ACGIH, 1989). A method for the assessment of cooling of unprotected skin is called the wind chill index (WCI) which is the chilling temperature that defines the ambient temperature under which calm conditions would produce the same cooling effect as the actual environmental conditions (ISO/TR 11079, 1993).

Holmér (1999) has suggested an approach (see figure 3) that might be used as a framework for the assessment of the possible effects of exposure to cold based on the international standards and other scientific literature available in the field.

Figure 3. Relation between climate, stress, strain and risk assessment (adapted from Holmér, 1999).

1.4.4. A strategy for cold risk assessment The action model (see figure 4) suggested by Risikko et al. (2003) helps to assess and manage the cold-induced health and safety risks at work. The methods available for the assessment of cold exposure are very few and rely more or less on complex equations for calculating heat balance (Holmér, 1991). Therefore a certain level of expertise is needed for successful application of these procedures that might not be available to OH&S people especially in small and medium-sized enterprises (SMEs).

Malchaire, Gebhardt and Piette (1999) addressed this problem and proposed a strategy for the evaluation and prevention of risk due to work in thermal environments, which rests on two basic principles: it is participative and structured in four stages - ‘Screening’, ‘Observation’, ‘Analysis’ and ‘Expertise’ - that require complementary knowledge and competence. According to this strategy, after the screening of the workplace, the second stage ‘Observation’ should provide a method for identifying particular circumstances, specific tasks or certain working conditions where problems related to work in cold exist and guidelines for the elimination of the problem. At the end of this stage the decision has to be made whether the problem is satisfactory controlled; and if not, the third stage ‘Analysis’ of the risk assessment has to be carried out with the help of occupational hygienists or persons with

Air temperature WindHumidity Radiation

ActivityClothing

Precipitation Work organisation

Whole body cooling Extremity cooling Skin convective cooling Skin contact cooling Respiratory cooling

Discomfort Pain

Cold Injury

Cardiac Peripheral circulation Respiration

Muscular function and performance

Individual factors Gender AgeHealth Fitness Acclimatisation

Training Experience Judgement

Cold climate Cold stress Strain/ effect

Stress prediction ‘normal’ response



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adequate training. If the problem still persists the fourth stage ‘Expertise’ has to be addressed ( Malchaire, Gebhardt & Piette, 1999).

The above named methods for cold risk assessment are mostly intended for the stages ‘Analysis’ or ‘Expertise’ due to their complexity and the specific training required. A recent field study (Mäkinen & Hassi, 2002) testing the usability of ISO thermal standards reported that the methods described in these standards were mostly useful in the more advanced stages of cold risk assessment. Furthermore, concerning the assessment of cold environments there are no instructions for how to use the present ISO thermal standards in a complementary way in practical workplace assessments. It was concluded (Mäkinen & Hassi, 2002) that there is a clear need for new practical methods to identify and control cold hazards in workplaces which could be used in the ‘Observation’ stage.

Figure 4. Cold risk management model for a company (adapted from Risikko et al., 2003).

Company’s policies and management systems Occupational health & safety (OH&S)

LEGISLATION & REGULATIONS international & national general labour safety legislation & norms industry-specific safety regulations occupational health care legislation & regulations trade agreements etc.

COLD RISK MANAGEMENT AT WORKPLACE Cold risk assessment

Preventive measures against cold

Supportive information

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2. Objectives of the study

The aims of the thesis were:

(a) to test the usability of the developed observational checklist for cold risk assessment for use in the ‘Observation’ stage by workers themselves or by those responsible for work organisation who usually lack training in ergonomics or human factors.

(b) to test the checklist at workplaces in a country representing a different approach to safety culture than the one prevailing in Scandinavian countries.

(c) to test whether there was a learning effect reflected in the results recorded in the evaluation sheets when filled in after conducting the cold risk assessment procedure for the first, second and third time.

(d) to validate the checklist for the identification of cold-related problems under laboratory conditions in terms of whether the checklist generated results were in agreement with the subjects’ physiological measurements and self-reported observations of their thermal state.

(e) to identify cold-related risk factors that some workers face in their work environment.

(f) to investigate whether the region where the checklist was filled in, type of work (indoor versus outdoor work), ambient temperatures and the sector that the company represented had any influence on the ratings that these factors received.

(g) to validate the Edholm scale and the ISO 8996 standard by comparing the metabolic rates estimated for both methods with the actual measured metabolic rate (MMeas) in six manual material handling tasks simulated under laboratory conditions.

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3. Materials and methods

3.1. The development of the checklist The checklist (see annex 1 of the Paper I) was developed in a common effort by Finnish and Swedish research teams. It followed the recommendations for the ‘Observation’ method based on the results of validations carried out by 42 trained people in occupational health who worked primarily in SMEs and were confronted with climatic problems (Malchaire, Gebhardt & Piette, 1999). According to these guidelines, a checklist should be designed for use by people in industry (preferably by the workers themselves). It should be easy to understand even by untrained people (no references to concepts or technical terms), easy to use (the maximum required time no longer than one hour), based on simple observations (no measurements involved), oriented towards prevention and utilising the user’s knowledge of the workplace (Malchaire, Gebhardt & Piette, 1999).

The relationship between climatic factors, i.e., low surface temperature, low air temperature and wind, and the anticipated cooling effects, i.e., whole body cooling and local cooling such as extremity cooling, airway cooling (or cooling of the respiratory tract), wind chill (or convective skin cooling) and contact cooling (or conductive skin cooling) is well known (Holmér, 1998). Although the evaluation of the above named types of cold stress requires different sets of measurements, a quick estimate (for the purposes of the first rough classification of problems and/or the basis for further action, e.g., for a more detailed assessment or a preventive measure) may be based on information about the type and intensity of work, air temperature, wind speed and available personal protection (Holmér, 1994).

The developed checklist has seven main sections of cold-related risk factors: cold air, wind/air movements, contact with cold surfaces, exposure to water/liquids/moisture, protective clothing against cold, protection against cold: hands, feet and head and the use of personal protective equipment. Each of these seven sections has a choice of three levels (or ratings) for the risk factor and each level contains examples, facilitating the rating process. The following rating scale was applied: score 1 means that there is no need for preventive actions, score 2 indicates that corrective actions are recommended in the long term and score 3 denotes immediate need for corrective action. The same rating scale, although without examples for each level, applies to section 8 ‘Other problems related to work in cold’ that includes: long periods of time in cold, light work, variation between light and heavy work, variation of environmental conditions, slipperiness and insufficient lighting.

An important risk factor, low activity level or rate of work was not included in the seven main sections while two other categories, ‘Light work’ and ‘Variation between light and heavy work’ were added under section 8 instead. The likelihood of the appearance of one or more defined cold problems is very dependent on the combination of two variables: the temperature and the activity level (Holmér, 1998), which makes it difficult to interpret. For example, to rate light work at the very risky activity level would not be right for temperatures above zero, whereas it would be true for low temperatures.

The checklist is accompanied by instructions on how and when to use the checklist and a summary table that helps to interpret the results. The instructions attached to the summary table give a more detailed explanation of the scoring scale. Besides the score columns, the table has a column ‘A further investigation needed’ that has to be marked when the problem cannot be solved at this stage of risk assessment procedure and the third stage ‘Analysis’ has

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to be addressed. The other column ‘Preventive measures’ in the summary table is reserved for choosing the appropriate preventive measures.

3.2. SubjectsStudy I In Finland, four foremen filled in a checklist and a checklist evaluation sheet 31 times, three occupational nurses did it nine times and seven workers carried out the procedure 18 times. In the cases of the foremen and occupational nurses (except for the two nurses at the electrical installations company), the same person evaluated several working activities at the workplace on a single occasion using separate checklists and evaluation sheets for each observed activity. Therefore, the total number of the returned checklists and evaluation sheets is higher than the total number of the persons multiplied by the checklist testing occasions.

In Sweden, the checklist was tested at two construction companies, a road building company and a district office of the National Board of Forestry in the Northern part of Sweden. Both the workers (13) and the foremen (5) in these companies tested the risk assessment procedure.

Study II The cold-related risk factors were observed 277 times at two sawmills by nine foremen (27 checklists were filled in) and 105 workers (250 checklists). Only the workers that were currently working outdoors on the day when the authors visited the two sawmills for the first and second time were asked to volunteer for the study. In the original study design it was intended that all observers should conduct the risk assessment procedure three times; therefore it was not possible for additional workers to join the study on a later occasion. However, some of the observers dropped out and only 88 of 116 volunteers filled in the checklist twice and only 73 of them did it three times.

Study III Eight healthy non-smoking male subjects volunteered to participate in the experiment. The subjects were of 22–38 years of age (mean=28, SD=5), 53.0–87.6 kg of weight (mean=71.6, SD=11.1) and of 1.70–1.89 m of height (mean=1.81, SD=0.06). The subjects’ body surface area according to Du Bois ranged from 1.60 to 2.14 m2 (mean=1.91, SD=0.07). The subjects had the following occupations: a warehouseman (1), a medical doctor (1), a student (5), and a university lecturer (1). None of the subjects could be characterised as working in cold environments. However, all of them had a previous experience of cold exposures to temperatures at least as low as –20°C.

Study IV Cold-related risk factors were assessed at 14 companies in four countries: Finland, Norway, Sweden (during December 2000 – April 2001) and north-western Russia (during December 2003 – March 2004). An observational checklist for the assessment of cold-related risk factors was used by 196 selected observers. A total of 164 checklists were filled in the Nordic countries and 277 checklists were filled in north-western Russia (Archangelsk region).

In Finland, four foremen, three occupational nurses and seven workers observed cold-related risk factors at two construction companies (29 checklists filled in), two stevedoring and cargo handling companies (28 checklists), the skiing and arctic golf centre (6 checklists) and a small company providing electrical installation services (9 checklists). There were 72 checklists in total returned by Finnish observers. In Norway, the cold-related risk factors were observed 48 times at two fish processing companies by an occupational health and safety representative

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(1) and workers (47). In Russia, the cold-related risk factors were observed 277 times at two sawmills by nine foremen (27 checklists were filled in) and 105 workers (250 checklists). In Sweden, a total of 44 checklists were filled in at two construction companies (21 checklists), a road building company (4 checklists) and a district office of the National Board of Forestry in the Northern part of Sweden (19 checklists). Both the workers (13) and foremen (5) at these companies observed the cold-related risk factors.

Study V Nineteen (14 males, 5 females) healthy subjects volunteered to take part in the experiment. Before the experiment, the subjects were informed on all details of the experimental procedures and the associated risks and discomforts. The subjects’ mean age was 29.0 years, SD was 5.4 years, average body mass was 69.2 kg, SD was 12.7 kg, average height was 1.72 m, SD was 0.09 m and average estimated body surface (area Dubois) was 1.81 m2, SD was 0.17 m2. The subjects were asked to abstain from strenuous physical activity on the morning of the measurement in order to minimise residual effects of activity on the metabolic rate measurements.

3.3. ProcedureStudy I The study was carried out in the northern part of Finland and Sweden during December 2000 and April 2001. All the materials were prepared in English and later were translated into Finnish and Swedish. The training and testing of the checklists were conducted identically in each country.

The purpose of the study was explained to subjects who tested the usability of the checklist. After this the authors of the article together with the observer went through the instructions, the cold risk assessment checklist, the analysis table and the evaluation sheet (see appendix I). The observers were asked to perform the cold risk assessment procedure and to fill in the evaluation sheet for the checklist usability independently of the previous times, if any were already carried out. The subjects were also specifically asked to use a separate checklist evaluation sheet after each checklist was filled in. The observers themselves chose the time for conducting the risk assessment procedure. The assessment procedure was performed various times per subject.

Study II The study was carried out in the region of Archangelsk, north-western Russia, from December 2003 until March 2004. The purpose of the study was explained to observers who tested the usability of the above named checklist. After this the authors of the article together with the observers went through the instructions, the cold risk assessment checklist, the analysis table and the evaluation sheet (see appendix I). The one-page checklist evaluation sheet was attached to the checklist.

Study III Tests were carried out during the winter season (January–February, 2005). Each subject performed each of the six activities during the same period of the day with intervals of at least one day in between the experiments.

All clothes worn by the subjects during the particular activity (see table 1 in Paper I), skin temperature measurement sensors and heart rate measuring device were weighed several times during the experiment. The sensors were taped on the subjects’ skin with adhesive tape covering the thermistors.

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The subjects were performing activities A, B, C, D and E for 90 minutes and activity F for 60 minutes (see table 1 in Paper I). During activities B, C, D and E the subjects walked on a treadmill and during activity F they were standing still. In the beginning of activity A, the subjects were sitting and screwing metal bolts with bare hands (activity A1). After 20–30 minutes (depending on the subjective assessment of the subjects whether it was appropriate to continue until the estimated time of 30 minutes had elapsed), the stepping test (activity A2) was performed for 20–25 minutes, depending on the physical fitness of the subjects. At the end of activity A, the subjects were screwing the bolts again, but this time the bolts were wet and the subjects were wearing gloves (activity A3).

Exhaled air was collected with Douglas bags and the average value was used as a representative value for the whole activity. The ambient air (for O2 and CO2 concentrations) in the climatic chamber was sampled and analysed for periods when exhaled air was collected. The metabolic rate ( M ) for each activity was determined based on the measured

2OV (ISO 8996, 1990).

The rectal temperature was measured to represent the body core temperature ( coreT ). The mean skin temperature ( skinT ), was calculated from the temperatures measured by the thermistors positioned on the subjects’ forehead, left scapula, left chest, left upper arm, left forearm, left dorsal hand, left anterior thigh and left calf. In order to measure finger skin temperatures thermistors were placed on the first phalanxes of the left little finger ( fingerlitleT _ )and the right index finger ( fingerindexT _ ). Toe skin temperatures were derived from thermistors placed on the dorsal first phalanx of the left second toe ( toeT ) and facial temperature was obtained from a thermistor placed on the left cheek ( cheekT ). The latter four temperatures were used as a control (during the experiment) and reference temperatures for recorded subjective thermal sensations. Mean body temperature ( bodyT ) was calculated as a sum of mean skin

temperature, skinT , (with coefficient 0.2) and body core temperature, coreT , (with coefficient 0.8). The body heat storage ( S ) was calculated as a function of the rate of change in mean body temperature bodyT .

The subjects’ perceived observations of the thermal sensation of the body, face, hands and feet were recorded using a scale from +4 (very hot) to –4 (very cold). Along with thermal sensations, the subjective judgments on thermal comfort/discomfort on a scale from 0 (comfortable) to 4 (very uncomfortable) and thermal preference on a scale from +3 (much warmer) to –3 (much cooler) were recorded as well. Pain sensations in the feet, hands and face were recorded on a scale from 0 (no pain) to 4 (very very painful). These subjective judgments on the subjects’ thermal state and sensations were recorded immediately upon entering the climatic chamber and at each 10th minute during the performed activity.

The subjects filled in the checklist for identifying cold-related problems at work after the experiment was finished and they had changed back into their own clothes.

Study IV An observational checklist for the assessment of cold-related risk factors was used to assess cold-related risk factors. The authors provided identical instructions and training on how to carry out the cold risk assessment procedure to the observers in all four countries and prepared the needed material including the checklist itself in each country’s national language. Each observer was asked to perform the cold risk assessment procedure and to fill

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in the checklist independently of the previous times, if any were already carried out. The assessment procedure was performed various times per observer.

Study V The study was limited to involve activities of low and moderate metabolic rate. Six manual material handling tasks occurring in normal work were designed under laboratory conditions (see table 1 of Paper V). A metabolic rate value (MEdh) for each of the activities was derived from the Edholm scale (Edholm, 1966) as well as MISO from ISO 8996 (1990) tables. The subjects performed the tasks in a random sequence.

The oxygen consumption ( 2OV ) was measured every ten seconds continuously under the whole time of experiment without subjects taking off the facemask. The morning resting metabolic rate (MRest) at normal room temperature was measured to obtain a reference point in the study before measuring metabolic rates, when subjects were performing various tasks.

Each subject was assigned randomly one task after another till all six simulated tasks were performed. Additionally subjective estimates of exertion were obtained using the RPE scale (Borg, 1970). Before the experiment began, the subjects were instructed how to rate the degree of exertion. They were asked to rate it as accurately and naively as possible. After the particular activity was finished, the scale was shown to a subject immediately and the subject was asked to mark a number on the scale according to how the work was experienced.

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4. Results and discussion

4.1. The usability of the checklist The results of testing the observational checklist showed that it complies well with the recommendations given by Malchaire, Gebhardt & Piette (1999) for the ‘Observation’ method. According to the field testing results, the developed checklist is an observational method that does not require comprehensive training or knowledge in the assessment of thermal environments, and it causes no interference with the observed work activities. The majority of the observers could easily conduct the risk assessment procedure according to the instructions they had received and found it easy to use the observational checklist. Although there was a difference in the experienced checklist facility between the Finnish and Swedish groups, the majority of the evaluation sheets in each of group indicated that it was easy to use the checklist.

Furthermore, the persons who should be performing the cold risk assessments, as suggested by the observers, are the ones who are very well versed in the content of the work. According to the Finnish observers, a workers’ representative responsible for industrial safety and workers themselves should carry out the assessment procedure. This approach was supported by the answers in the Swedish evaluation sheets where workers at the workplace were indicated most often.

According to Malchaire, Gebhardt & Piette (1999), the maximum time required to perform the risk assessment procedure on the ‘Observation’ level should be no longer than one hour. After applying stricter requirements to the data and reducing the sample size to 70 evaluation sheets, there were only two evaluation sheets where it was indicated that observers needed longer than one hour (a time of 75 minutes was indicated in one Finnish evaluation sheet and 105 minutes was indicated in one Swedish evaluation) to perform the risk assessment procedure. Based on the results, it can be concluded that the expected time for carrying out the cold risk assessment procedure at a workplace is between 20 and 30 minutes.

The statistically significant difference between the times taken to perform the whole risk assessment procedure by the Swedish and Finnish groups could have resulted from the significant differences in time taken to perform the preparation stage. A possible explanation for the differences in time needed to conduct the preparation stage is the fact that information was presented to the groups in different languages (although the content of the written information was identical) and that different groups of the authors had trained the observers.

The time to perform a risk assessment procedure would probably be longer if the stage of ‘Further procedures’ were included in the calculation of the total time. However, only 44% of the answer sheets had times indicated for this stage. Furthermore, there was no clear understanding among observers about what the further procedures should include (for example, some of them included the travel time to and from the observed worksite). Therefore, the total time was a sum of only three stages. On the other hand, the fact that the observers received training and instructions in person could have shortened the time needed to perform the risk assessment procedure. Another factor that might have reduced the time needed to perform the procedure is the fact that individual observers had tested the checklist and filled in the evaluation sheets several times (on average approximately 2.5 evaluation sheets per observer). However, the study design is such that it does not allow verifying the hypothesis of whether a learning effect made a difference in the time needed to conduct the cold risk assessment procedure after the checklists was used for the first, second or third time.

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Similarly to the results of field testing in the Nordic countries, the observational checklist was found to be a usable tool for cold risk assessment, even when applied to companies with a different approach to safety culture. The results corresponded in terms of the instructions provided for the checklist and summary table; the facility of the checklist and summary table and the suitability of the checklist (in regards to the structure and content) for identifying cold-related risk factors. Furthermore, it complies well on these aspects with the recommendations given by Malchaire, Gebhardt & Piette (1999) for the ‘Observation’ method. The fact that no signs of learning effects in the evaluation sheets filled in after conducting the risk assessment procedure for the first, second and third time were found strengthens the idea that the checklist is rather straightforward and easy to use.

According to the Nordic observers, a workers’ representative responsible for industrial safety and the workers themselves should carry out the assessment procedure at the workplace. On the contrary, the Russian observers indicated workers only in 7.5% of the evaluation sheets, giving priority to a safety engineer (indicated in 50.5% of evaluation sheets) and a foreman (indicated in 22.6% of evaluation sheets). This contradicts the recommendation of (Malchaire, Gebhardt & Piette (1999) that the persons performing the cold risk assessments should be the ones who are very well versed in the content of the work. In the case of Russian observers, it highlights a very interesting situation as the work safety engineer (category most often suggested by the observers) in one of the companies did not even know how many of the employees were working outdoors. The very low percentage of evaluation sheets where the alternative denoting the workers themselves was selected is likely an indication that the observers either have no interest or belief in their ability to influence or change their working environment.

According to Malchaire, Gebhardt & Piette (1999), the maximum time required to perform the risk assessment procedure on the ‘Observation’ level should be no longer than one hour. As each of the stages: preparation, realisation and analysis of results was most often described by the category of ‘less than 15 min’, the total time for performing the three categories is expected to be less than 45 minutes. There were differences in the categories chosen to describe the time needed to perform the last stage: discussion of results after conducting the cold risk assessment procedure for the first, second and third time. As the majority of the evaluation sheets filled in after the checklist was used for the first time indicated that no discussion took place on the possible preventive measures, the total time to carry out all four stages would be the same – under 45 minutes. After filling in the checklist for the second and third time, the absolute majority of the evaluation sheets suggested an expected total time for conducting all four stages of the assessment procedure to be a sum of four categories of ‘less than 15 min’, still in the line with the recommendations of Malchaire, Gebhardt & Piette (1999).

4.2. The validation of the checklist

The calculated mean M , HR , S and a change in mean body temperature ( bodyT ) as well as the reported subjective thermal sensations in the whole body, feet, hands and face for all activities are shown in the table 2 of Paper III. bodyT for each activity is also depicted in figure

1 of Paper III. Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT for each activity are portrayed in figures 2–7 of Paper III. The results from the subjects’ evaluations of the thermal conditions with the help of the checklist as well as the number of subjects who gave the same most common score for a particular cold-related risk factor during each performed activity are reported in table 3 of Paper III.

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The number of subjects who assessed the particular cold-related risk factor by means of the checklist in conformity to their reported thermal sensations and measured skin temperatures varied most often from five to eight for the factors that were relevant to the performed activity (see table 1). In some rare cases, only one, two or three subjects gave evaluations of the particular cold-related risk factor that agreed to their thermal sensations and measured skin temperatures. In particular, this was the case for risk factors concerning the presence of light work and protection of extremities against cold, when several work tasks were performed under the same experiment. In the case of non-relevant factors, most often seven or all eight subjects gave scores corresponding to the instructions given to subjects prior to the experiment.

Table 1. The number of subjects who assessed the particular cold-related risk factor in accordance with the reported thermal sensations and measured skin temperatures or in agreement with given instructions, in the case of non–relevance.

ActivityRisk factor A B C D E F

Cold air 6 6 4 5 5 6 Wind/ air movements 5 7 7 6 7 7 Touching cold surfaces 6 8 8 8 8 8 Water/ liquids/ damp 8 7 7 7 7 7 Protective clothing against cold 4 8 8 8 8 8 Protection of extremities against cold 2 7 6 6 5 5 Use of PPE 6 8 8 8 7 8 Other problems:

Long–term cold exposure 6 8 5 7 5 8 Light work 3 7 5 6 7 1 Highly varying workload 4 7 7 7 7 5 Varying thermal environments 8 7 5 7 8 6 Slipperiness 7 7 7 7 8 7 Insufficient lighting 7 8 8 8 8 8

Therefore it has to be kept in mind that in some cases up till around 35% of answers provided in the checklist might not necessarily reflect the real situation at the workplace. This is an important factor to take into consideration when planning cold risk prevention measures, as some observers might overestimate the protection against cold provided at the workplace.

4.3. Risk factors in the cold work The used checklist was observational in its nature and would indicate only potential areas where problems might exist. Furthermore, the ratings of experienced problems were self-reported by observers and could not be verified by other means. It should also be kept in mind that certain cold-related risk factors (‘cold air’, ‘protection of extremities against cold’, ‘long-term cold exposure’, ‘light work’, ‘highly varying workload’ and ‘varying thermal environments’) were found to be experienced by observers differently depending on the branch of economic activity that their workplace represented.

Slipperiness was found to be a problem at the workplace in both regions: Nordic countries and north-western Russia; however, the Russian observers experienced it to be more acute, as

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it was rated as a problem more often and of a greater severity. Certain differences regarding the experienced slipperiness were reported in the Nordic checklists representing the outdoor work activities. According to the observers, it was a problem under cold temperatures, but it did not cause any inconvenience under very cold temperatures.

Cold air and contact with cold surfaces were rated the same by Nordic and Russian observers. The observers experienced them as slight problems. Wind/ air movements and interchange between light and heavy work were perceived by both groups of observers as slightly problematic, although to a higher extent by Russian observers.

The Nordic observers did not perceive lighting as insufficient, though Russian observers did when asked whether this cold-related risk factor was problematic or not. Exposure to water/ liquids/ damp was marked as slightly problematic in the observed workplaces with more frequent complaints among the Russian observers. This problem was characterised as considerable by the Nordic indoor workers (in the fish factories).

Unexpectedly, the majority of observers thought that the protective clothing against cold provided in the workplaces was sufficient. This is especially surprising in the case of the Russian observers as the majority of them were using their own old clothes that they would not use in their private lives any more. On the other hand, Aptel (1988) found that the workers (exposed to artificial cold between –30 and +10ºC) were able to evaluate their own needs in thermal clothing insulation with sufficient accuracy if the required clothing insulation (IREQ) was under 1.50 clo. Furthermore, whenever it was possible, the workers preferred to wear thermal clothing insulation that provided them with thermal comfort.

In general, the majority of Nordic observers were satisfied with the level of extremity protection provided at the workplace, while the Russians claimed it to be partially insufficient. However, in the group of indoor Nordic workers it was most often indicated that protection of extremities against cold was fairly good rather than sufficient. It should be taken into account that cold stress can be perceived very individually. For example, Hammarskjöld, Harms-Ringdahl & Ekholm (1992) found that ten carpenters perceived the cooling of the hand (after being exposure to moderate cold for one hour) very individually and the sensation of cold exposure was rated from ‘neither warm nor cold’ to ‘very, very cold’.

The majority of Nordic observers thought that it was easy to integrate protection against cold with personal protective devices so that they did not interfere with the performed work activities, while Russian observers experienced it as somewhat difficult.

In the checklists returned by Nordic observers it was most often marked that long-term cold exposure (continuously for more than two hours) was not a hazard at their workplaces, while Russian observers marked it most often as problematic. This could be explained by a more generous policy regarding warm-up breaks in the Nordic countries compared to the observed companies in north-western Russia. Interestingly the Nordic indoor workers had marked it as slightly problematic compared to the ‘no problem’ appearing most often in the checklists evaluating outdoor working conditions.

In general, light work such as, for example, standing while measuring or monitoring, was not a source of cold-related problems in the observed workplaces. However, according to the Russian observers it became somewhat of a problem if the work was to be carried out under very cold temperatures.

In general, frequent moving between indoor and outdoor conditions (from warm to cold environments) was judged as causing no problems at the observed workplaces. However, the majority of Russian observers would answer that it is a problem when asked whether this cold-related risk factor was problematic or not while not being required to specify how severe

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the problem was. It was also most often indicated as slightly problematic in the majority of Nordic checklists representing outdoor work under very cold conditions.

The results presented in the thesis are similar to the ones reported by Gavhed, Kuklane, Karlsson & Holmér (1999a) in the study of harbour workers, telecommunication technicians, mast workers and customs personnel (43 respondents) further supported by the field study of eight mast workers during maintenance and reparation activities (Gavhed, Kuklane, Karlsson & Holmér, 1999b). The studies of cold working conditions at dairy farms in Sweden (Gavhed, Fredriksson, Kuklane, Holmér & Norén, 2002) and Finland (Tuure, 2003) report similar findings as well.

4.4. The validation of the standard

The ISO standardisation helps to avoid similar scales with similar wording in the tabulated values, corresponding to different values of metabolic rate, which usually causes problems in the practical field work.

Attempts have been made to modify the Edholm scale, for example, Long & Louhevaara (1992) proposed a modified Edholm scale for manual handling jobs.

The results of the present study are consistent with those reported by Ilmarinen, Knauth, Klimmer & Rutenfranz (1979) and Kähkönen et al. (1992). The first study showed that the occupational activities in industries with no heavy physical work had been overestimated by the Edholm scale in the categories ‘Sitting or standing with very light movements or activities’ and ‘Activities with low intensity’, therefore that they should be placed one category lower. The second study reported that the metabolic rate derived from the Edholm scale was higher than from the ISO 7243 (1989) tables.

The ISO standard sets an acceptability limit of 15 % for the relative errors calculated for the different indirect methods and 5 % in measurements and time studies. Thus, if these acceptability limits are considered, only MISO for the tasks 1 and 5 are the same as MMeas.However, even after considering the errors limits MEdh does not become equal to MMeas.

In addition, the ISO 8996 states that the metabolic rate can vary from person to person by about 5 % for the same work and under the same working conditions. According to the standard, metabolic rate values vary with the certain limits because of the influence of work technique, work speed and differences between the work equipment. The subjects participating in the present study used different technique in the tasks 2 and 6, while in the other tasks no differences were observed. As these inter-individual differences were observed even in very stereotyped tasks under laboratory conditions, it is concluded that the habits and the working procedures adopted by the subjects are very important to determine the energy expenditure under field conditions. All the subjects used the same equipment during the whole experiment, thus the variation of MMeas subject to subject did not result from the different equipment. However, three of the tasks were not paced by the experimenter and it might have been a source of differences in MMeas values.

The energetic cost of singular tasks in the ISO 8996 tables or the Edholm scale are given for a standard male person (1.7 m height, 70 kg weight and a body surface of 1.8 m2) which can explain errors for subjects different from the standard. The anthropometric characteristics of the ‘average’ person calculated for the subjects of the present study are close to those indicated in the standard, although the range of values was rather wide: height varied from 1.55 to1.92 m, weight varied 56 - 110 kg and body surface varied from 1.59 to 2.26 m2.

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Additionally, the ‘average’ subject in this study was younger (range of 21 - 38 years) than the reference person (35 years old) in the ISO 8996.

The subjective evaluation of perceived exertion was more correlated to the MMeas than to the net cardiac cost (NCC), which is in contrast to the consistency of Borg scale. The same observation of heart rate (HR) inconsistency to Borg scale was reported by Costa, Berti & Betta (1989). It is plausible that the subjective evaluation of the work strain does not refer only to the overall sensation of fatigue, but also to local strains, in particular on the musculoskeletal system, due to bad postures or repetitive movements.

The Edholm scale expresses the metabolic cost of physical activity as a multiple basal metabolic rate (BMR). It is based on two assumptions: first, that the inter-individual variability for any group of subjects in total energy expenditure is reflected in their BMR (Shetty & Soares, 1988). Secondly, that BMR can, for reasons of simplicity, be predicted from body weight using linear equations specific for age and sex. The part of the Edholm scale dealing with the BMR was not examined in the study. Thus for the full validation of the Edholm scale studies on correlation of metabolic rates estimated as multiples of BMR and the actual measured should be conducted on different levels of work load.

22

5. Conclusions

The Nordic subjects found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment, the interference of the method with the observed work, the adequacy of the instructions and the facility of the checklist.

Although the Russian observers found the observational checklist to be a usable tool for cold risk assessment, interestingly, the workers at the observed workplaces would prefer that someone other than themselves should conduct cold risk assessment by means of the checklist.

The number of subjects who assessed the particular cold-related risk factor by means of the checklist in conformity to their reported thermal sensations and measured skin temperatures varied most often from five to eight for the factors that were relevant to the performed activity. In some rare cases, only one, two or three subjects gave evaluations of the particular cold-related risk factor that agreed to their thermal sensations and measured skin temperatures. In particular, this was the case for risk factors concerning the presence of light work and protection of extremities against cold, when several work tasks were performed under the same experiment. In the case of non-relevant factors, most often seven or all eight subjects gave scores corresponding to the instructions given to subjects prior to the experiment.

The majority of the cold-related risk factors were rated differently by Nordic and Russian observers in term of either the chosen severity of the problem (‘no problem’, ‘slight problem’ or ‘considerable problem’) or the frequencies of ratings along these categories. Five factors (‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’ and ‘highly varying workload’) were most often rated as slightly problematic and two factors (‘protective clothing against cold’ and ‘light work’) as causing no problems by both groups. The remaining six factors (‘protection of extremities against cold’, ‘use of PPE’, ‘long-term cold exposure’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’) were rated differently by Nordic and Russian observers, and the latter indicated less favourable situations at the observed workplaces.

Only a few factors had different ratings if various variables (nature of work, ambient temperatures and sector of economic activities) were taken into account.

The metabolic rates derived from the Edholm scale (MEdh) overestimated five of six manual handling activities by 34–50% ( =.05). The metabolic rates derived from ISO 8996 (MISO)overestimated all activities by 7–38% ( =.05).

23

6. Possible future investigations

The developed checklist is a tool intended for use in the second stage ‘Observation’ of the four step (screening, observation, analysis, expertise) strategy for evaluation and prevention of risks related to cold. A further step could be to develop risk assessment and management tools for the third stage ‘Expertise’ for the target group of people trained in occupational safety and ergonomics.

The usability of the checklist should be tested in other types of industries representing a wider variety of workplaces, for example freezer rooms, oil and gas platforms, fishing ships, etc. where exposure to cold is common.

The developed checklist needs to be validated further in order to check the degree of inter- and intra-observer variability.

Each company has its own work safety policies and routines. Other possible studies could investigate how successfully a strategy for cold risk assessment could be integrated into the overall safety management program of a company.

24

7. References

ACGIH. (1989). Threshold limit values and biological exposure indices for 1989–1990. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists.

Aptel M. (1988). Comparison between required clothing insulation and that actually worn by workers exposed to artificial cold. Applied Ergonomics, 19(4) 301–5.

Arbetsmiljöverket. (2001). Systematiskt arbetsmiljöarbete: Arbetsmiljöverkets föreskrifter om systematiskt arbetsmiljöarbete och allmänna råd om tillämpningen av föreskrifterna (Systematic Work Environment Management. Provisions of the Swedish Work Environment Authority on Systematic Work Environment Management, together with General Reccomendations on the implementation of the Provisions). Solna: Arbetsmiljöverket.

Berquist, K. & Abeysekera, J. (1994). Research needs to improve wearibility of personal protective devices and clothing (ppds) in the cold climate. In: Proceedings of Polar Tech'94. (pp. 369–375). Luleå, Sweden.

BS 8800. (1996). Guide to occupational health and safety management systems. London: British Standards Institution.

Borg, G. (1970). Perceived exertion as an indicator of somatic stress. Scandinavian Journal of Rehabilitation Medicine, 2(2), 92–98.

Burtan, R.C. (1994). Work under low temperatures and reactions to cold. In: C. Zenz, B. O. Dickerson & E. P. Horvath, Jr (Eds.), Occupational medicine. (pp. 334–342). St. Louis: Mosby.

Burton, A.C. & Edholm, O.G. (1969). Man in a cold environment: physiological and pathological effects of exposure to low temperatures. New York: Hafner Publishing Company, Inc.

Canadian Centre for Occupational Health and Safety. (1995). Cold weather worker's safety guide. Hamilton: The Centre (CCOHS).

Chen, F., Nilsson, H. & Holmér, I. (1994). Cooling responses of fingers in contact with an aluminium surface. American Industrial Hygiene Association Journal, 55(3), 218–222.

Chen, F. & Holmér, I. (1998). Subjective sensation during local cold exposure. In: K. Kuklane & I. Holmér (Eds.), Problems with cold work. (pp. 240–242). Solna, Sweden: National Institute for Working Life (Arbetslivsinstitutet), Arbete och Hälsa, 1998:18.

Cheung, S.S., Montie, D.L., White, M.D. & Behm, D. (2003). Changes in manual dexterity following short-term hand and forearm immersion in 10ºC water. Aviation, Space, and Environmental Medicine, 74(9), 990–993.

Costa, G., Berti, F. & Betta, A. (1989). Physiological cost of apple-farming activities. AppliedErgonomics, 20(4), 281–286.

Council of the European Communities. (1989). Council Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work. Official Journal L 183, 29/06/1989.

Edholm, O. G. (1966). The assessment of habitual activity. In: K. Evang & K. Lange Andersen (Eds.), Physical activity in health and disease. (pp. 187-197). Oslo: Universitets forlaget.

25

Enander, A. (1986). Sensory reactions and performance in moderate cold. Solna, Sweden: National Board of Occupational Safety and Health (Arbetarskyddsstyrelsen), Arbete och Hälsa, 1986:32.

Enander, A. (1987). Effects of moderate cold on performance of psychomotor and cognitive tasks. Ergonomics, 30(10), 1431–1445.

Evenson, E. (1994). Cold environments. In: P. H. Wald & G. M. Stave (Eds.), Physical and biological hazards of the workplace. (pp. 113–124). New York: Van Nostrand Reinhold.

Gavhed, D., Kuklane, K., Karlsson, E. & Holmér, I. (1999a). En pilotstudie om arbete i kyla - frågeundersökning och fältstudie. Stockholm: Arbetslivsinstitutet. Report 4.

Gavhed, D., Kuklane, K., Karlsson, E. & Holmér, I. (1999b). Mastarbete i kyla. Stockholm: Arbetslivsinstitutet. Report 22.

Gavhed, D., Fredriksson, K., Kuklane, K., Holmér, I. & Norén, O. (2002). Arbete i kyla i mjölkproduktionsanläggningar. Kartläggning och studie av termiska arbetsmiljöproblem. Uppsala: Swedish Institute of Agricultural and Environmental Engineering. Report 290.

Geng, Q., Karlsson, E. & Holmér, I. (2000). Manual performance after gripping cold surfaces with and without gloves. In: K. Kuklane & I. Holmér (Eds.), Ergonomics of protective clothing. Proceedings of the NOKOBETEF 6 and 1st European Conference on Protective Clothing, Stockholm, Sweden, May 7–10, 2000. (pp. 208–211). Stockholm, Sweden: National Institute for Working Life (Arbetslivsinstitutet), Arbete och Hälsa, 2000:8.

Giesbrecht, G.G., Arnett, J.L., Vela, E. & Bristow, G.K. (1993). Effect of task complexity on mental performance during immersion hypothermia. Aviation, Space, and Environmental Medicine, 64(3, Section I), 206–211.

Giesbrecht, G.G., Wu, M.P., White, M.D., Johnston, C.E. & Bristow, G.K. (1995). Isolated effects of peripheral arm and central body cooling on arm performance. Aviation, Space, and Environmental Medicine, 66(10), 968–975.

Hammarskjöld, E., Harms-Ringdahl, K. & Ekholm, J. (1992). Reproducibility of carpenters' work after cold exposure. International Journal of Industrial Ergonomics, 9(3), 195–204.

Hassi, J., Juopperi, K., Remes, J., Rintamäki, H., Näyhä, S., Ervasti, O., Juosilahti, P. & Vartiainen, E. (1998). FINRISKI'97 Kylmäaltistusalaotos. Tutkimus suomalaisten kylmäaltistuksesta, -haitoista ja kylmältä suojautumisen tavoista. Tutkimuksen toteutus ja perustaulukot. Oulu: Finnish Institute of Occupational Health. Report 4.

Havenith, G., Van de Linde, E.J.G. & Heus, R. (1992). Pain, thermal sensation and cooling rates of hands while touching cold materials. European Journal of Applied Physiology and Occupational Physiology, 65(1), 43–51.

Herington, T.N. & Morse, L.H. (1995). Occupational injuries: evaluation, management, and prevention. St. Louis: Mosby.

Hoffman, R.G. & Pozos, R.S. (1989). Experimental hypothermia and cold perception. Aviation, Space, and Environmental Medicine, 60(10), 964–969.

Holmér, I. (1991). Assessment of cold stress. Arctic Medical Research, 50(Suppl. 6), 83–88.

Holmér, I. (1993). Work in the cold: Review of methods for assessment of cold exposure. International Archives of Occupational and Environmental Health, 65(3), 147–155.

Holmér, I. (1994). Cold stress: Part I - Guidelines for the practitioner. International Journal of Industrial Ergonomics, 14(1–2), 139–149.

26

Holmér, I. (1998). Cold Indices and standards. In: J. M. Stellman (Ed.), Encyclopaedia of occupational health and safety. (pp. 4248–4255). Geneva: ILO.

Holmér, I. (1999). Risk assessment in cold environment. Barents Newsletter, 1(3), 77–79.

Holmér, I., Granberg, P.-O. & Dahlström, G. (1998). Cold environments and cold work. In J. M. Stellman (Ed.), Encyclopaedia of occupational health and safety. (pp. 4229–4248). Geneva: ILO.

Howard, R.L., Kraemer, W.J., Stanley, D.C., Armstrong, L.E. & Maresh, C.M. (1994). The effects of cold immersion on muscle strength. Journal of Strength and Conditioning Research, 8(3), 129–133.

Ilmarinen, J., Knauth, P., Klimmer, F. & Rutenfranz, J. (1979). The applicability of the Edholm scale for activity studies in industry. Ergonomics, 22(4), 369–376.

ISO 7243. (1989). Hot environments - Estimation of the heat stress on working man, based on the WBGT-index. Geneva: ISO.

ISO 8996. (1990). Ergonomics - Determination of metabolic heat production. Geneva: ISO.

ISO 9886. (1992). Evaluation of thermal strain by physiological measurements. Geneva: ISO.

ISO 9920. (1995). Ergonomics of the thermal environment - Estimation of the thermal insulation and evaporative resistance of a clothing ensemble. Geneva: ISO.

ISO/TR 11079. (1993). Evaluation of cold environments - Determination of required clothing insulation (IREQ). Geneva: ISO.

Jay, O. & Havenith, G. (2004). Finger skin cooling on contact with cold materials: A comparison between male and female responses during short-term exposures. EuropeanJournal of Applied Physiology, 91(4), 373–381.

Kuklane, K., Geng, Q. & Holmér, I. (1998). Effect of footwear insulation on thermal responses in the cold. International Journal of Occupational Safety and Ergonomics, 4(2), 137–152.

Kuklane, K. (2000). Footwear for cold work: a limited questionnaire survey. In: K. Kuklane & I. Holmér (Eds.), Ergonomics of protective clothing. Proceedings of the NOKOBETEF 6 and 1st European Conference on Protective Clothing, Stockholm, Sweden, May 7–10, 2000. (pp. 67–70). Stockholm, Sweden: National Institute for Working Life, (Arbetslivsinstitutet), Arbete och Hälsa, 2000:8.

Kähkönen, E., Nykyri, E., Ilmarinen, R., Ketola, R., Lusa, S., Nygård, C.-H. & Suurnäkki, T. (1992). The effect of appraisers in estimating metabolic rate with the Edholm scale. Applied Ergonomics, 23(3), 186–190.

Long, A. F. & Louhevaara, V. (1992). Computerised collection and analysis of minute by minute physical activity and work phase data. In: M. Mattila & W. Karwowski (Eds.), Computer Applications in Ergonomics, Occupational Safety and Health (pp. 445–451). Amsterdam: Elsevier Science.

Malchaire, J., Gebhardt, H.J. & Piette, A. (1999). Strategy for evaluation and prevention of risks due to work in thermal environments. Annals of Occupational Hygiene, 43(5), 367–376.

Mäkinen, T. & Hassi, J. (2002). Usability of ISO thermal standards for cold risk assessment in the workplace. International Journal of Circumpolar Health, 61(2), 142–153.

27

Nowak, D.A. & Hermsdorfer, J. (2003). Digit cooling influences grasp efficiency during manipulative tasks. European Journal of Applied Physiology, 89(2), 127–133.

Oksa, J. (2000). Neuromuscular performance limitations in cold. International Journal of Circumpolar Health, 61(2), 154–162.

Oksa, J., Rintamäki, H. & Mäkinen, T. (1991). Cooling alters force-velocity relationship of upper body and arms. Proceedings of the International Conference on the Human-Environment System, Tokyo, Japan, 3–7 December 1991, 587–590.

Oksa, J., Rintamäki, H. & Mäkinen, T. (1992). Amount of subcutaneous fat modifies the cooling induced changes in muscular performance. In: W. A. Lotens & G. Havenith (Eds.), Proceedings of the Fifth International Conference on Environmental Ergonomics, Maastricht, The Netherlands. (pp. 200–201). Soesterberg, The Netherlands: Institute for Perception.

Oksa, J., Rintamäki, H. & Mäkinen, T. (1993). Physical characteristics and decrement in muscular performance after whole body cooling. Annals of Physiological Anthropology,67(4), 335–339.

Oksa, J., Rintamäki, H. & Rissanen, S. (1997). Muscle performance and electromyogram activity of the lower leg muscles with different levels of cold exposure. European Journal of Applied Physiology and Occupational Physiology, 75(6), 484–490.

Ozaki, H., Nagai, Y. & Tochihara, Y. (2001). Physiological responses and manual performance in humans following repeated exposure to severe cold at night. EuropeanJournal of Applied Physiology, 84(4), 343–349.

Parsons, K.C. (1993). Human thermal environments. London: Taylor & Francis.

Pathak, B. & Charron, D. (1987). Cold Stress. Hamilton: Canadian Centre for Occupational Health and Safety.

Pekkarinen, A. (1994). Occupational accidents occurring in different physical environments with particular reference to indoor and outdoor work. Oulu: University of Oulu. Doctoral Thesis.

Peterson, J.E. (1991). Industrial health. (2 ed.). Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists.

Ramsey, J.D., Burford, C.L., Beshir. M.Y. & Jensen, R.C. (1983). Effects of workplace thermal conditions on safe work behaviour. Journal of Safety Research, 14(3), 105–114.

Rintamäki, H., Mäkinen, T. & Gavhed, D. (1998). Effect of a wide hood on facial skin temperatures in cold and wind. In: K. Kuklane & I. Holmér (Eds.), Problems with cold work, Proceedings from an international symposium held in Stockholm, Sweden, Grand Hotel Saltsjöbaden, November 16–20, 1997. (pp. 58–59). Solna: Arbetslivsinstitutet, Arbete och Hälsa, 1998:18.

Risikko, T. & Anttonen, H. (1998). Use of personal heaters in cold work. In: K. Kuklane & I. Holmér (Eds.), Problems with cold work, Proceedings from an international symposium held in Stockholm, Sweden, Grand Hotel Saltsjöbaden, November 16–20, 1997. (pp. 29–30). Solna: Arbetslivsinstitutet, Arbete och Hälsa, 1998:18.

Risikko, T., Mäkinen, T., Påsche, A., Toivonen, L. & Hassi, J. (2003). A model for managing cold-related health and safety risks at workplaces. International Journal of Circumpolar Health, 62(2), 204–215.

28

Sawada, S., Araki, S. & Yokoyama, K. (2000). Changes in cold-induced vasodilatation, pain and cold sensation in fingers caused by repeated finger cooling in a cool environment. Industrial Health, 38(1), 79–86.

Shetty, P. S., & Soares, M. J. (1988). Variability in basal metabolic rates of man. In: K. Blaxter & I. MacDonald (Eds.), Comparative Nutrition (pp. 141–148). London: John Libbey.

Statistics Sweden. (2000). The work environment 1999. Statistical bulletin. AM 68 SM 0001. Stockholm: Statistics Sweden.

Statistics Sweden. (2002). The work environment 2001. Statistical bulletin. AM 68 SM 0201. Stockholm: Statistics Sweden.

Statistics Sweden. (2005). Work-related disorders. Statistical bulletin. AM 43 SM 0501. Stockholm: Statistics Sweden.

Stocks, J.M., Taylor, N.A.S., Tipton, M.J. & Greenleaf, J.E. (2004). Human physiological responses to cold exposure. Aviation, Space, and Environmental Medicine, 75(5), 444–457.

Thomas, J.R., Ahlers, S.T., House, J.F. & Schrot, J. (1989). Repeated exposure to moderate cold impairs matching-to-sample performance. Aviation, Space & Environmental Medicine, 60(11), 1063–1067.

Tochihara, Y. (2005). Work in artificial cold environments. Journal of Physiological Anthropology and Applied Human Science, 24(1), 73–76.

Tochihara, Y., Ohkubo, C., Uchiyama, I. & Komine, H. (1995). Physiological reaction and manual performance during work in cold storages. Applied Human Science, 14(2), 73–77.

Tochihara, Y., Ohnaka, T., Tuzuki, K. & Nagai, Y. (1995). Effects of repeated exposures to severely cold environments on thermal responses of humans. Ergonomics, 38(5), 987–995.

Tuure V-M. (2003). Cold working environments on diary farms in Finland. International Journal of Circumpolar Health, 62(2), 190–203.

Wilkerson, J.A. (1986). Other localized cold injuries. In: J. A. Wilkerson, C. C. Bangs, J. S. Hayward & J. M. Tuttle (Eds.), Hypothermia, frostbite and other cold injuries: prevention, recognition and prehospital treatment. (pp. 96–101). Seattle, Washington: The Mountaineers.

Youle, A. (1995). The thermal environment. In: J. M. Harrington & K. Gardiner (Eds.), Occupational hygiene. (pp. 191–227). Oxford: Blackwell Science.

APPENDIX I

Copyright ©: Kylmätyöohjelma, Työterveyslaitos, Aapistie 1, 90220, Oulu

Tarkistuslista kylmän haittatekijöiden tunnistamiseen

Kuinka käytän tarkistuslistaa?

1. Muodosta yleiskatsaus työpaikasta. Tee karkea luokitus niistä työkokonaisuuksista, jotka toteutetaan päivittäin tai tulevana ajanjaksona, jos työpaikalla on useita erilaisia työkokonaisuuksia. Täytä jokaiselle työkokonaisuudelle oma tarkistuslista. Mikäli ei ole mahdollista havainnoida kaikkia työkokonaisuuksia toteuta havainnointi myöhemmin. Jos useampi työntekijä osallistuu työkokonaisuuden toteuttamiseen havainnoi työntekijää, jolla on mielestäsi eniten ongelmia kylmään liittyen

2. Katso läpi tarkistuslistan jokainen kohta ja merkitse vaihtoehto, joka parhaiten vastaa tilannetta. 0 osoittaa, että tilanne on kunnossa, 1 tarkoittaa, että tiettyjä ongelmia kylmään liittyen on olemassa, 2 osoittaa, että on ongelmia, joihin voi liittyä alentuneen toimintakyvyn ja terveyden riski.

3. Tee merkintöjä jokaiseen kohtaa, joilla on yhteyttä havainnoitavaan työtehtävään (esim. puutteellinen suojaus tuulelta, käsineitä ei käytetä, tietyt osat kehosta ovat kosketuksissa kylmiin pintoihin) Nämä merkinnät helpottavat tulosten arviointia.

4. Milloin tarkistuslistaa tulisi käyttää? a) muutaman kerran talven aikan (esim. kerran kuukaudessa) b) ympäristöolosuhteiden muuttuessa merkittävästi c) kun työtehtävät muuttuvat merkittävästi d) seuratessa ovatko kylmän hallintatoimenpiteet olleet riittäviä.

1

Tarkistuslista kylmän haittatekijöiden tunnistamiseen Yrityksen nimi: …....………………………....………………………....…...…………. Pvm: …....………………………....…...………….……...…

Havainnoitava työtoiminto:…....………………………....…………....…… Lämpötila:……………………………………… °CTuuli:………………………………………………… m/s

Pisteytys, joka liittyy Ongelman vakavuuteen: 0 ei tarvetta 1 toimenpiteitä suo- 2 tarve välittömille

toimenpiteille sitellaan pitkällä korjaustoimenpiteilletähtäimellä

1. Kylmä ilma 0 Ilman lämpötila ei aiheuta mitään ongelmia1 Ilman lämpötila aiheuttaa tiettyjä ongelmia2 Ilman lämpötila aiheuttaa selviä ongelmia

Huomautus:_______________________________________________________________

2. Tuuli/ilman liike 0 Ei ilman liikettä1 Kevyt ilman liike (esim. vedon tunne, kevyt tuuli)2 Voimakas ilman liike (esim. voimkas tuuli, joka puhaltaa ajoittain tai toistuvasti)

Huomautus:_______________________________________________________________

3. Kosketus kylmiin pintoihin käsiteltäessä työkaluja/materiaaleja tai kunistutaan, ollaan polvillaan tai maataan kylmillä pinnoilla

0 Ei juuri ollenkaan 1 Työskentelyä lyhyen ajan ohuilla käsineillä, istuen, polvillaan tai maaten kylmillä pinnoilla2 Työskentelyä paljain käsi tai pitkiä aikoja istuen, polvillaan, seisten ja maaten kylmillä

pinnoillaHuomautus:_______________________________________________________________

4. Altistuminen vedelle/nesteille/kastumiselle0 Ei altistumista1 Lyhyitä altistumisjaksoja (esim. kylmien materiaalien käsittely, vesi- tai lumisade)2 Pitkiä altistumisjaksoja (esim. jatkuva kylmien nesteiden tai märkien materiaalien käsittely

jne.)Huomautus:_______________________________________________________________

5. Kylmänsuojavaatetus (ei kädet, jalat ja pää) 0 Riittävä1 Osittain riittämätön (esim. vain joitakin talvivaattekappaleita käytössä)2 Riittämätön (esim. kylmänsuojavaatetusta ei käytetä ollenkaan vaikka niitä tarvitaan)

Huomautus:_______________________________________________________________


2

6. Suojautuminen kylmältä: kädet, jalat, pää (arvioidaan vallitsevan olosuhteen mukaan, suluissa esitetyt esimerkit pätevät lähinnä suojautumiseen hyvin kylmässä ilmassa)

0 Riittävä (esim. kintaat ja aluskäsineet; talvisaappaat, jossa paksut pohjat sekä irtopohjalliset tuulenpitävä talvihattu, joka peittää korvat)

1 Melko hyvä (esim. vuorelliset käsineet; talvikengät, jossa paksut pohjat; turvakypärä, jossa alusmyssy tai ei-tuulenpitävä hattu )

2 Riittämätön (esim. vuorettomat käsineet, ei käsineitä; kengät, jossa ohut pohja; pelkkäturvakypärä tai paljas pää) Huomautus:_______________________________________________________________

7. Henkilösuojainten käyttö (kypärä, kuulosuojaimet, jne.)0 Ei haittaa1 Haittaa jossain määrin (esim. kömpelyys, liikerajoitukset, heikentynyt suoja kylmää

vastaan)2 Huomattava haitta (esim. huomattavia vaikeuksia yhdistää kylmänsuojavaatetus ja muut

henkilösuojaimet tai kylmänsuojavaatetusta/henkilösuojaimia ei käytetä ollenkaan) Huomautus:_______________________________________________________________

8. Muut kylmään liittyvät ongelmat 0 1 2

Pitkäaikainen kylmäaltistus/työskentely kylmässä (esim. yhtäjakoisesti >yli 2 tuntia)Kevyt työ (esim. mittaustyö, valvonta yms.)Lämmöntuotoltaan hyin vaihteleva työ (kevyt/raskas) Vaihtuvat lämpöolosuhteet (esim. liikkuminen sisä- ja ulkotilojen välillä) LiukkausRiittämätön valaistusMuu tekijä, mikä? _______________________________________________________


3

Tarkistuslistan tulosten arviointi sekä hallintatoimenpiteiden valinta

Merkitse pisteet (0, 1, 2) tarkistuslistan kustakin kohdastaTaulukkoon 1 kohtaan pisteet.Kohtaan muut ongelmat täytetään vain korkein saatu pistemäärä eri osakysymyksistä. Josuseassa kysymykessä/kohdassa on korkein pistemäärä, niin yksi numero riittää. Tulostenarvioinnin ja hallintatoimenpiteiden valinnan osalta tarkistetaan kukin osakohta erikseen tarkistuslistasta.Piste = 1 , (vähäinen ongelma) osoittaa, ettei lisähallintatoimenpiteitä tarvita juuri nyt. Tulos on kuitenkin syytä huomioida tulevaisuudessa parannettaessa yrityksen työterveys- ja työsuojelukäytäntöjä.Pisteet = 2 (vakava ongelma) tarkoittaa, että välittömiin korjaustoimenpiteisiinhaitan/haittojen vähentämiseksi tulee ryhtyä. Esimerkkejä eri kylmän hallintakeinoistalöytyy esim. kylmäriskien hallintamallista.Kirjaa ehdotus toteutettavista hallintatoimenpiteistä Taulukkoon 1. Jos ongelmia ei voida ratkaista yksinkertaisesti toteutettavilla keinoilla, rastita kohta lisäselvitys tarpeen. Arvioitaessa ja valitessa hallintatoimenpiteitä tulee olla tietoinen siitä,että tiettyjentekijöiden välillä on yhteisvaikutusta, esim. kylmä ilmalla on yhteisvaikutus tuulen/ilmanliikkeiden, kylmänsuojavaatetuksen, sekä kylmänsuojauksen (kädet, pää ja jalat kanssa. Samoin vedellä/nesteillä/märkyydellä on yhteisvaikutus kylmien pintojen kosketettamisensekä kylmänsuojavaatetuksen kanssa jne. Tämä yhteisvaikutus voi lisätä kylmään liittyviäriskejäKeskustele yrityksen johdon kanssa mitkä hallintatoimenpiteistä toteutetaan Sovi päivämäärä uudelleentarkistuksen toteuttamiseksi

Taulukko 1: Tulosten yhteenveto ja hallintatoimenpiteet

Toteutus

01

2

Ei tarvetta toimenpiteilleToimenpiteitä suositellaanpitkällä tähätimelläTarve välittömille korjaus-toimenpiteille

Pist

eet Hallintatoimenpide

Ei Kyllä

Lisä-selvitystarpeen

Uusinta-tarkastus-

pvm

1 Kylmä ilma

2 Tuuli/ ilman liike

3 Kosketus kylmiinpintoihin

4 Vesi/ nesteet/ märkyys

5 Kylmänsuojavaatetus

6 Suojautuminen kylmältä:kädet, jalat ja pää

7 Henkilösuojainten käyttö

8 Muut ongelmat

………………………… ………………… ……………………(Vastuullinen henkilö) (Päivämäärä) (Hyväksyntä)


Copyright ©: Thelma AS, P.O. BOX 6170, Sluppen, 7435 Trondheim

Sjekkliste for bedømmelse av kuldeproblemer

Hvordan skal sjekklista benyttes?

1. Skaff en oversikt over arbeidsplassen. Gjør en grov oppdeling av de aktiviterer som utføres daglig og i nærmeste tidsperiode. Bruk en separat sjekkliste for hver aktivitet. De aktiviteter som ikke kan observeres, kan bedømmes senere. Om flere personer deltar i arbeidsaktiviteten, bedømmes det verste tilfellet.

2. Gå gjennom hvert punkt i sjekklista og fyll i det poengalternativet som stemmer best. ˝0˝ viser at tilstanden er god, ˝1˝ viser at det finnes visse problemer uten at de er akutte, mens ˝2˝ viser at det finnes problemer som kan innebære risker i forbindelse med arbeid i kulde og som kan påvirke både arbeidsresultatet og helse – tiltak bør snarest iverksettes.

3. Gjør anmerkninger til hvert punkt som har sammenheng med den aktuelle situasjonen (f.eks., arbeidstakeren har dårlig beskyttelse mot vind; man bruker ingen handsker; kroppsdel som er i kontakt med kalde overflater, osv.). Slike anmerkninger letter tolkningen av resultatet.

4. Når skal sjekklisten brukes? a) noen ganger i løpet av vintersesongen (en gang per måned); b) ved større endring av de ytre forholdene (klimaet, osv.); c) når arbeidsoppgavene forandres betydelig; d) for å undersøke om gjennomførte tiltak har vært effektive.


1

Sjekkliste for å bedømme problemer med kulde Navn på bedrift:…....………………………....………………………… Dato:……………...…………………....…………...Observert arbeidsaktivitet:……………...………………………. Temperatur:……….………….…….…….….… °C Vind:….…….….………….…….….………….…….….… m/s

Poeng relatert til problem: 0 Ingen tiltak 1 Tiltak anbefales 2 Tiltak bør

nødvendig på lengre sikt iverksettes snarest

1. Kald luft 0 Kulden forårsaker ingen problemer 1 Kulden forårsaker visse problemer 2 Kulden forårsaker betydelige problemer Kommentarer:______________________________________________________________

2. Vind/ trekk0 Vindstille 1 Lette luftbevegelser (f.eks., trekk, svak vind) 2 Sterke luftbevegelser (f.eks., sterk vind blåser hele tiden eller av og til)

Kommentarer:______________________________________________________________

3. Kontakt med kalde flater i forbindelse med håndtering av verktøy/materialer eller ved sitting eller ligging på kalde flater

0 Nesten aldri 1 Korte perioder av arbeide med tynne hansker, sittende, knelende eller liggende på kalde flater2 Arbeide med bare hender, lange perioder med sitting, kneling eller ligging på kalde flater Kommentarer:______________________________________________________________

4. Utsatt for vann/ væsker/ fukt 0 Nei 1 Korte perioder (noen minutter, f.eks., håndtering av våte materialer eller ved regn eller snø) 2 Lange perioder (f.eks., langvarig håndtering av kalde væsker/våte materialer o. l.) Kommentarer:______________________________________________________________

5. Beskyttelsesklær mot kulde (unntatt hender, føtter, hode) 0 Tilstrekkelig 1 Delvis utilstrekkelig (f.eks.,, bare deler av beskyttelsesklær mot kulde anvendes til tross for

at det er nødvendig) 2 Utilstrekkelig (f.eks., ingen beskyttelsesklær mot kulde anvendes til tross for at det trengs) Kommentarer:______________________________________________________________


2

6. Beskyttelse mot kulde: hender, føtter, hode (bedømmes i forhold til det observerte klimaet; eksemplene gjelder først og fremst beskyttelse mot riktig kaldt klima).

0 Tilstrekkelig (f.eks., tykke votter/hansker med tynne hansker inni; vintersko med tykke såler og innleggssåler; vindtett isolert hodeplagg som dekker ørene) 1 Delvis utilstrekkelig (f.eks., forete votter; vintersko med tykke såler; vernehjelm med

innerlue eller hodeplagg som ikke er vindtett) 2 Utilstrekkelig (f.eks., usisolerte votter eller ingen votter; sko med tynne såler; bare

vernehjelm eller barhodet) Kommentarer:______________________________________________________________

7. Bruk av personlig verneutstyr, PPE (vernehjelm, hørselsvern, forklede, o. l.) 0 Ingen ulemper 1 Noen ulemper (f.eks., økt klumpethet eller noe begrenset bevegelighet, dårligere

kuldebeskyttelse)2 Betydelige ulemper (f.eks., betydelige problemer med å forene personlig verneutstyr med

beskyttelsesklær mot kulde, eller/og verneutstyr brukes ikke) Kommentarer:______________________________________________________________

8. Andre problemer som har sammenheng med kulde 0 1 2

Lang oppholdstid i kulde Lett arbeide (f.eks., avlesning av måleinstrumenter, vakthold, el. l.) Varierende lett og tungt arbeid (f.eks., for varm (svette) ved tungt arbeid og nedkjøling

ved etterfølgende lett arbeid) Varierende omgivelsesbetingelser (f.eks., flyttning mellom varme og kalde lokaler) Glatt underlag Utilstrekkelig belysning Andre faktorer, hva? _______________________________________________________


3

Analyse av resultater og førslag til tiltak Fyll i poengene (0, 1, 2) du fikk på hvert spørsmål i Tabell 1 i kolonne Poeng.I feltet Andre problemer angis bare den høyeste poengangivelsen fra delspørsmålene. Om det finns flere faktorer som fikk høyest poeng, rekker det med ett siffer. For analyse og tiltak sjekker man respektive spørsmål i sjekkelista. 1 poeng (små problemer) viser at det ikke er behov for tiltak nå. Derimot kan man iverksette tiltak i framtida når bedriften gjennomfører planlagte forbedringstiltak av arbeidsmiljø og rutiner som har til hensikt å forbedre arbeidsmiljøet. 2 poeng (store problemer) viser at forebyggende tiltak bør utføres snarest. Eksempel på tiltak finnes i separate dokument om "risikohåndtering i kulde".Fyll inn forslag på forebyggende tiltak i Tabell 1. Om problemene ikke går å at løse med enkle, tilgjenglige metoder, kryss av i feltet Behov for videre undersøkelser.Ved analyse og valg av tilltak skal man være seg bevisst at visse faktorer påvirker hverandre, f.eks. Kald luft samvirker med Vind/ luftbevegelser, Verneklær mot kulde og Beskyttelse mot kulde: hender, føtter, hode; Vann/ væsker/ fukt samvirker med Kontakt med kalde flater, Verneklær mot kulde osv. Disse faktorene til sammen kan øke risikoen. Diskuter med ledelsen hvilke tiltak som ska iverksettes. Bestem dato for neste observasjon for oppfølging av tiltak som skal iverksettes.

Tabell 1. Sammenfatning og analyse

Ska tiltak utføres

012

Ingen tiltak trengs Tiltak anbefales på lengre sikt Tiltak bør iverksettes snarest

Poen

g Forebyggende tiltak

Nei Ja

Behovfor

videreunder-

søkelser

Opp-følgings-

dato

1 Kald luft

2 Vind/ luftbevegelser

3 Kontakt med kalde flater

4 Vann/ væsker/ fukt

5 Beskyttelsesklær mot kulde

6 Beskyttelse mot kulde: hender, føtter, hode

7 Bruk av personlig verneutstyr (PPE)

8 Andre problemer

………………………… ………………… …………………… (Ansvarlig person) (Dato) (Godkjent)

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Copyright ©: Arbetsvetenskap, Luleå Tekniska Universitet, 971 87 Luleå Klimatgruppen, Arbetslivsinstitutet, 113 91 Stockholm

Checklista för att bedöma problem med kyla

Hur ska checklistan användas?

1. Skaffa en överblick över arbetsplatsen. Gör en grov uppdelning av de verksamheter som utförs dagligen och kommande tidsperiod. Använd en separat checklista för varje verksamhet. De verksamheter som ej kan observeras, kan bedömas senare. Om flera personer deltar i verksamhet, bedöm det värsta fallet.

2. Kolla igenom varje punkt i checklistan och fyll i det poängalternativ som stämmer bäst. 0 visar att läget är bra, 1 visar att det finns vissa problem, men de är inte akuta, 2 visar att finns problem som kan innebära risker vid arbete i kyla och som kan påverka arbetsresultat och hälsa - åtgärder bör snarast vidtagas.

3. Gör anmärkningar till varje punkt som har samband med den aktuella situationen (t.ex. arbetstagaren har dåligt skydd mot vind; man använder inga handskar alls; kroppsdel som är i kontakt med kalla ytor osv.). Sådana anmärkningar underlättar tolkningen av resultatet.

4. När ska checklistan användas? a) några gånger under vintersäsongen (en gång per månad); b) vid större förändring av de yttre förhållandena (klimat osv.); c) när arbetsuppgifterna förändras påtagligt; d) för att följa upp om vidtagna åtgärder har varit effektiva.

1

Checklista för att bedöma problem med kyla Företag/organisation:…....………………………....………………… Datum:……………...…………………....…………...Observerad verksamhet:……………...……………………………. Temperatur (om känd):……….……… °C

Vind (om känd):….…….….…………..… m/s

Poäng relateradetill problem: 0 Ingen åtgärd 1 Åtgärd rekommenderas 2 Bör åtgärdas

behövs på längre sikt snarast

1. Kall luft 0 Kylan orsakar inga problem1 Kylan orsakar vissa problem2 Kylan orsakar betydande problem

Anmärkningar:______________________________________________________________

2. Vind/ luftrörelse 0 Vindstilla1 Lätt luftrörelse (t.ex. dragkänsla, svag vind) 2 Stark luftrörelse (t.ex. stark vind blåser hela tiden eller då och då)

Anmärkningar:______________________________________________________________

3. Kontakt med kalla ytor vid hantering av verktyg/material eller vid sittande eller liggande på kalla ytor

0 Nästan aldrig1 Korta perioder av arbete med tunna handskar, sittande, knästående eller liggande på kalla ytor2 Arbete med bara händer, långa perioder av sittande, knästående eller liggande på kalla ytor

Anmärkningar:______________________________________________________________

4. Utsatt för vatten/ vätskor/ fukt0 Nej1 Korta perioder (några minuter, t.ex. hantering av våta material eller vid regn eller snö) 2 Långa perioder (t.ex. långvarig hantering av kalla vätskor/våta material osv.)

Anmärkningar:______________________________________________________________

5. Skyddskläder mot kyla (ej händer, fötter, huvud) 0 Tillräckliga1 Delvis otillräckliga (t.ex. bara vissa skyddskläder mot kyla används trots att det behövs) 2 Otillräckliga (t.ex. inga skyddskläder mot kyla används trots att det behövs)

Anmärkningar:______________________________________________________________


2

6. Skydd mot kyla: händer, fötter, huvud (bedöms i förhållande till det observerade klimatet; exemplen gäller främst skydd mot riktigt kalltklimat.

0 Tillräckligt (t.ex., tjocka vantar/handskar med tunna handskar inuti; vinterkängor med tjocka sulor och iläggs sulor; vindtät vintermössa som täcker öronen)

1 Delvis otillräckligt (t.ex., fodrade handskar; vinterkängor med tjocka sulor; skyddshjälmmed hjälmhuva eller icke vindtät mössa)

2 Otillräckligt (t.ex., ofodrade handskar eller inga handskar; skor med tunna sulor; baraskyddshjälm eller barhuvad) Anmärkningar:______________________________________________________________

7. Användning av personlig skyddsutrustning (PSU: hjälm, öronskydd,förkläde osv.)

0 Ingen olägenhet1 Viss olägenhet (t.ex. ökad klumpighet eller något begränsad rörlighet, sämre skydd mot kyla)2 Betydande olägenhet (t.ex. betydande problem att förena personlig skyddsutrustning med

skydd mot kyla; skydd mot kyla eller/och skyddsutrustning används inte alls) Anmärkningar:______________________________________________________________

8. Andra problem som har samband med kyla0 1 2

Lång vistelsetid i kyla Lätt arbete (t.ex. stående vid mätningsarbete, vakthållning vid vissa arbeten osv.) Varierande lätt och tungt arbete (t.ex. uppvärmning vid tungt och nerkylning vid lättarbete)Varierande omgivningsbetingelser (t.ex. flyttning mellan varma och kalla lokaler) HalkaOtillräcklig belysningAndra faktorer, vad? _______________________________________________________


3

Analys av resultat och åtgärdsförslag

Fyll i poängen (0, 1, 2) Du fick på varje fråga i Tabell 1 i kolumn Poäng.I fältet Andra problem fylls bara den högsta poängen i från alla delfrågor. Om det finns fler faktorer som fick högsta poäng, räcker det med en siffra. För analys och åtgärder kollar manrespektive frågor i checklistan. 1 poäng (små problem) visar att åtgärder inte behövs just nu. Däremot kan man åtgärda demi framtiden, när företaget/organisationen planerar förbättring av arbetsmiljö- och skyddsrelaterade rutiner. 2 poäng (stora problem) visar att förebyggande åtgärder bör utföras snarast. Exempel på åtgärder finns i separat dokument om "riskhantering i kyla".Fyll i förslag på förebyggande åtgärder i Tabell 1. Om problemen inte går att lösa med enkla, tillgängliga metoder, kryssa i fält Behov av vidare undersökning.Vid analys och val av åtgärder ska man vara medveten om att vissa faktorer påverkar varandra, t.ex. Kall luft samverkar med Vind/ luftrörelse, Skyddskläder mot kyla och Skyddmot kyla: händer, fötter, huvud; Vatten/ vätskor/ fukt samverkar med Kontakt med kalla ytor,Skyddskläder mot kyla osv. Dessa faktorer tillsammans kan öka risken. Diskutera med ledningen vilka åtgärder som ska vidtas. Bestäm datum för nästa observation för uppföljning av vidtagna åtgärder.

Tabell 1. Sammanfattning och analys

Utförande

01

2

Inga åtgärder behövsÅtgärder rekommenderas pålängre sikt Bör åtgärdas snarast

Poän

g Förebyggande åtgärder

Nej Ja

Behovav

vidareunder-sökning

Upp-följnings-

datum

1 Kall luft

2 Vind/ luftrörelse

3 Kontakt med kalla ytor

4 Vatten/ vätskor/ fukt

5 Skyddskläder mot kyla

6 Skydd mot kyla: händer, fötter, huvud

7 Användning av PSU

8 Andra problem

………………………… ………………… ……………………(Ansvarig person) (Datum) (Godkännande)Copyright ©: Arbetsvetenskap, Luleå Tekniska Universitet, 971 87 Luleå

Klimatgruppen, Arbetslivsinstitutet, 113 91 Stockholm

1

Evaluation of the usability of the checklist Please use a separate evaluation form for each observation/check

Observer’s name Observer’s education and occupation

1. How much time did you need to perform one observation?

Preparation: ___________________________________________min Realisation: ___________________________________________min Evaluation of the results: ___________________________________________min Further procedures: ___________________________________________minTotal: ___________________________________________min

2. To what extent did the nature of the observed work cause problems in the observation (i.e., was it difficult to observe the worker due to the content of the work, etc.)?

None It was a problem to some extent Considerable difficulties in performing an observation

If you had problems, what were they?___________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3. How adequate was the training to carry out the risk assessment procedure? It was easy to perform according to the given instructions It worked fairly well according to the given instructions, however some parts remained unclear (what:_____________________________________________) It was difficult to carry out the assessment according to the given instructions (why:____________________________________________________________)

4. How easy was it to use the checklist? It was easy to use The checklist requires rehearsing a few times The checklist requires extensive rehearsing

2

5. Who, according to your opinion, should conduct the risk assessment procedure in the future? Check the column besides the best fitting alternative.

Employee at the workplace Foreman at the workplace Occupational nurse Occupational physician Occupational safety expert Other, what: __________________________________

6. When (in what situations) should the checklist be used in the future? ___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

7. What are the limitations of the checklist? ___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

8. How do you think the checklist could be improved? ___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

Checklist evaluation sheet 1. How long did it take for you:

to make preparations for filling in the checklist?

to fill in the checklist?

to analyse the results (to fill in the summary table)?

to discuss and choose preventive measures?

less than 15 min 31–45 min more than an hour 16–30 min 46–60 min no preparations needed

less than 15 min 31–45 min more than an hour 16–30 min 46–60 min

less than 15 min 31–45 min more than an hour 16–30 min 46–60 min no analysis was done

less than 15 min 31–45 min more than an hour 16–30 min 46–60 min no discussion took place

2. Were the instructions that you received before starting the assessment procedure useful

when filling in the checklist?

when filling in the summary table

1 2 3 4 5 6 7 8 9 10

Not useful at all

Extremely useful

1 2 3 4 5 6 7 8 9 10

Not useful at all

Extremely useful

3. Was it easy (in terms of the structure and the way the questions were formulated) to fill in

the checklist?

the summary table?

1 2 3 4 5 6 7 8 9 10

Very very easy

Very very difficult

1 2 3 4 5 6 7 8 9 10

Very very easy

Very very difficult

4. In your opinion, how well are the structure and content of the checklist suited for identifying cold-related risk factors at the workplace?

1 2 3 4 5 6 7 8 9 10

Not at all Very well

5. In your opinion, who from the staff at your company should regularly carry out the cold risk assessment procedure?

the workers themselves a foreman the medical staff a work safety engineer someone else, who?____________________________________________________

APPENDIX II

Accepted for publication in: International Journal of Circumpolar Health

PAPER I

The field testing of an observational checklist for the assessment

of cold-related risk factors

Lina Giedraityt 1, Tiina M. Mäkinen2, Ingvar Holmér3 and Juhani Hassi2

1Division of Industrial Working Environment

Dept. of Human Work Sciences

Luleå University of Technology

S – 971 87 Luleå, Sweden

2Centre for Arctic Medicine

Thule Institute

University of Oulu

FIN – 90014 Finland

3 Climate Research Group

Dept. of Ergonomics

National Institute for Working Life

S – 112 79 Stockholm, Sweden

Short form of the title:

Checklist for assessment of cold-related risk factors

Lina Giedraityt ( )

Industriell Produktionsmiljö /Arbetsvetenskap

Luleå Tekniska Universitet

S - 971 87 Luleå, Sweden

Fax No: +46 920 491030

E–mail: [email protected]

mailto:[email protected]

1

ABSTRACT

There are very few methods available for the assessment of cold exposure and they rely more or less on complex equations for calculating heat balance; therefore, there is a need for new practical methods for the identification and control of cold hazards in workplaces. The aim of this study was to test a checklist which enables cold risk assessment based on observations in the workplace. The checklist has seven main sections of cold-related risk factors: cold air, wind/air movements, contact with cold surfaces, exposure to water/liquids/moisture, protective clothing against cold, protection of hands/feet/head from cold and the use of personal protective equipment. A total of 82 evaluation sheets were obtained from the field testing (24 from Sweden and 58 from Finland). The subjects found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment procedure, the interference of the method with the observed work, the adequacy of the instructions and the facility of the checklist.

KEYWORDS

Cold stress, cold-related risks, risk assessment, observational checklist

2

1 Introduction A structured approach to the identification, evaluation and control of work-related risks has to be adopted if good quality of the working practice of occupational health and safety (OH&S) is to be achieved (1). Employers having workers who operate in either indoor or outdoor cold environments have to evaluate cold risks among other risk factors arising in the workplace. The methods for the assessment of cold stress are presented in ISO technical report 11079 (2). The complementary information needed for the evaluation of cold stress can be found in other standards, such as ISO 8996 (3), ISO 9886 (4), ISO 9920 (5) and ISO 10551 (6). Holmér (7) has suggested an approach that might be used as a first assessment of the possible effects of exposure to cold based on these standards and other available scientific literature in the field.

However, available methods for the assessment of cold exposure are very few and rely more or less on complex equations for calculating heat balance (8); therefore, a certain level of expertise is needed for the successful application of these procedures. Such expertise may not be available to OH&S people, especially in small and medium-sized enterprises (SMEs). Furthermore, concerning the assessment of cold environments, there are no instructions for how to use the present ISO thermal standards in a complementary way in practical workplace assessments.

A recent field study (9) testing the usability of ISO thermal standards showed that there is a clear need for a new practical method to identify and control cold hazards in workplaces. Furthermore, it was found that the methods described in these standards were mostly useful in the more advanced stages (e.g. analysis) of cold risk assessment (9).

Malchaire, Gebhardt and Piette (10) expressed similar concerns regarding the use of ISO thermal standards for the evaluation of hot environments, questioning if such sophistication is needed for the first stage of any approach to the assessment of climatic conditions. They have proposed a strategy for the evaluation and prevention of risk due to work in thermal environments which rests on two basic principles: first, that it be participative and second, that it be structured in four stages – ‘Screening’, ‘Observation’, ‘Analysis’ and ‘Expertise’ – that require complementary knowledge and competence. The second stage, ‘Observation’, should provide a method for the identification of particular circumstances, specific tasks or certain working conditions where problems related to work in cold exist, as well as guidelines for the elimination of these problems. At the end of this stage the decision has to be made as to whether the problem is adequately controlled; and if not, then the third stage, ‘Analysis’ of the risk assessment has to be carried out with the help of occupational hygienists or persons with adequate training. If the problem still persists then the fourth stage, ‘Expertise’, has to be addressed (10).

The aim of this study was to test the usability of the developed observational checklist for cold risk assessment for use in the ‘Observation’ stage by workers themselves or by those responsible for work organisation who usually lack training in ergonomics or human factors.

2 Material and Methods

2.1 The development of the checklist The checklist was developed in a common effort by Finnish and Swedish research teams. It followed the recommendations for the ‘Observation’ method based on the results of validations carried out by 42 trained people in occupational health who worked primarily in SMEs and were confronted with climatic problems (10). According to these guidelines, a

3

checklist should be designed for use by people in industry (preferably by the workers themselves). It should be easy to understand even by untrained people (no references to concepts or technical terms), easy to use (the maximum required time no longer than one hour), based on simple observations (no measurements involved), oriented towards prevention and utilising the user’s knowledge of the workplace (10).

The relationship between climatic factors, i.e., low surface temperature, low air temperature and wind, and the anticipated cooling effects, i.e., whole body cooling and local cooling such as extremity cooling, airway cooling (or cooling of the respiratory tract), wind chill (or convective skin cooling) and contact cooling (or conductive skin cooling) is well known (11). Although the evaluation of the above named types of cold stress requires different sets of measurements, a quick estimate (for the purposes of the first rough classification of problems and/or the basis for further action, e.g., for a more detailed assessment or a preventive measure) may be based on information about the type and intensity of work, air temperature, wind speed and available personal protection (12).

The developed checklist (see annex 1) has seven main sections of cold-related risk factors: cold air, wind/air movements, contact with cold surfaces, exposure to water/liquids/moisture, protective clothing against cold, protection against cold: hands, feet and head and the use of personal protective equipment. Each of these seven sections has a choice of three levels (or ratings) for the risk factor and each level contains examples, facilitating the rating process. The following rating scale was applied: score 1 means that there is no need for preventive actions, score 2 indicates that corrective actions are recommended in the long term and score 3 denotes immediate need for corrective action. The same rating scale, although without examples for each level, applies to section 8 ‘Other problems related to work in cold’ that includes: long periods of time in cold, light work, variation between light and heavy work, variation of environmental conditions, slipperiness and insufficient lighting.

An important risk factor, low activity level or rate of work was not included in the seven main sections while two other categories, ‘Light work’ and ‘Variation between light and heavy work’ were added under section 8 instead. The likelihood of the appearance of one or more defined cold problems is very dependent on the combination of two variables: the temperature and the activity level (12), which makes it difficult to interpret. For example, to rate light work at the very risky activity level would not be right for temperatures above zero, whereas it would be true for low temperatures.

The checklist is accompanied by instructions on how and when to use the checklist and a summary table that helps to interpret the results. The instructions attached to the summary table give a more detailed explanation of the scoring scale, i.e. what to do if a certain score was chosen. Besides the score columns, the table has a column ‘A further investigation needed’ that has to be marked when the problem cannot be solved at this stage of risk assessment procedure and the third stage ‘Analysis’ has to be addressed. The other column ‘Preventive measures’ in the summary table is reserved for choosing the appropriate preventive measures.

2.2 Testing of the checklist

2.2.1 SubjectsIn Finland, four foremen filled in a checklist and a checklist evaluation sheet 31 times, three occupational nurses did it nine times and seven workers carried out the procedure 18 times. In the cases of the foremen and occupational nurses (except for the two nurses at the electrical installations company), the same person evaluated several working activities at the workplace

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on a single occasion using separate checklists and evaluation sheets for each observed activity. Therefore, the total number of the returned checklists and evaluation sheets is higher than the total number of the persons multiplied by the checklist testing occasions.

In the construction industry, the checklist was tested by two foremen and one occupational nurse at two worksites. The first foreman filled in the checklist and the checklist evaluation sheet nine times in total on five different occasions, while the second foreman did it nine times on four different occasions. The nurse repeated the procedure seven times on three different occasions.

Two companies represented the stevedoring and cargo handling industry. At one of these companies three workers tested the checklist and returned filled in evaluation forms seven times (one worker carried out the risk assessment procedure three times, while the other two did it twice each). At the other company two foremen (the first one did it nine times on four different occasions, the second repeated it four times on one occasion) and three workers (one worker tested the checklist two times and two workers did it three times each) conducted the cold risk assessment procedure. The stevedoring and cargo handling involved work (some of it was relatively light) conducted in cold and often windy conditions which may cause rapid body cooling. One characteristic problem area for this industry was that repair and maintenance work had to be conducted outdoors regardless of the ambient temperatures.

In the skiing and arctic golf centre, one worker tested the checklist and filled in the evaluation sheet three times. Two occupational nurses carried out the procedure once in a small company providing electrical installation services.

In Sweden, the checklist was tested at two construction companies, a road building company and a district office of the National Board of Forestry in the Northern part of Sweden. Both the workers (13) and the foremen (5) in these companies tested the risk assessment procedure. At the construction companies, two foremen filled in the checklist evaluation sheet after using the checklist for the second time, three workers filled it in after using the checklist for the first time and two workers filled it in twice, after using the checklist for both the first and second time. The construction workers in these companies carried out their activities in an unheated indoor and/or cold outdoor environment. Two fifteen minute coffee breaks and a one-hour lunch break allowed workers to warm up during the working day. The workers could stop their activities if they thought the temperature was too low to operate outdoors (usually if the temperature was below -25°C).

At the road building company, two foremen filled in the checklist evaluation sheet after using the checklist for the second time. The workers in the road building company were exposed to cold intermittently. They spent most of the day in the heated cabins of vehicles. The exposure to cold usually occurred when vehicle maintenance work was carried out during such activities as clearing the road of snow, gritting, etc.

In a district office for forestry, one foreman filled in the checklist evaluation sheet after using the checklist for the first time, three workers filled it in after using the checklist for the first time, one worker after conducting the procedure for the second time, two workers after doing it for both the first and second time, and two workers after testing the checklist for both the second and third time. The forestry workers usually spent about six hours out of an 8-hour working day outdoors. They spent one hour in the heated cabin (lunch and coffee breaks) and one hour for travel to and from the workplace by car and/or snow scooter. If the temperature was very low or it was very windy the workers would warm up in the heated cabins and take warm drinks every one or one and a half hour.

5

From this point, persons using the checklist and the checklist evaluation sheets are referred to as subjects representing the three above named groups (based on their occupation) of observers. Therefore the terms ‘observer’ and ‘subject’ are used interchangeably. In the case of foremen and occupational nurses, the observed work activity was carried out by someone else and not themselves, which was the case if the risk assessment procedure was performed by workers.

2.2.2 ProcedureThe study was carried out in the northern part of Finland and Sweden during December 2000 and April 2001. All the materials were prepared in English and later were translated into Finnish and Swedish. The training and testing of the checklists were conducted identically in each country.

The purpose of the study was explained to subjects who tested the usability of the checklist. After this the authors of the article together with the observer went through the instructions, the cold risk assessment checklist, the analysis table and the evaluation sheet. The observers were asked to perform the cold risk assessment procedure and to fill in the evaluation sheet for the checklist usability independently of the previous times, if any were already carried out. The subjects were also specifically asked to use a separate checklist evaluation sheet after each checklist was filled in. The observers themselves chose the time for conducting the risk assessment procedure. The assessment procedure was performed various times per subject. Each of the checklist tests was considered as independent from the others, although in the strict statistical definition they were not.

At the top of the checklist evaluation sheet the subject was asked to indicate his/her name and occupation. There was also a reminder that a separate evaluation form should be used for each observation.

The two-page checklist evaluation sheet addressed in a structured way the following: (1) the time needed to perform each stage of the risk assessment, (2) the interference of the method with the observed work, (3) the adequacy of the instructions, (4) the facility (i.e. ease of use) of the checklist and (5) who, according to the subject, should conduct the risk assessment at the workplace. At the end of the evaluation sheet, there were three questions on: (6) when (in what situations) the checklist should be used in the future, (7) what the limitations of the checklist were and (8) how the checklist could be improved. An empty space for answers was provided after each question.

In the question regarding the time needed to perform one observation in order to fill in the checklist the subjects were asked to indicate the time needed to perform each of the stages: preparation, realisation, evaluation of the results and further procedures, if any. As the subjects conducted the risk assessment procedures at times of their own choice, the authors had no possibility of controlling whether the indicated time in minutes was recorded accurately.

In the question whether it was difficult to observe the worker due to the content of the work, the observers had to choose one of three alternatives: (a) no, (b) it was a problem to some extent, and (c) there were considerable difficulties in performing an observation. Following the three alternatives was a question inviting the observer to describe any encountered problems.

In the third question on the adequacy of training, the subjects had to check one of the boxes indicating whether (a) it was easy to perform the risk assessment procedure according to the given instructions, (b) it worked fairly well according to the given instructions, however some

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parts remained unclear, or (c) it was difficult to carry out the assessment according to the given instructions. Alternatives (b) and (c) were followed by the short questions ‘what’ and ‘why’, respectively, along with empty spaces for providing the answers.

In the fourth question on how easy it was to use the checklist, the three alternatives were (a) it was easy to use, (b) the checklist requires rehearsing a few times, and (c) the checklist requires extensive rehearsing.

In the last structured question which inquired who, according to the subject, should conduct the risk assessment procedure in the future, the subjects were asked to check the box beside the best fitting alternative whether it be an (a) employee at the workplace, (b) foreman at workplace, (c) occupational nurse, (d) occupational physician, (e) occupational safety expert or (f) other. In the case of the latter there was a short ‘who’ encouraging the subject to name the occupation of the suitable person.

2.2.3 Statistical analysis In order to conduct statistical analysis on the time needed to conduct the risk assessment procedure, each checklist evaluation sheet had to satisfy the criterion of having a time indication for each of the three stages: preparation, realisation and evaluation of the results. Thus answer sheets with a missing time indication for at least one of these stages were excluded from further analysis.

As the accuracy of time data could not be verified by the authors, it was treated as nominal data. The time indications for each stage and the total time for the whole procedure given in minutes were converted into four categories based on percentile groups. A value of 1 was assigned to cases below the 25th percentile, the value 2 was given to cases between the 25th

and 50th percentile, the value 3 was given to cases between the 50th and 75th percentile, and the value 4 was assigned to cases above the 75th percentile.

The standard statistical package SPSS was used to analyse the data by an independent samples Mann-Whitney U test to compare the results from Finnish and Swedish groups. In order to determine whether the different answer alternatives were chosen at a greater-than-chance-level, Pearson’s approximation to chi-square test ( 2) for one way classification was applied to the data at the significance level =.05.

3 ResultsA total of 82 checklist evaluation sheets (24 from Sweden and 58 from Finland) were obtained from 32 different observers. The total time (in the further analysis) was calculated as a sum of the three stages: preparation, realisation and evaluation of the results. The statistical analysis was applied to a sample size of N=70 evaluation sheets (or N=49 in the Finnish, and N=21 in the Swedish group).

The Mann-Whitney U-test returned a statistically significant result on the total time (for preparation, realisation and evaluation of the results stages together) needed to conduct cold risk assessment using the checklist when the Finnish and Swedish groups were compared (Mann-Whitney U=341, =.020, two-tailed). The same test performed on the times needed to carry out each of the stages by Finnish and Swedish groups yielded a statistically significant result only for the preparation stage (Mann-Whitney U=274.5, =.001, two-tailed).

As there were no differences in times needed to carry out the realisation and evaluation of the results stages of the cold risk assessment procedure between the Finnish and Swedish groups, the mode for each stage was calculated for both groups together. The most commonly

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appearing category for the realisation stage was the one denoting ten minutes, and for the evaluation of the results stage the one denominating five minutes.

According to the time indications provided in the evaluation sheets returned by the Finnish observers, the most commonly occurring category describing the time needed for the preparation stage was the one marking five minutes. From the Swedish evaluation sheets, the most commonly occurring category for the same stage was the one corresponding to ten minutes. In the evaluation sheets filled in by the Finnish observers the most commonly occurring category for the total time needed to conduct cold risk assessment procedure was the one with the time denomination of 20 minutes. Similarly, in the Swedish evaluation sheets the most commonly occurring category denoted times of 22, 25 and 30 minutes.

There were several evaluation sheets that lacked information to some of the questions discussed below; therefore the number of evaluation sheets with valid data varied from 74 to 80 depending on the question.

According to the majority of the answers in the checklist evaluation sheets (N=72 or 95%), the observational checklist did not interfere with the observed work activities. The remaining 5% (N=4) of the answers indicated that the subjects faced this problem to some extent. There were no evaluation sheets implying that the observers experienced considerable difficulties in performing the cold risk assessment procedure with the help of the observational checklist. The Mann-Whitney U test found no statistically significant differences between the answers in the evaluation sheets provided by the Finnish (N=56 evaluation sheets) and Swedish (N=20 evaluation sheets) groups. After pooling the Finnish and Swedish groups together, Pearson’s

2 (df=1, N=76) =60.84 showed that there was more variability among the frequencies of chosen answer alternatives than would be expected by chance.

According to the answers in 92% of the evaluation sheets (N=73), the observers could perform the risk assessment procedure easily based on the given instructions. In the remaining 8% of the evaluation sheets (N=6) it was indicated that the subjects were still unclear on some parts after reading the instructions. None of the evaluation sheets suggested that the subjects had difficulties to perform the procedure according to the instructions. The Mann-Whitney U yielded statistically insignificant results when answers from the Finnish (N=56) and Swedish (N=23) groups were compared. The Pearson’s 2 (df=1, N=76) =56.82 statistic obtained from the combined answers from the Finnish and Swedish observers produced a significant result indicating that answer categories were chosen at frequencies different from those defined by chance.

In the majority of the evaluation sheets (N=66 or 82.5%) the subjects claimed that they found it easy to use the checklist. In the remaining 17.5 % of the evaluation sheets (N=14) it was indicated that it was necessary to rehearse the checklist a few times. None of the evaluation sheets indicated that extensive rehearsal was required. The groups of Finnish (N=56) and Swedish (N=24) observers had experienced the facility of the checklist differently (Mann-Whitney U=544, =.04, two-tailed). The absolute majority of the answers received from the Swedish group (N=23 evaluation sheets or 96%) claimed that it was easy to use the checklist. The corresponding result for the Finnish group of observers was provided in N=43 evaluation sheets or 78%. The Pearson’s 2 statistics performed on the Finnish (df=1, N=56) =16.08 and Swedish (df=1, N=24) =20.17 groups separately showed that the different answer alternatives in each group were chosen at a greater-than-chance-level.

The observers could choose more than one of several alternatives while answering the question regarding who they felt should conduct the cold risk assessment at the workplace. The subjects returned 74 evaluation sheets that had answers to this question: 55 evaluation sheets were filled in by Finnish subjects and 19 by Swedish observers. There were 49

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evaluation sheets that had indicated one alternative (34 Finnish, 15 Swedish), 21 evaluation sheets had indicated two alternatives (20 Finnish, 1 Swedish) and four sheets had indicated three alternatives (1 Finnish, 3 Swedish). In total, 103 alternatives (77 Finnish, 26 Swedish) were indicated in the evaluation sheets. The alternatives marked in the evaluation sheets returned by Finnish and Swedish observers varied (Mann-Whitney U=457, =.001, two-tailed). In the Finnish group, the observers most often indicated that someone else rather than those originally mentioned in the evaluation sheet (in 34 cases or 44%) and a foreman at workplace (in 29 cases or 38%) should carry out the risk assessment procedure. The Swedish observers thought that the one assessing cold risks at the workplace should be an employee at workplaces (mentioned in 14 evaluation sheets or 54%) and a foreman (mentioned in 7 evaluation sheets or 27%). Among those suggested for conducting cold risk assessment at the workplace by the Finnish observers, a workers’ representative responsible for industrial safety at the workplace was mentioned most often.

4 Discussion The results of testing the observational checklist showed that it complies well with the recommendations given by Malchaire et al. (10) for the ‘Observation’ method. According to the field testing results, the developed checklist is an observational method that does not require comprehensive training or knowledge in the assessment of thermal environments, and it causes no interference with the observed work activities. The majority of the observers could easily conduct the risk assessment procedure according to the instructions they had received and found it easy to use the observational checklist. Although there was a difference in the experienced checklist facility between the Finnish and Swedish groups, the majority of the evaluation sheets in each of group indicated that it was easy to use the checklist.

Furthermore, the persons who should be performing the cold risk assessments, as suggested by the observers, are the ones who are very well versed in the content of the work. According to the Finnish observers, a workers’ representative responsible for industrial safety and workers themselves should carry out the assessment procedure. This approach was supported by the answers in the Swedish evaluation sheets where workers at the workplace were mentioned most often.

According to Malchaire et al. (10), the maximum time required to perform the risk assessment procedure on the ‘Observation’ level should be no longer than one hour. After applying stricter requirements to the data and reducing the sample size to 70 evaluation sheets, there were only two evaluation sheets where it was indicated that observers needed longer than one hour (a time of 75 minutes was indicated in one Finnish evaluation sheet and 105 minutes was indicated in one Swedish evaluation) to perform the risk assessment procedure. Based on the results, it can be concluded that the expected time for carrying out the cold risk assessment procedure at a workplace is between 20 and 30 minutes.

The statistically significant difference between the times taken to perform the whole risk assessment procedure by the Swedish and Finnish groups could have resulted from the significant differences in time taken to perform the preparation stage. A possible explanation for the differences in time needed to conduct the preparation stage is the fact that information was presented to the groups in different languages (although the content of the written information was identical) and that different groups of the authors had trained the observers.

The time to perform a risk assessment procedure would probably be longer if the stage of ‘Further procedures’ were included in the calculation of the total time. However, only 44% of the answer sheets had times indicated for this stage. Furthermore, there was no clear understanding among observers about what the further procedures should include (for

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example, some of them included the travel time to and from the observed worksite). Therefore, the total time was a sum of only three stages. On the other hand, the fact that the observers received training and instructions in person could have shortened the time needed to perform the risk assessment procedure. Another factor that might have reduced the time needed to perform the procedure is the fact that individual observers had tested the checklist and filled in the evaluation sheets several times (on average approximately 2.5 evaluation sheets per observer). However, the study design is such that it does not allow verifying the hypothesis of whether a learning effect made a difference in the time needed to conduct the cold risk assessment procedure after the checklists was used for the first, second or third time.

The main purpose of the risk assessment within occupational health and safety (OH&S) is to determine whether the planned or existing measures in the company control policy are adequate (1). The checklist encourages taking preventive measures if the problem is slight or serious, and a special space for this purpose is reserved in the summary table. Furthermore, a column for the follow-up date of the implemented preventive measures is included in the summary table in order to promote a continuous cold risk assessment.

The developed checklist can be easily integrated in the cold risk management model for companies developed by Risikko et al. (13). The model provides tools, such as a cold risk management plan for the workplace, to plan and carry out various preventive measures against cold hazards at the workplace.

Regardless, the used observational checklist only indicates potential areas where problems may arise (for results see (14)). If a more accurate and reliable assessment of cold risks is required, a systematic collection of data relevant to the expected risks should be performed. The types of cold stress and the appropriate measurements for their assessment can be found in various human factors handbooks or in ergonomics journal articles such as the one by Holmér (12).

In conclusion, the subjects found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment, the interference of the method with the observed work, the adequacy of the instructions and the facility of the checklist.

AcknowledgmentsThis study was supported by the European Regional Development Fund (Barents Interreg IIA Program). We would like to thank all of the observers who participated in the study. Our thanks also go to research engineers Anita Hicks and Tanja Risikko, educational trainer Liisa Hänninen and trainer Maire Huurre from the Cold Work Action Program of the Finnish Institute of Occupational Health, Finland; professor John Abeysekera from Luleå University of Technology, Sweden; dr. Kalev Kuklane from the National Institute for Working Life, Sweden; managing director Arvid Påsche and senior engineer Bård Holand from Thelma AS, Norway for their contributions to the study.

Literature:1. BS 8800 Guide to occupational health and safety management systems. British Standards

Institution, London, 1996. 2. ISO/TR 11079 Evaluation of cold environments – Determination of required clothing

insulation (IREQ). International Organisation for Standardisation, Geneva. 1993.

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3. ISO 8996 Ergonomics – Determination of metabolic heat production. International Organisation for Standardisation, Geneva. 1990.

4. ISO 9886 Evaluation of thermal strain by physiological measurements. International Organisation for Standardisation, Geneva. 1992.

5. ISO 9920 Ergonomics of the thermal environment – Estimation of the thermal insulation and evaporative resistance of a clothing ensemble. International Organisation for Standardisation, Geneva. 1995.

6. ISO 10551 Ergonomics of the thermal environment – Assessment of the influence of the thermal environment using subjective judgement scales. International Organisation for Standardisation, Geneva. 1995.

7. Holmér I. Risk assessment in cold environment. Barents Newsletter on Occupational Health and Safety 1999; 1(3): 77–79.

8. Holmér I. Assessment of cold stress. Arctic Medical Research 1991; 50(Suppl. 6): 83–88. 9. Mäkinen T, Hassi J. Usability of ISO thermal standards for cold risk assessment in the

workplace. Int J Circumpolar Health 2002; 61(2): 142–153. 10. Malchaire J, Gebhardt HJ, Piette A. Strategy for evaluation and prevention of risks due to

work in thermal environments. Ann Occup Hyg 1999; 43(5): 367–376. 11. Holmér I. Cold indices and standards. In: Stellman JM, ed. Encyclopaedia of

occupational health and safety. Geneva: ILO 1998; 4248–4255. 12. Holmér I. Cold stress: Part I – Guidelines for the practitioner. Int J Industrial Ergonomics

1994; 14(1–2): 139–149. 13. Risikko T, Mäkinen T, Påsche A, Toivonen L, Hassi. J. A model for managing cold-

related health and safety risks at workplaces. Int J Circumpolar Health 2003; 62(2): 204–215.

14. Giedraityt L, Mäkinen T, Abeysekera J, Holmér I, Hassi J. Observed cold-related risk factors for indoor and outdoor work in the Nordic countries and north-western Russia. Manuscript submitted to Int J Industrial Ergonomics 2005.

ANNEX 1 A checklist for identifying cold-related problems at work

How to use the checklist?

1. Consider the working environment as a whole. Before using the checklist, go through the different activities to be observed and categorise the prevailing working situation to include all the circumstances that are likely to arise during a day and for a foreseeable period of time. Then apply the checklist separately to each activity. If it is not possible to consider all the separate tasks involved in the work, apply the checklist later. If several employees are engaged in the same work, apply the checklist to the individual who in your opinion has the most problems in the cold.

2. Check through each condition/category separately and indicate the score that corresponds best to the situation. The score 0 implies that no preventive actions are needed, 1 that certain cold-related problems exist and should be dealt with in the long term, and 2 that there are cold-related problems which may involve a risk of impaired health and performance and that corrective action should be taken immediately to reduce or eliminate the problem.

3. Add remarks or more precise observations on each condition, e.g. that the worker is poorly protected against the wind, that gloves are not used at all etc. These remarks will be of help when the results are interpreted.

4. When should the checklist be applied? a) a few times during the winter (once a month and/or if environmental

conditions change) b) when the nature of the work alters substantially c) when the working environment alters substantially d) after new preventive measures have been introduced

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This checklist was produced in a project supported by the European Regional Development Fund (Barents Interreg IIA Programme)

Checklist for the identification of cold-related problems Name of company:…....………………………....………………………………....… Date:……………....………………………………………....…

Working activity observed:…....…………………………………………....… Temperature (if known)....…………… °CWind (if known) ....…………………………… m/s

Scoring:0 No need for 1 Corrective actions 2 Immediate need preventive are recommended for corrective actions in the long term action

1. Cold air 0 Air temperature does not cause any problem 1 Air temperature causes certain problems 2 Air temperature causes obvious problems

Remarks:______________________________________________________________________

2. Wind/air movements 0 No air movement 1 Light air movement (e.g. sensation of draught, light wind) 2 Pronounced air movement (e.g. strong wind blowing occasionally or repeatedly)

Remarks:______________________________________________________________________

3. Contact with cold surfaces while handling tools/materials, or sitting, kneeling or lying on cold surfaces

0 Not at all 1 Working for short periods with thin gloves, sitting, kneeling or lying on cold surfaces 2 Working with bare hands or for longer periods sitting, kneeling, standing or lying on cold

surfaces

Remarks:______________________________________________________________________

4. Exposure to water/liquids/damp 0 No exposure 1 Short periods of exposure (e.g. when handling cold materials, working in rain or snow etc.) 2 Long periods of exposure (e.g. continuously handling cold fluids or wet materials etc.)

Remarks:______________________________________________________________________

5. Protective clothing against the cold (excluding the hands, feet and head) 0 Sufficient 1 Partly insufficient (e.g. only some winter clothing in use) 2 Insufficient (e.g. no protective clothing used although needed)

Remarks:______________________________________________________________________

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6. Protection against the cold: hands, feet, head (estimated in relation to the prevailing conditions). The examples in parenthesis represent mainly protection against very cold weather.

0 Sufficient (e.g. inner gloves and mittens, winter boots with thick soles and loose insoles, windproof winter hat covering the ears) 1 Fairly good (e.g. gloves with a lining, winter shoes with thick soles, a safety helmet with

inner cap or a non-windproof hat) 2 Insufficient (e.g. gloves without a lining, no gloves, shoes with thin soles, a safety

helmet without an inner cap, or no hat)

Remarks:______________________________________________________________________

7. Use of personal protective equipment (helmet, hearing protection, etc.)0 No interference with work 1 Interferes with work to some extent (e.g. clumsiness, restricted movements, impaired

protection against the cold)2 Considerable interference (e.g. considerable difficulties in combining cold protective

clothing and use of PPE, or cold protective clothing/PPE not used at all)

Remarks:______________________________________________________________________

8. Other cold-related problems 0 1 2

Long-term cold exposure/working in the cold (e.g. continuously >2 hrs) Light work (e.g. standing while measuring, monitoring etc.) Highly varying workload (light/heavy) Varying thermal environments (e.g. frequent moving between indoor and outdoor

conditions) Slipperiness Insufficient lighting Other factors, what? ______________________________________________________

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Evaluation of the results of the checklist and selection of corrective actions

Transfer the scores for the separate items (0, 1, 2) to the column scoring in Table 1.For the item Other problems, fill in the highest score observed. If several of the activities checked have gained the highest score, only one score is filled in. Each of these activities can be considered separately when evaluating the results and selecting preventive measures. A score of 1 indicates that no preventive measures are needed just now, but that improvements should be made in the company’s OHS system to improve the workers’ health and safety in the cold. A score of 2 indicates that preventive measures are needed immediately to reduce or eliminate adverse effects of cold conditions. Propose a suitable preventive measure in Table 1. If the problem cannot be solved by simple management methods, place a cross in the column Need for further analysis When evaluating the results and choosing the preventive measures one should be aware that there may be interaction between some of the factors. For example, cold air interactswith wind/air movements, similarly cold protective clothing with protection of the extremities, and water/liquids/damp with touching of cold materials and cold protective clothing etc. These interactions may aggravate the cold risk. Discuss the protective measures to be implemented with the management of the company. Set a date for re-check to assess the adequacy of the measures.

Table 1: Summary of results and selected preventive measures

Imple-mentation

01

2

No need for corrective actionCorrective action needed in the long term Corrective action needed immediately Sc

orin

g

Preventive measures

No Yes

Need for Further Analysis

Date of Re-check

1 Cold air

2 Wind/air movement

3 Touching cold surfaces

4 Water/liquids/wetness

5 Protective clothing

6 Protection against cold: hands, head, feet

7 Use of PPEs

8 Other problems

………………………… ………………… …………………… (Responsible person) (Date) (Approved)

Submitted to: International Journal of Industrial Ergonomics

PAPER II

The usability of an observational checklist for the assessment of

cold-related risk factors tested by Russian sawmill workers

Lina Giedraityt , Petr N. Rybitski and Nadejda Loukianova

Lina Giedraityt ( )

Division of Industrial Working Environment

Department of Human Work Sciences


971 87 Luleå, Sweden

Fax No: +46 920 491030


Petr N. Rybitski and Nadejda Loukianova

Division of Furniture and Design

Dept. Mechanical Technology of Wood

Archangelsk State Technical University

Northern Dvina emb., 17

Archangelsk, 163002, Russia


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ABSTRACT

The checklist which enables cold risk assessment based on observations in the workplace by evaluating 13 cold-related risk factors was previously tested in Finland and Sweden. The aim of this study was to test the checklist at workplaces in a country representing a different approach to safety culture than the one prevailing in Scandinavian countries. A secondary objective was to test whether there was a learning effect reflected in the results recorded in the evaluation sheets when filled in after conducting the cold risk assessment procedure for the first, second and third time. A total of 277 evaluation sheets were obtained from 116 observers from two sawmills in north-western Russia. The observers, similarly to the ones in Finland and Sweden, found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment procedure; the instructions provided for the checklist and to the summary table; the facility of the checklist and summary table and the suitability of the checklist (in regards to the structure and content) in identify cold-related risk factors. According to the Nordic observers, a workers’ representative responsible for industrial safety and the workers themselves should carry out the assessment procedure at the workplace. On the contrary, the Russian observers mentioned workers only in 7.5% of the evaluation sheets, giving priority to a safety engineer (mentioned in 50.5% of evaluation sheets) and a foreman (mentioned in 22.6% of evaluation sheets). No statistically significant effects of learning were found when three groups of answers (after the first, second and third time) from 73 observers were compared.

RELEVANCE TO INSDUSTRY

Simple and usable methods for screening occupational cold problems are needed in workplaces with cold exposure.

KEYWORDS

Cold stress, Cold-related risks, Risk assessment, Observational checklist, Safety culture

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1 Introduction Various assessment tools based on direct observations are widely use in the field of ergonomics. In a study of the survey tools used by certified professional ergonomists, 70.5% of 301 respondents indicated using checklists in their practice (Dempsey et al, 2005). However, the majority of them are developed in the western world reflecting the western approach to safety culture.

Traditionally in the western world, attempts to improve safety in the workplace have been addressed via legislation, engineering solutions or safety training. In recent years, the ways to improve workplace safety have focused on the concept of an identifiable safety culture (Cooper, 1998). The author lists among others the following organisational characteristics of a good safety culture: accepting that the promotion of a safety culture is a long term strategy which requires sustained effort and interest; adopting a formal health and safety policy, supported by adequate codes of practice and safety standards; and stressing that health and safety is equal to other business objectives.

In European Union countries, the proactive management of safety is promoted rather than the inspection of sites/premises. This is a result of recent directives, such as Directive 89/391/EEC on the introduction of measures to encourage improvements in the safety and health of workers at work (Council of the European Communities, 1989). The employers are now required to take steps to identify and manage hazards by undertaking formal assessments of risks (BS 8800, 1996). Thereafter they must plan, organise, implement, control, monitor and review preventive measures.

In Russia and other countries of the Commonwealth of Independent States (the majority of former USSR countries), there is an amazing gap between theory and practice in the field of assuring labour safety and improving working conditions due to four sets of reasons: scientific, engineering, economic and social (Munipov, 1993). According to the author, the dominating technocratic approach to designing and engineering equipment and systems considers humans as being merely supplementary to them. As to economic reasons, the existing centralised procedure of privileges and compensations to those working under unhealthy conditions encourages the employers to preserve such labour conditions so that higher wages are insured for the employees.

A checklist which enables cold risk assessment based on observations in the workplace by evaluating 13 cold-related risk factors was previously tested in Finland and Sweden (Giedraityt et al., 2005). The subjects found the observational checklist to be a usable tool for cold risk assessment in terms of the time needed to perform the risk assessment, the interference of the method with the observed work, the adequacy of the instructions and the facility of the checklist.

The aim of this study was to test the checklist at workplaces in a country representing a different approach to safety culture than the one prevailing in Scandinavian countries. A secondary objective was to test whether there was a learning effect reflected in the results recorded in the evaluation sheets when filled in after conducting the cold risk assessment procedure for the first, second and third time.


2.1 SubjectsThe cold-related risk factors were observed 277 times at two sawmills by nine foremen (27 checklists were filled in) and 105 workers (250 checklists). Only the workers that were

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currently working outdoors on the day when the authors visited the two sawmills for the first and second time were asked to volunteer for the study. In the original study design it was intended that all observers should conduct the risk assessment procedure three times; therefore it was not possible for additional workers to join the study on a later occasion. However, some of the observers dropped out and only 88 of 116 volunteers filled in the checklist twice and only 73 of them did it three times.

In the first sawmill, there were about 1.500 employees, roughly 1.300 of which were directly involved in the production. The safety engineer at the company could only provide an estimate for the number of people working outdoors of around 500. In the second sawmill, there were approximately 2.300 employees, around 950 of which were outdoor workers. Both sawmills worked on a three-shift regime. Roughly half of the employees were women; whereas it is unusual to find so many women working at sawmills in the western world. The cold risks were observed for outdoor work activities such as inspecting the delivered logs, sorting and marking both the floating logs and the processed timber. The working conditions were especially harsh for those working at a basin where the logs were sorted. Even if the workers had scheduled warm breaks, the management at one of the companies decided to cancel the breaks so that the lorries delivering the logs would not have to wait in a queue. The ambient temperature was around –30°C that night and the night shift workers were not supposed to take breaks during the entire shift.

2.2 ProcedureThe study was carried out in the region of Archangelsk, north-western Russia, from December 2003 until March 2004. An observational checklist for the assessment of cold-related risk factors (Giedraityt et al., 2005) was used to rate 13 risk factors: ‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’, ‘protective clothing against cold’, ‘protection of extremities against cold’, ‘use of personal protective equipment (PPE)’, ‘long-term cold exposure’, ‘light work’, ‘highly varying workload’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’.

The purpose of the study was explained to observers who tested the usability of the above named checklist. After this the authors of the article together with the observers went through the instructions, the cold risk assessment checklist, the analysis table and the evaluation sheet. The observers were asked to perform the cold risk assessment procedure and to fill in the evaluation sheet for the checklist usability independently of the previous times, if any were already carried out. The observers were also specifically asked to use a separate checklist evaluation sheet after each checklist was filled in. The observers themselves chose the time for conducting the risk assessment procedure. The cold risk assessment and the checklist evaluation procedure were performed either once, twice or three times per observer.

The one-page checklist evaluation sheet was attached to the checklist. It addressed in a structured way the following: (1) the time needed to perform each stage of the risk assessment procedure, (2) the instructions provided for the checklist and summary table, (3) the facility of the checklist and summary table, (4) the suitability of the checklist in terms of structure and content for identifying the cold-related risk factors and (5) who, according to the observer, should conduct the risk assessment at the workplace.

In the question regarding the time needed to perform one observation in order to fill in the checklist, the observers were asked to indicate the time it took them to perform each of four stages: preparation, realisation, evaluation of the results and discussion of the results, if any. The observers had to check the box indicating one of the following alternatives: (a) less than 15 min, (b) 16–30 min, (c) 31–45 min, (d) 46–60 min (e) more than an hour and (f) either no

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preparations needed (for the preparation stage), or no analysis was done (for the evaluation stage) or no discussion took place (for the stage of discussion of possible preventive measures, if needed). There was no alternative (f) for the realisation stage.

In the second question on the usefulness of the instructions, the observers were asked to mark separately on the scale from 1 (not useful at all) to 10 (extremely useful) how useful the instructions were for filling in the checklist and the summary table. The same scale with different denominations for the scores 1 (very very easy) to 10 (very very difficult) was used to separately evaluate the facility of the checklist and the summary table. The scale from 1 (not at all) to 10 (very well) was also used to appraise the suitability of the checklist (in terms of structure and content) for identifying cold-related risk factors at the workplace.

In the fifth question which inquired who, according to the observer, should conduct the risk assessment procedure in the future, the observers were asked to check the box beside the best fitting alternative whether it be (a) the workers themselves, (b) a foreman, (c) the medical staff, (d) a work safety engineer, or (e) other. In the case of the latter there was a short ‘who’ encouraging the observer to name the occupation of the suitable person. The observers could choose more than one alternative to answer this question.

2.3 Data analysis

The standard statistical package SPSS was used to analyse the data by Friedman’s two way analysis of variance of ranks for related samples, Wilcoxon matched-pairs signed-ranks test, Kruskal-Wallis H one way analysis of variance for independent samples and independent samples Mann-Whitney U test. In order to avoid the problem of inflated error rates and to limit the study-wide Type I error at =.05 level, the Bonferroni adjustment technique was used resulting in =.05/3=.017 level per comparison when grouped data were compared pairwise. In order to determine whether the different answer alternatives were chosen at a greater-than-chance-level, Pearson’s approximation to chi-square test ( 2) for one way classification was applied to the data at the significance level =.05.

In order to see whether the learning factor had any effects on the ratings, an analysis was carried out on the evaluation sheets returned from the 73 observers who had completed the risk assessment procedure three times. The three groups, each containing the same amount of ratings (N=73), were treated by Friedman’s two way analysis of variance and the Wilcoxon matched-pairs signed-ranks test of ranks for related samples. Later on in the analysis, in order to compare the three extended groups, the Kruskal-Wallis H test was employed, followed by the Mann-Whitney U test (whenever appropriate), assuming that three groups represented independent samples.

3 ResultsThe total of 277 received evaluation forms were divided into three groups. The first group consisted of the evaluation sheets (N=116) filled in after carrying out the cold risks assessment procedure for the first time, the second group comprised the evaluation sheets (N= 88) filled in after conducting the procedure for the second time while the third group consisted of evaluation sheets (N=73) filled in after using the checklists for the third time.

According to the results of Friedman’s two-way ANOVA, there were no differences in the scores that the observers (N=73) assigned after they had performed the risk assessment procedure for the first, second and third time for any of the five questions: whether the given instructions helped to fill in the checklist; whether the given instructions helped to fill in the summary table; whether it was easy to fill in the checklist; and whether it was easy to fill in

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the summary table and whether the checklist was suited for identifying cold-related risk factors at the workplace.

According to the results of Friedman’s two-way ANOVA, there were no statistically significant differences between the time categories indicated by observers (N=73) after conducting the cold risk assessment procedure for the first, second and third time for the following stages: preparation, realisation and analysis of results. It returned a statistically significant result for the time that was needed to discuss the results and to choose the preventive measures after filling in the checklist for the first, second and third time (Friedman’s 2=20.59, df=2, N=73, p=.000). The Wilcoxon matched-pairs signed-ranks test returned statistically significant results for each pair: the second time group versus the first time group (Wilcoxon T+ was –2.78, N=73, p=.005), the third time group versus the first time group (Wilcoxon T+ was –4.66, N=73, p=.000) and the third time group versus the second time group (Wilcoxon T+ was –2.55, N=73, p=.011). The mode for the group of evaluation sheets filled in after using the checklist for the first time was category ‘no preparations nedded’ (indicated in 49.3% of the evaluation sheets). The mode for the other two groups (after the second time and after the third time) was category ’less than 15 minutes’ with respective frequencies of 91.8% and 82.2%.

As no learning effects were detected, the evaluation sheets from the observers that conducted the cold risk assessment procedure only once or twice were included in the corresponding group. Therefore there were 116 evaluation sheets in the first time group, 88 sheets in the second time group and 73 sheets in the third time group. In order to compare these extended groups the Kruskal-Wallis H test was employed, assuming that the three groups represented independent samples. There were no statistically significant differences between the three groups of ratings for any of the five questions nor the time categories chosen for the stages of preparation and analysis of results. Statistically significant differences were found for the time needed to fill in the checklists, as indicated by the observers after they assessed cold risks for the first, second and third time (Kruskal-Wallis’ 2=6.75, df=2, N=277, p=.034). The Mann-Whitney U test found no statistically significant differences when the groups were compared in pairs at =.017 after applying the Bonferroni’s technique.

The modes of the ratings for each of the questions and for the categories of times needed to perform a certain stage of the risk assessment procedure were calculated from the answers in 277 checklists. The mode of the ratings on the usefulness of instructions for filling in both the checklist and the summary table was 10 (median 6). The score corresponding to the mode was marked in 23.1% of the evaluation sheets when the usefulness of instructions for filling in the checklist was rated; and in 23.8% of the sheets when the usefulness of instructions for filling in the summary table was rated. The mode of the ratings for the facility of both the checklist and the summary was 1 (median 3). The score corresponding to the mode was marked in 33.6% of the evaluation sheets for the question regarding the facility of the checklist and in 35.7% of the sheets for the question regarding the facility of the summary table. The mode of the ratings obtained for the question whether the observers considered the developed checklist to be a suitable tool to investigate the cold related problems was 10 (median 7). The score corresponding to the mode was selected in 24.9% of the evaluation sheets.

The Pearson’s approximation to chi-square test ( 2) for one way classification returned a statically significant result for the frequencies of chosen categories for each of the three stages of the risk assessment procedure. The most often selected category for the time needed to make preparations in order to fill in the checklists was the one denoting a time of ‘less than 15 min’ (in 84.8% of the evaluation sheets). The same category was also most often marked for the time needed to fill in the checklists (in 89.2% of evaluation sheets) and for the time

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needed to analyse the results (in 94.9% of evaluation sheets). The median of the times needed to perform each of these three stages was also 1.

The observers could indicate several alternatives for who they thought should regularly carry out the cold risk assessment procedures at their workplaces. For statistical reason, only those observers (among the 73 who conducted the cold risk assessment procedure three times) were chosen who indicated only one alternative all three times (N=43). The Friedman’s two-way ANOVA test found no statistically significant differences between the chosen alternatives after the checklists were filled for the first, second and third time.

There were 372 alternatives marked for those best suited to conduct the risk assessment procedure in the 277 evaluation sheets returned. In 218 evaluation sheets (or 78.7%) there was one alternative marked, in 34 sheets (or 12.9%) there were two alternatives marked, in 19 sheets (or 6.9%) there were three alternatives marked, in four sheets there were four alternatives marked and in two sheets there were all five alternatives marked. According to the observers, a work safety engineer should conduct the risk assessment at the workplace (mentioned in 50.5% of evaluation sheets). The second most often marked alternative was a foreman (in 22.6% of evaluation sheets), the third most often marked was the medical staff at the company (mentioned in 12.1% of evaluation sheets) and the fourth most often marked was workers themselves (mentioned in 7.5% of evaluation sheets). Only in 7.3% of the evaluation sheets was it indicated that someone other than the predefined alternatives should carry out the cold risks assessment at the workplace. Among these, a representative from the workers’ union and a head of unit were suggested.

4 DiscussionSimilarly to the results of field testing in the Nordic countries (Giedraityt et al., 2005), the observational checklist was found to be a usable tool for cold risk assessment, even when applied to companies with a different approach to safety culture. The results corresponded in terms of the instructions provided for the checklist and summary table; the facility of the checklist and summary table and the suitability of the checklist (in regards to the structure and content) for identifying cold-related risk factors. Furthermore, it complies well on these aspects with the recommendations given by Malchaire et al. (1999) for the ‘Observation’ method. The fact that no signs of learning effects in the evaluation sheets filled in after conducting the risk assessment procedure for the first, second and third time were found strengthens the idea that the checklist is rather straightforward and easy to use.

According to the Nordic observers (Giedraityt et al., 2005), a workers’ representative responsible for industrial safety and the workers themselves should carry out the assessment procedure at the workplace. On the contrary, the Russian observers mentioned workers only in 7.5% of the evaluation sheets, giving priority to a safety engineer (mentioned in 50.5% of evaluation sheets) and a foreman (mentioned in 22.6% of evaluation sheets). This contradicts the recommendation of Malchaire et al. (1999) that the persons performing the cold risk assessments should be the ones who are very well versed in the content of the work. In the case of Russian observers, it highlights a very interesting situation as the work safety engineer (category most often suggested by the observers) in one of the companies did not even know how many of the employees were working outdoors. The very low percentage of evaluation sheets where the alternative denoting the workers themselves was selected is likely an indication that the observers either have no interest or belief in their ability to influence or change their working environment.

According to Malchaire et al. (1999), the maximum time required to perform the risk assessment procedure on the ‘Observation’ level should be no longer than one hour. As each

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of the stages: preparation, realisation and analysis of results was most often described by the category of ‘less than 15 min’, the total time for performing the three categories is expected to be less than 45 minutes. There were differences in the categories chosen to describe the time needed to perform the last stage: discussion of results after conducting the cold risk assessment procedure for the first, second and third time. As the majority of the evaluation sheets filled in after the checklist was used for the first time indicated that no discussion took place on the possible preventive measures, the total time to carry out all four stages would be the same – under 45 minutes. After filling in the checklist for the second and third time, the absolute majority of the evaluation sheets suggested an expected total time for conducting all four stages of the assessment procedure to be a sum of four categories of ‘less than 15 min’, still in the line with the recommendations of Malchaire et al. (1999).

In conclusion, although the observers found the observational checklist to be a usable tool for cold risk assessment, interestingly, the workers at the observed workplaces would prefer that someone other than themselves should conduct cold risk assessment by means of the checklist.

Acknowledgments This study was partially supported financially by The Swedish Institute. We would like to thank all of the observers who participated in the study.

LiteratureBS 8800. Guide to occupational health and safety management systems. London: British

Standards Institution; 1996.

Cooper D. Improving safety culture: a practical guide. Chichester: John Wiley & Sons; 1998.

Council of the European Communities. Council Directive 89/391/EEC of 12 June 1989 on the introduction of measures to encourage improvements in the safety and health of workers at work. Official Journal 1989; L 183, 29/06/1989.

Dempsey PG, McGorry RW, Maynard WS. A survey of tools and methods used by certified professional ergonomists. Applied Ergonomics 2005; 36(4): 489–503.

Giedraityt L, Mäkinen TM, Holmér I, Hassi J. The field testing of an observational checklist for the assessment of cold-related risk factors. Int J Circumpolar Health 2005; manuscript accepted for publication.

Malchaire J, Gebhardt HJ, Piette A. Strategy for evaluation and prevention of risks due to work in thermal environments. Ann Occup Hyg 1999; 43(5): 367–76.

Munipov VM. Ergonomics and labour protection in the USSR and the commonwealth of independent states - historical landmarks and present status. Int J Industrial Ergonomics 1993; 11(2): 153–161.

Submitted to: Applied Ergonomics

PAPER III

Validation of the observational checklist for the assessment of

cold-related risk factors under laboratory conditions

Lina Giedraityt , Ingvar Holmér, Chuansi Gao and Kalev Kuklane

Lina Giedraityt ( )





Fax No: +46 920 491030


Ingvar Holmér, Chuansi Gao and Kalev Kuklane

Thermal Environment Laboratory

Department of Design Sciences

Lund Technical University

Box 118, 221 00 Lund, Sweden


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ABSTRACT

Various observational checklists for the assessment of risk factors in the workplace are being developed and used because of their efficiency advantages in terms of time and costs as well as their user friendliness. The objective of this study was to validate the checklist for the identification of cold-related problems under laboratory conditions in terms of whether the checklist generated results were in accordance with the subjects’ physiological measurements and self-reported observations of their thermal state. Eight male subjects were screwing bolts with both gloves and bare hands and stepping in 0°C, walking at 3.5 km/hour and 4.9 km/hour in –10°C and at 3 km/hour in –25°C and standing still at 4°C in the climatic chamber. In conclusion, the number of subjects who assessed the particular cold-related risk factor by means of the checklist in conformity to their reported thermal sensations and measured skin temperatures varied most often from five to eight subjects. In some rare cases, only one, two or three subjects gave evaluations that were in agreement. In particular, this was the case for risk factors concerning the presence of light work and protection of extremities against cold, when several work tasks were performed under the same experiment.

KEYWORDS

Cold work, observational checklist, laboratory validation

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1. IntroductionThere are many methods (checklists, assessment scales, observation techniques, sophisticated measurement procedures) available to assess various risks related to working environment. These are often developed by experts for experts. The four-stage approach developed by Malchaire and Cock (1999) enables the comparison of different types or ‘levels’ of risk assessment tools. This four-stage strategy successively increases its complexity from Screening through to Observation, Analysis and finally, Expertise. As the authors suggest, the philosophy behind the strategy is not specific to musculoskeletal disorders, the proposed application area in the article. The same approach can be used to evaluate and prevent risks due to work in thermal environments (Malchaire et al., 1999).

The tools intended for non-specialist users fall within the Screening and Observation stages of this proposed framework. These tools have to be simple and straightforward and assist employers and others in recognising, assessing and managing risk factors (Graves et al., 2004).

The observation of people performing various tasks at their workplaces provides a way of capturing data on physical task sequences, prevailing environmental conditions and interactions between workers as well as providing some insight into the ease or difficulty with which the task is performed. There are many and varied observational techniques, which fall into three broad categories: direct, indirect, and participant observation (Drury, 2005). In the latter approach, the observer actually performs the task or work under consideration.

Graves et al. (2004), based on the work of Li and Buckle (1999), cite the following advantages of observational techniques (used to prevent musculoskeletal disorders) that also apply to checklists: (a) simple to undertake and able to provide a quick answer; (b) relatively inexpensive; and (c) can be performed in the workplace without disruption to the workforce. However, the disadvantages of such techniques include: (a) the subjectivity of judgement relying on human observation (Chen et al., 1989) and (b) the lack of precision in observational techniques, i.e., they are subject to intra- and inter-observer variability (Burdorf et al., 1992).

There have been some attempts to validate developed observational tools for risks assessment. For example, Keyserling et al. (1993) validated a two-page checklist for determining the presence of ergonomic risk factors associated with the development of upper extremity cumulative trauma disorders intended for non-expert use. The checklist was used by plant personnel in 335 manufacturing and warehouse jobs. Results generated by the checklist were compared to the results of ergonomic analyses performed by persons with advanced training (Master degrees) in occupational ergonomics. Generally, results generated by the checklist were in agreement with those generated by the ergonomics analysts. Furthermore, the checklist was found to be more sensitive in identifying the presence of risk factors. Keyserling et al. (1993) concluded that the checklist was an effective rapid-screening instrument for identifying jobs that expose workers to potentially harmful ergonomic stresses.

The quick exposure checklist for assessing the exposure to risks for work-related musculoskeletal disorders developed by Li and Buckle (1999) has been used and validated by about 150 practitioners on both simulated and real tasks. The quick exposure checklist was found to have a high level of sensitivity and usability and largely acceptable inter- and intra-observer reliability (Li and Buckle, 2005).

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Despite the fact that checklists seem to have limitations on a scientific level, they continue to be developed and used because of their efficiency advantages in terms of time and costs as well their user friendliness (Graves et al., 2004).

The objective of this study was to validate the checklist for the identification of cold-related problems (Giedraityt et al., 2005) under laboratory conditions in terms of whether the checklist generated results were in agreement with the subjects’ physiological measurements and self-reported observations of their thermal state.

2. Methods and materials

2.1. Subjects

Eight healthy non-smoking male subjects volunteered to participate in the experiment. An information meeting was arranged for each of them individually, where they were informed of the procedures and potential risks of the experiment. All subjects signed an informed consent to participate in the experiment.

The subjects were asked not to drink alcohol 24 hours before the experiment, not to smoke, eat or drink tea/coffee for at least 2 hours before the experiment and not to exercise for at least one hour before the experiment.

The subjects were of 22–38 years of age (mean=28, SD=5), 53.0–87.6 kg of weight (mean=71.6, SD=11.1) and of 1.70–1.89 m of height (mean=1.81, SD=0.06). The subjects’ body surface area according to Du Bois ranged from 1.60 to 2.14 m2 (mean=1.91, SD=0.07). The subjects had the following occupations: a warehouseman (1), a medical doctor (1), a student (5), and a university lecturer (1). None of the subjects could be characterised as working in cold environments. However, all of them had a previous experience of cold exposures to temperatures at least as low as –20°C.

2.2. Experimental procedure

All clothes to be worn by the subjects during the particular activity (see table 1), skin temperature measurement sensors (NTC–resistant temperature matched thermistors ACC-001, Rhopoint Components Ltd, UK, accuracy ±0.2°C, time constant 10 seconds) and heart rate measuring device (Sport Tester, Polar Electro Oy, Finland) were weighed (Sartorius 3804MP weighing scale, Sartorius GMBH, Göttingen, Germany, accuracy ± 0.1 g) just before the subjects arrived. After the subjects undressed, inserted a rectal probe (YSI-401 Yellow Springs Instrument, USA, accuracy ±0.15°C) at a depth of 10 cm and put on boxer shorts, they were weighed (GWB Mettler ID2 MultiRange weighing scale, Albstadt, Germany, accuracy ±0.002 kg). The sensors were taped on the subjects’ skin with adhesive tape (3M Blenderm ™ surgical tape, type 1525) covering the thermistors. Before entering the climatic chamber the subjects were weighed with all clothing and measuring equipment. The subjects were weighed again right after they left the climatic chamber (at the end of the experiment). Each piece of clothing was weighed separately immediately after the subjects removed it. Right after the subjects were undressed and the measuring equipment was removed, the subjects were weighed wearing only the boxer shorts and the rectal sensor.

Tests were carried out during the winter season (January-February, 2005). Each subject performed each of the six activities during the same period of the day with intervals of at least one day in between the experiments. The activity levels of activities B, C, D E and F were calculated according to the IREQ-method (ISO/CD 11079, 2001) to levels ensuring thermal balance of the subjects for moderately heavy activity without sweating. According to the calculations based on the standard person, the subjects should feel thermally neutral or very

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slightly warm during these activities. On the contrary, during activity A, the activity levels were chosen such that the subjects were expected to experience cold stress during screwing while seated and overheating while performing a stepping test. The subjects were informed of the possibility to stop the experiments at any time should they feel that the experimental conditions were unbearable, in particularly during activity A.

The actual walking speeds for activities B, C, D and E were calculated as suggested by Givoni and Goldman (1971) and corrected for activities D and E for the increased energy costs (up to 1.0% of the estimated metabolic rate per 100 grams increase in weight of the footwear) due to the weight of footwear (Jones et al., 1984; Jones et al., 1986). The metabolic costs of activity E were also adjusted for the thickness of clothing. The energy costs of thicker clothing due to its stiffness and friction can be up to 16% higher (Teitlebaum and Goldman, 1972).

The subjects were performing activities A, B, C, D and E for 90 minutes and activity F for 60 minutes. During activities B, C, D and E the subjects walked on a treadmill (Exercise x-track elite, Exercise x.tech AS, Norway) and during activity F they were standing still. In the beginning of activity A, the subjects were sitting and screwing metal bolts into a vertical metal plate (20×45 cm) with 8×3=24 holes with bare hands (activity A1). The rate of screwing in was 1.73–3.62 screws/minute (mean=2.66, SD=0.51) and the rate of unscrewing was 2.17–3.73 screws/minute (mean=2.95, SD=0.39). After 20–30 minutes (depending on the subjective assessment of the subjects whether it was appropriate to continue until the estimated time of 30 minutes had elapsed), the stepping test (activity A2) was performed on a 25 cm high step at a rate of 100 steps/minute for 20–25 minutes, depending on the physical fitness of the subjects. At the end of activity A, the subjects were screwing the bolts again, but this time the bolts were wet and the subjects were wearing gloves (activity A3). The rate of screwing in was 1.48–2.63 screws/minute (mean=1.98, SD=0.31) and the rate of unscrewing was 1.68–3.51 screws/minute (mean=2.52, SD=0.52).

Exhaled air was collected with Douglas bags after 20, 50 and 80 minutes for activities B, C, D and E; after 20 and 50 minutes for activity F; after 10 min for activities A1 and A2; and after 30 min for activity A3. The exhaled air was collected for 3–4 minutes for walking and stepping and for 6–7 minutes for standing and screwing. The average value of these intervals was used as a representative value for the whole activity. The ambient air (for O2 and CO2 concentrations) in the climatic chamber was sampled and analysed using MetaMax equipment (Cortex GmbH, Germany) for periods when exhaled air was collected. After the experiment, the Douglas bags were emptied and the expired air was analysed for oxygen consumption ( 2OV ) with MetaMax equipment. The metabolic rate ( M ) for each activity was determined based on the measured 2OV (ISO 8996, 1990).

Skin and rectal temperatures as well as heart rate were measured continuously and recorded at intervals of 15 seconds. The ambient air temperature in the chamber was measured at 0.3 m, 1.4 m, 2.0 m from the floor (PT100, Class B sensor accuracy ±0.3°C at 0°C) continuously and recorded with a temperature data logger (PT-104; Pico technology Limited, accuracy ±0.01°C) at intervals of 15 seconds.

The rectal temperature was measured to represent the body core temperature ( coreT ). The mean skin temperature ( skinT ) was calculated according to the formula of Gagge and Nishi (1977) from the temperatures measured by the thermistors positioned on the subjects’ forehead, left scapula, left chest, left upper arm, left forearm, left dorsal hand, left anterior thigh and left calf. In order to measure finger skin temperatures thermistors were placed on the first phalanxes of the left little finger ( fingerlitleT _ ) and the right index finger ( fingerindexT _ ).

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Toe skin temperatures were derived from thermistors placed on the dorsal first phalanx of the left second toe ( toeT ) and facial temperature was obtained from a thermistor placed on the left cheek ( cheekT ). The latter four temperatures were used as a control (during the experiment) and reference temperatures for recorded subjective thermal sensations. Mean body temperature ( bodyT ) was calculated as a sum of mean skin temperature, skinT , (with coefficient 0.2) and body core temperature, coreT , (with coefficient 0.8) (ASHRAE, 1985). The body heat storage ( S ) was calculated as a function of the rate of change in mean body temperature bodyT (Gagge and Nishi, 1977).

The subjects’ perceived observations of the thermal sensation of the body, face, hands and feet were recorded using a scale from +4 (very hot) to –4 (very cold), which can be found in ISO 10551 (1995). Along with thermal sensations, the subjective judgments on thermal comfort/discomfort on a scale from 0 (comfortable) to 4 (very uncomfortable) and thermal preference on a scale from +3 (much warmer) to –3 (much cooler) were recorded as well (ISO 10551, 1995). Pain sensations in the feet, hands and face were recorded on a scale from 0 (no pain) to 4 (very very painful). These subjective judgments on the subjects’ thermal state and sensations were recorded immediately upon entering the climatic chamber and at each 10th

minute during the performed activity.

The subjects filled in the checklist for identifying cold-related problems at work (Giedraitytet al., 2005) after the experiment was finished and they had changed back into their own clothes. The subjects were instructed on how to use the checklist during the initial information session. Each subject filled in the checklist six times in total, i.e. a separate checklist after each experiment. As the checklist was used in its original form, some of the factors included in the checklist were not relevant to certain activities carried out during the experiment. The subjects were instructed to mark non-relevant factors as belonging to category ‘0 – no need for preventive actions’.

The subjects were asked by means of the checklist to assess the experimental conditions they were exposed to during the performed activity in terms of (1) whether cold air caused any problems, whether (2) air movements, (3) contact with cold surfaces, (4) exposure to water were present, whether the worn (5) protective clothing against cold as well as (6) protection of hands, feet and head against cold were sufficient and whether the (7) use of personal protective equipment interfered with work. Each of these seven factors had three alternatives illustrated with examples. The subjects had to choose one of three alternatives that best described each factor during the experiment. These alternatives were numbered from 0 to 2, where 0 stands for ‘no need for preventive actions’, 1 – ‘corrective actions are recommended in the long term’, 2 – ‘immediate need for corrective action’. Under the heading (8) ‘Other factors’ the subjects had to assess whether the following: long-term cold exposure, light work, highly varying workload, varying thermal environments, slipperiness and insufficient lighting were present during the experiment and to what extent. The latter was appraised on a scale from 0 – 2, using the same categories as explained above.

3. Results and discussion The calculated mean M , HR , S and a change in mean body temperature ( bodyT ) as well as the reported subjective thermal sensations in the whole body, feet, hands and face for all activities are shown in the table 2. bodyT for each activity is also depicted in figure 1. Mean

cheekT , fingerlitleT _ , fingerindexT _ and toeT for each activity are portrayed in figures 2 –7. The results

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from the subjects’ evaluations of the thermal conditions with the help of the checklist as well as the number of subjects who gave the same most common score for a particular cold-related risk factor during each performed activity are reported in table 3.

In order to determine the level of the performed physical activity, the measured metabolic rates were compared to those indicated in the ISO8996 (1990) standard: 100 W/m2

corresponds to a low activity level, 165 W/m2 – moderate and 290 W/m2 – very high.

In order to compare the results from physiological measurements and subjective thermal responses to the evaluations of the thermal conditions during the performed activities provided by the subjects from using the checklist the following criteria were established.

Local cooling of hands. If the actual measured fingerlitleT _ and fingerindexT _ were lower than the finger temperature threshold value for cold sensation of 15 oC, the subjects were expected to indicate in the checklist that protection of the extremities against cold was not sufficient (score 1 or 2 in the checklist). This threshold value was chosen based on the results reported by Geng et al. (2001). They found that cold and pain sensations were occurring when the finger skin and surface interface contact temperature was about 15 oC when touching nylon at a temperature of –20 oC, and 17 oC in the case of touching aluminum at –15 oC. However, they also reported considerable individual variations in cold sensations: some subjects felt extremely cold (rating –4 on the scale from 0 to –4) at the contact temperature of 7 oC, while others felt cold (rating –2 on the same scale) at the contact temperature of –3 oC. Similar findings were reported by Havenith et al. (1992): the slightly painful condition was associated with a skin temperature of 16 oC for the back and 19 oC for the palm of the hand. In a gripping experiment, the mean value, slightly painful (1) was observed when contact temperature dropped from 18 oC to 12 oC, depending on various types of material being gripped (Holmér et al., 2003). The mean thermal sensation of cold (score –2 on the scale from 0 to –4) occurred at the same range of temperatures. During convective cooling of the hand, Chen (1996) found similar finger temperatures to those reported by Geng et al. (2001) to be associated with cold and pain sensations. Furthermore, Enander (1984) reported a psychological adaptation among cold-accustomed individuals which resulted in reduced cold and pain sensations.

Local cooling of feet. If the actual measured toeT was lower than 20 oC, the subjects were expected to start feeling cold therefore, they should indicate in the checklist that the protection of the extremities against cold was not sufficient (score 1 or 2 in the checklist). This is based on the findings of Kuklane et al. (1998) who reported that thermal sensation correlated best with mean foot skin temperature, and the pain sensation had best correlation with toe skin temperatures. In the same study they found that slight pain could occur when mean foot skin temperatures were around 20–23 oC, and at temperatures below 20 oC pain sensation grew quickly. They also reported that the toe skin temperatures were usually about 6 oC lower than the mean foot skin temperatures, therefore toes started to feel cold at around 20 oC (a strong cold perception occurring at 10–15 oC) and painful at around 15 oC. Similar results were previously reported by Rintamäki and Hassi (1989).

Local cooling of face. If the actual measured cheekT was lower than 22 oC, the subjects were expected to start feeling cold on the face and indicate in the checklist that cold temperatures caused certain or obvious problems (score 1 or 2 in the checklist). The literature on relationships between the subjective thermal sensations and cheek skin temperatures is very scarce. This threshold value is based on the finding of Gavhed et al. (2000), who reported that subjects in their study felt pain when the skin temperature of the cheek was 10–22 oC.However, the reported thermal sensations in the face will be given priority in order to assess

7

whether the subjects filled in the checklist in accordance with their thermal sensations and measured cheekT .

Whole body cooling. If the calculated S corresponded to the cooling rate of about –40 Wh/m2, the subjects were expected to feel slightly cool and indicate in the checklist that protective clothing against cold was not sufficient (score 1 or 2 in the checklist). This threshold value is based the minimal IREQ which is regarded as the highest acceptable cooling of the body during prolonged exposures (ISO CD 11079, 2001).

3.1. Activity A

The average measured metabolic rate for activity A1 was M =69±13 W/m2, for activity A2 was M =346±37 W/m2 and for activity A3 was M =73±8 W/m2, which represents light and very high activity levels. However, only three out of eight subjects marked that light work was present during the performed activity. Only half of the subjects indicated that highly varying workload caused problems: two subjects marked it as causing certain problems (score 1) and two others marked it as causing obvious problems (score 2).

Although the wind in the climate chamber during activity A3 was only 0.34±0.13 m/s, the subjects were expected to mark that air movements were present during the performed activity, as they were seated right below the fan blowing cold air. Five subjects indicated that light air movements were felt during the performed activity.

As the subjects were screwing cold bolts during activities A1 and A3, they were expected to indicate in the checklist that they had contact with cold surfaces. Two subjects marked in the checklist that there was no contact with cold surfaces, while the other six indicated having contact with cold surfaces for either shorter (4 subjects) or longer (2 subjects) periods of time.

As the subjects were screwing wet bolts during activity A3, they were expected to mark in the checklist that they were exposed to water. All of the subjects indicated that exposure to water was present during activity A: six subjects indicated short periods of exposure and two subjects indicated long periods.

Six subjects indicated in the checklist that cold air did not cause any problems and two subjects marked that cold air caused certain problems. One of the two marking cold air as causing certain problems felt neutral in the face for most of the time (lowest recorded

cheekT =20.7 oC during the activity). The other subject felt slightly cool in the face while he was sitting and screwing (lowest recorded cheekT =19.3 oC during the activity). One subject among those marking cold air as causing no problems felt slightly cool in the face for the time he was sitting and screwing (lowest recorded cheekT =19.2 oC during the activity). The remaining five subjects in this group felt neutral for the most of the time (on 32 occasions out of 50 asked) and their cheekT ranged from 22.1 oC to 23.9 oC at the end of activity. It can therefore be concluded that 6 subjects assessed the whole body protection against cold in conformity to the measured cheekT and reported thermal sensations in the face, while one subject underestimated and another subject overestimated.

The subjects were expected to mark the protection of extremities against cold as insufficient as they worked with both bare hands and wet gloves during the performed activity; however, only two of the subjects indicated that the protection of extremities was insufficient. At the end of activity A1 when the measured finger skin temperatures were at their lowest subjects’

fingerlitleT _ varied from 9.7 oC to 14.7 oC and fingerindexT _ from 11.7 oC to 16.0 oC. The reported thermal sensations in the hands varied from slightly cool to very cold. At the end of activity

8

A3, seven subjects reported feeling slightly cool or cool in the feet (their toeT varied from 13.7oC to 25.1 oC) and one subject felt neutral ( toeT =27.3 oC). It can be deduced based on the above that six subjects overestimated the protection of extremities against cold.

Six subjects marked the whole body protection against cold as sufficient and two considered it fairly good. During activity A1, S and bodyT were negative for all of the subjects and five subjects felt slightly cool or cool at the end of this activity. Those three who felt neutral or slightly warm were loosing heat a little bit slower (their S varied from –15 to –17 W/m2,

bodyT =0.2 oC over the period of activity A1) than those five who felt slightly cool or cool (their S varied from –21 to – 33 W/m2, bodyT varied from –0.3 oC from to –0.4 oC). Only one of those feeling slightly cool or cool marked in the checklist that the whole body protection against cold was not sufficient, while others indicated that the protection was sufficient. The second subject indicating not sufficient protection felt slightly cool at the end of activity A3. The remaining two subjects who marked sufficient whole body protection felt neutral at the coldest during the whole time of activity A. It can be concluded that four subjects rated this cold-related risk factor in agreement with calculated physiological parameters and reported subjective thermal sensations in the whole body and four subjects overestimated the whole body protection against cold.

There were five non–relevant risk factors for this activity. Of these, one risk factor was rated as 0 by all of the subjects, two were rated as 0 by seven subjects and the remaining two were rated as 0 by six subjects. The ratings that were not 0 were given by three different subjects.

3.2. Activity B

According to the results of the checklist cold air did not cause any problems to 7 of the subjects and it caused certain problem to one subject. The latter felt slightly cool in the face for the most of the time spent in the climate chamber. His cheekT dropped from 26.6 oC at the beginning of the experiment to 16.5oC at the end. Two out of those seven marking cold air in the checklist as non-problematic, felt slightly cool or cool for the most of the time. Their

cheekT was 17.8 oC and 17.2 oC at the end of the activity. The average measured cheekT for the remaining five subjects who marked cold air as causing no problems was 20.2±3.1 oC, which is quite close to the selected threshold value and is difficult to interpret. However, their reported thermal sensations in the face ranged from slightly cool to slightly warm at the end of the experiment and cheekT varied from 15.5 oC to 24.1 oC. If the judgement is to be based on the reported subjective thermal sensations in the face and the measured cheekT , six of the subjects estimated this cold-related risk factor as expected and two subjects underestimated.

A majority of the subjects (six) evaluated the protection of the extremities against cold as being sufficient. This is supported by the actual measured skin temperatures on the fingers ( fingerlitleT _ =30.2±1.9 oC and fingerindexT _ =31.2±1.9 oC) and on the toe ( toeT =24.5±1.1oC) as well as by the subjective thermal sensations in the hands (the most common sensation was slightly warm) and in the feet (the most common sensation was neither warm nor cool) for the duration of the activity. However, two subjects indicated that the protection of the extremities was fairly good rather than sufficient. The cold sensation ratings in the feet given by one of them interchanged between –1 and –2 starting from the 30th minute until the end of the activity although his toeT =33.2 oC at the end of the activity was the highest temperature of all of the subjects. In judging whether he filled in the checklist in agreement with measured skin temperatures and reported thermal sensations, the priority to thermal sensations was given.

9

The second subject of those two indicating in the checklist that the protection of the extremities was not sufficient claimed that his feet were warm ( toeT =35.2 oC) and hands between slightly warm and warm ( fingerlitleT _ =31.9 oC, fingerindexT _ =30.9 oC) at the end of the experiment. It can be concluded that seven subjects rated the protection of extremities against cold in accordance with the measured skin temperatures and reported thermal sensations, while one subject underestimated.

The average measured M =161±8 W/m2 for the duration of the activity represented a moderate activity level and ensured the thermoneutral state of the subjects. The positive average S and bodyT over the period of 90 minutes suggests that the whole body protection against cold was sufficient, which was confirmed in the checklist by all of the subjects. Their subjective thermal sensations in the whole body varied from neutral to hot at the end of the activity.

There were ten non–relevant risk factors for this activity. Of these, four were rated as 0 by all of the subjects while the remaining six were rated as 0 by seven subjects. The ratings that were not 0 were given by four different subjects.

3.3. Activity C

Four of the subjects indicated that the cold air did not cause any problems and another four claimed that it caused certain problems. The most common subjective response score describing the cold sensation in the face during the whole period of the activity was 0 (36 times out of 80 recorded), while the median was –1 (slightly cold), as the cold sensations ranged from –1 to –2.5 (41 times out of 80). Two subjects of the four that indicated no problems gave a subjective cold sensation score of 0 ( cheekT =18.8 oC and 19.2 oC) while the other two gave –2 ( cheekT =18.3 oC and 18 oC) at the end of the activity. Those who claimed cold air causing certain problems estimated thermal sensation on the face as 0 (two subjects,

cheekT =18.6 oC and 17.5 oC) and as –1 (two subjects, cheekT =15.3 oC and 18.4 oC) at the end of activity. Based on the above, it can be concluded that four subjects evaluated this risk factor in conformity to their thermal sensations in the face and with measured cheekT , while two subjects overestimated and another two underestimated.

A majority of the subjects (five) claimed that the protection of the extremities against cold was not sufficient, rating it as 1 in the checklist, while the other three reported that the protection was sufficient. This was consistent with the subjective thermal sensations in the hands and measured finger skin temperatures of six subjects. Four subjects of the five indicating protection of extremities as not sufficient had fingerindexT _ =13.8–15.1 oC,

fingerlitleT _ =10.8–14.8 oC and reported subjective thermal sensations in the hands varying between cool and cold at the end of the activity. One subject in this group claimed that his hands felt cool (–2) and his thermal sensation judgment was most likely based on the sensations in the little finger and not on the index finger ( fingerlitleT _ =13.2 oC and

fingerindexT _ =22.1 oC, both at the end of the activity). Two of the three indicating that the extremity protection was sufficient had fingerindexT _ =22.6 oC and 29 oC, fingerlitleT _ = 13.5 oC and 28.2 oC and reported cold sensation scores –1 and 0 respectively. The remaining subject in this group had fingerindexT _ =12.1 oC (lowest of all of the subjects) and fingerlitleT _ =12.5 oC with an indicated hand thermal sensation as cool. The two subjects that had indicated sufficient extremity protection should have indicated protection of extremities as not sufficient if the

10

judgement was to be based on the measured finger skin temperatures and their subjective thermal responses, i.e. they overestimated the protection of extremities. The majority of the subjects (six) reported thermal sensation in the feet as neutral ( toeT =18.1–31.0) by the end of the activity. One subject felt cool ( toeT =11.8 oC) and another felt slightly cool ( toeT =15.6 oC)in the feet at the end of the activity. The first subject indicated in the checklist that the protection of the extremities against cold was not sufficient, while the latter was the subject who claimed a sufficient protection of extremities against cold.

The average measured M =152±11 W/m2 for the whole period of activity was slightly lower than the moderate activity level indicated in the standard (ISO8996, 1990). The negative average S and bodyT over the period of 90 minutes suggest that subjects were cooling down although very slowly as the rate of heat loss was about 9 W/m2 per hour. The most common thermal sensation score for the whole body was 0 (32 times out of 80). Five of the subjects felt neutral at the end of activity, one was slightly warm, one slightly cool and another felt cool. However, the S and bodyT values for the two subjects feeling slightly cool and cool did not differ from the rest of the subjects. The latter two indicated in the checklist that the protective clothing against cold was only partly sufficient, while others claimed that the whole body protection against cold was sufficient. It can be concluded that all of the subjects filled in the checklist in agreement with the reported thermal sensations.

There were ten non-relevant cold risk factors for this activity. Of these, three were rated as 0 by all of the subjects while the remaining seven were rated as 0 by five or seven subjects depending on the risk factor. The ratings that were not 0 were given by four different subjects.

3.4. Activity D

According to the results of the checklist cold air did not cause any problems to six of the subjects. In the case of four subjects, this is in accordance with their subjective thermal sensations in the face that varied from neutral to slightly warm and their average measured

cheekT =19.1±2.3 oC at the end of the activity. The other two subjects who indicated cold air as causing no problems reported feeling slightly cool ( cheekT =15.1 oC) and somewhere between cool and cold ( cheekT =18.1 oC) at the end of the activity. Two of the subjects indicated in the checklist that cold air caused certain problems. One of these subjects reported feeling neutral in his face for the whole period of the activity ( cheekT =31.6 oC at the end of the experiment). The other subject reported a score of –2.5 for his thermal sensation in the face ( cheekT =18.1 oC)at the end of the experiment. Therefore, five subjects marked this cold-related risk factor in the checklist in conformity to their reported thermal sensations in the face and measured

cheekT , while one subject overestimated and two subjects underestimated.

Half of the subjects indicated that the protection of extremities was sufficient while the other half reported that it was not sufficient. This evaluation must be based on the thermal sensations in the hands as the average measured toe skin temperatures were above the threshold value for most of the duration (the lowest average for all of the subjects

toeT =19.3±2.1 oC at the 14th minute, and rising from there until the end of the activity). The lowest average fingerlitleT _ temperatures were measured at the 11th minute ranging from 9.2 oCto 19.0 oC (average fingerlitleT _ =15.1±3.8 oC). Three subjects of the four claiming that protection of extremities against cold was not sufficient had the lowest finger skin temperatures; as low as 7.0 oC, 9.2 oC and 12.1 oC for fingerlitleT _ with thermal sensations in the

11

hands ranging from slightly cool to cold. The fourth subject had fingerlitleT _ =17.4 oC and

fingerindexT _ =29.0 oC as the lowest value with the thermal sensations as neither cold nor warm. Three subjects out of those four who indicated sufficient extremity protection had their lowest

fingerlitleT _ varying from 16.4 oC to 18.8 oC and fingerindexT _ ranging from 16.3 oC to 27.1 oC.Their thermal sensations in the hands were from neither cold nor warm to slightly warm for the most of the time. The fourth subject felt from slightly warm to warm for most of the duration, although his fingerlitleT _ dropped as low as 12.3 oC and fingerindexT _ as low as 14.4 oC. Therefore, six subjects estimated this cold-related risk in the checklist in agreement with their thermal sensations and measured skin temperatures, while one subject overestimated the extremities protection against cold and another underestimated.

The average measured M =194±19 W/m2 represented a moderate activity level, which resulted in negative S and bodyT over the period of 90 minutes. Although S and bodyT were negative, the rate of cooling of approximately 4 W/m2 per hour is negligible, and subjects should be in thermoneutral condition at the end of the activity. As expected, all eight subjects indicated in the checklist that the whole body protection against cold was sufficient, which is in accordance with the reported whole body thermal sensations that were neutral or warmer on 86 occasions out of 90 asked.

There were ten non-relevant cold risk factors for this activity. Of these, three were rated as 0 by all of the subjects, five were rated as 0 by seven subjects and the remaining two were rated as 0 by six subjects. The ratings that were not 0 were given by four different subjects.

3.5. Activity E

According to the checklist results the majority of the subjects (six) thought that cold air did not present any problem during the time they spent in the climate chamber, while the other two indicated that cold air caused certain (1 subject) and obvious (1 subject) problems. The two subjects who indicated that cold air was causing problems reported feeling slightly cool to cold in the face for most of the duration ( cheekT at the end of the activity was 21.4 oC and 16.6 oC respectively). Three subjects out of the six who marked cold air as non-problematic reported feeling slightly cool to cold on 29 occasions out of 30 asked. Their cheekT varied from 14.0 oC to 17. 9 oC at the end of activity. The remaining three subjects reported feeling from neutral to hot throughout the duration of the performed activity, although their cheekT was 15.25 oC, 16.4 oC and 19.1 oC at the end of the activity. It can be concluded, based on the above, that 5 subjects rated this cold-related risk factor in the checklist in conformity to the reported thermal sensations in the face while three subjects underestimated.

Half of the subjects marked the protection of extremities in the checklist as being sufficient while the other four marked it as fairly good. For the latter four, it must have been the protection of feet against cold that was not sufficient as all of the subjects reported the thermal sensations in the hands varying from neutral to very hot in 75 out of 80 recordings. This is verified by the measured average fingerindexT _ =31.3±2.3 oC and fingerlitleT _ =28.0±2.3 oC. The four reporting not sufficient protection of feet had the following toeT at the end of the activity: 12.3 oC (subjective thermal sensation was –2), 14.1 oC (subjective thermal sensation was –3), 11.5 oC (subjective thermal sensation was –2) and 34.7 oC (subjective thermal sensation was 2.5). The latter subject had toeT =24.1 oC in the beginning of the activity as the lowest temperature and reported neutral as the coldest thermal sensation over the duration of the experiment. Two of the subjects who evaluated the protection of extremities as sufficient felt

12

slightly cool at the end of the activity ( toeT =15.6 oC and 18.4 oC respectively). The first started feeling slightly cool when there was 30 minutes left until the end of the experiment, and the other with 50 minutes remaining. The remaining two subjects felt neutral at the end of the activity ( toeT =21.8 oC and 28.3 oC respectively). Therefore, five subjects evaluated this cold-related risk factor in the checklist in conformity to measured skin temperatures and reported thermal sensations, while one subject underestimated and the other two overestimated.

The activity performed by subjects ( M =162±19 W/m2) can be described as a moderate activity level if compared to the limits for various activities in the standard ISO8996 (1990). All of the subjects found the whole body protection against cold to be sufficient, which is supported by the positive average S and bodyT as well as by the reported subjective whole body thermal sensations. Their subjective responses varied from neutral (35 out of 80 recordings) to warm throughout the duration.

There were ten non–relevant cold risk factors for this activity. Of these four were rated as 0 by all of the subjects, five were rated as 0 by seven subjects and one was rated as 0 by five subjects. The ratings that were not 0 were given by six different subjects.

3.6. Activity F

According to the results of the checklist, five subjects thought that cold air was not a problem during the time they spent in the climate chamber while three subjects indicated that cold air caused certain problems. Two of the latter three felt neutral in the face throughout the duration of the activity ( cheekT =31.2 oC and 27.1 oC at the end of the activity). The third subject in this group felt either slightly cool or cool in the face most of the time. His cheekT is unknown, as the data for that particular sensor were lost during the experiment. The five subjects who evaluated cold air as not causing any problems reported feeling neutral at the coldest during the whole experiment. Their cheekT ranged from 27.1 oC to 30.5 oC at the end of the activity. Therefore, six subjects estimated this cold-related risk factor in agreement with the reported thermal sensations in the face and with measured cheekT while two subjects overestimated.

Five of the subjects indicated that the protection of extremities against cold was sufficient while three rated it as fairly good rather than sufficient. As all of the subjects reported thermal sensations in the hands varying from slightly warm to hot for the whole period of the activity (average fingerlitleT _ =33.6±1.4 oC and fingerindexT _ =34.1±1.4 oC for the whole period of time), the protection of feet is most likely to be the reason for marking the protection of extremities as insufficient. According to subjective thermal sensations in the feet, six of the subjects felt slightly cool or cool in their feet at the end of the activity. Three of them indicated in the checklist that the protection of extremities was not sufficient (at the end of the activity their

toeT was 18.7 oC, 19.7 oC and 32.7 oC respectively) while the other three rated it as sufficient (at the end of the activity their toeT was 15.6 oC, 17.8 oC and 18.4 oC respectively). The remaining two subjects marked the protection of extremities as sufficient; one felt hot in his feet ( toeT =30.2 oC) and one felt neutral ( toeT =31.6 oC) at the end of activity. It can be concluded that five subjects assessed the protection of extremities against cold in agreement to the reported thermal sensations and measured skin temperatures while three subjects underestimated it.

13

The average measured M =55±8 W/m2 indicates a very light activity level, which is even lower than the resting metabolic rate level provided in the standard ISO8996 (1990). Only one subject indicated that light work was present during the activity.

All of the subjects indicated that the whole body protection against cold was sufficient, which is supported by the positive average S and bodyT as well as by the reported subjective whole body thermal sensations. The subjects reported feeling from slightly warm to hot on 50 occasions out of 56 asked.

There were nine non–relevant cold risk factors for this activity. Of these, four were rated as 0 by all of the subjects, three were rated as 0 by seven subjects, one was rated as 0 by six subjects and one was rated as 0 by five subjects. The ratings that were not 0 were given by six different subjects.

In conclusion, the number of subjects who assessed the particular cold-related risk factor by means of the checklist in conformity to their reported thermal sensations and measured skin temperatures varied most often from five to eight for the factors that were relevant to the performed activity (see table 4). In some rare cases, only one, two or three subjects gave evaluations of the particular cold-related risk factor that agreed to their thermal sensations and measured skin temperatures. In particular, this was the case for risk factors concerning the presence of light work and protection of extremities against cold, when several work tasks were performed under the same experiment. In the case of non-relevant factors, most often seven or all eight subjects gave scores corresponding to the instructions given to subjects prior to the experiment.

Therefore it has to be kept in mind that in some cases up till around 35% of answers provided in the checklist might not necessarily reflect the real situation at the workplace. This is an important factor to take into consideration when planning cold risk prevention measures, as some observers might overestimate the protection against cold provided at the workplace.

Acknowledgements This work was partially funded from means allocated to the project "THERMPROTECT, Assessment of Thermal Properties of Protective Clothing and Their Use" under the European Union GROWTH programme. The project (contract: G6RD-CT-2002-00846) included research teams under the leadership of P. Broede (D), V. Candas, (F), E. den Hartog (NL), G. Havenith (UK), I. Holmér (S), H. Meinander (FIN) and M. Richards (CH).

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References ASHRAE, 1985. Physiological principles for comfort and health, in: ASHRAE, Handbook.

Fundamentals. ASHRAE, Atlanta, USA, chapter 8, p.p. 8.1–8.32.

Burdorf, A., Derksen, J., Naaktgeboren, B., van Riel, M., 1992. Measurement of trunk bending during work by direct observation and continuous measurement. Applied Ergonomics, 23(4), 263–267.

Chen, F., 1997. Thermal responses of the hand to convective and contact cold – with and without gloves. Arbetslivsinstitutet, Stockholm.

Chen, J.G., Peacock, J.B., Schlegel, R.E., 1989. An observational technique for physical work stress analysis. International Journal of Industrial Ergonomics, 3(3), 167–176.

Drury, C.G., 2005. Methods for direct observation of performance, in: Wilson J.R., Corlett N. (Eds.), Evaluation of human work: A practical ergonomics methodology, 3rd ed., Taylor & Francis, Boca Raton, Florida, p.p. 45–68.

Enander, A, 1984. Performance and sensory aspects of work in cold environments: a review. Ergonomics 27(4), 365–378.

Gagge, A.P., Nishi, Y., 1977. Heat exchange between human skin surface and thermal environment, in: Lee, D.H.K (Ed.), Handbook of physiology: a critical, comprehensive presentation of physiological knowledge and concepts. Sect. 9. Reactions to environmental agents. American physiological society, Washington, D.C., chapter 5, p.p. 69–92.

Gavhed, D., Mäkinen, T., Holmér, I., Rintamäki, H., 2000. Face temperature and cardiorespiratory responses to wind in thermoneutral and cool subjects exposed to

10°C. European Journal of Applied Physiology, 83 (4 5), 449 456.

Geng, Q., Homér, I., Coldsurf Research group, 2001. Change in contact temperature of finger touching on cold surfaces. International Journal of Industrial Ergonomics, 27(6), 387–391.

Giedraityt , L., Mäkinen, T., Holmér, I., Hassi, J., 2005. The field testing of an observational checklist for the assessment of cold-related risk factors. International Journal of Circumpolar Health, manuscript accepted for publication.

Givoni, B., Goldman R.F., 1971. Predicting metabolic energy cost. Journal of Applied Physiology, 30(3), 429–433.

Graves, R.J., Way, K., Riley, D., Lawton, C., Morris, L., 2004. Development of risk filter and risk assessment worksheets for HSE guidance – 'Upper Limb Disorders in the Workplace' 2002. Applied Ergonomics, 35(5), 475–484.

Havenith, G., Van de Linde, E.J.G., Heus, R., 1992. Pain, thermal sensation and cooling rates of hands while touching cold materials. European Journal of Applied Physiology and Occupational Physiology, 65(1), 43–51.

Holmér, I., Geng, Q, Havenith G., Hartog E., Rintamäki, H., Malchaire, J., Piette A., 2003. Temperature limit values for cold touchable surfaces. Final report on the project: SMT4-CT97-2149. Arbetslivsinstitutet, Stockholm.

ISO 8996, 1990. Ergonomics of the thermal environment – Determination of metabolic rate.

International Organization for Standardization, Geneva.

15

ISO 10551, 1995. Ergonomics of the thermal environment – Assessment of the influence of the thermal environment using subjective judgement scales. International Organization for Standardization, Geneva.

ISO CD 11079, 2001. Ergonomics of the thermal environment – Determination and interpretation of cold stress when using required clothing insulation (IREQ) and local cooling effects. International Organization for Standardization, Geneva.

ISO FDIS 15831, 2003. Clothing – Physiological effects – Measurement of thermal insulation by means of a thermal manikin. International Organization for Standardization, Geneva.

Jones, B.H., Toner M.M., Daniels, W.L., Knapik, J.J., 1984. The energy cost and heart-rate response of trained and untrained subjects walking and running in shoes and boots. Ergonomics, 27(8), 895–902.

Jones, B.H., Knapik, J.J., Daniels, W.L., Toner, M.M., 1986. The energy cost of women walking and running in shoes and boots. Ergonomics, 29(3), 439–443.

Keyserling, W.M., Stetson, D.S., Silverstein, B.A., Brouwer, M.L., 1993. A checklist for evaluating ergonomic risk factors associated with upper extremity cumulative trauma disorders. Ergonomics, 36(7), 807–831.

Kuklane, K., Geng, Q., Holmér, I., 1998. Effect of footwear insulation on thermal responses in the cold. International Journal of Occupational Safety and Ergonomics, 4(2), 137–152.

Kuklane, K., Sandsund, M., Reinertsen, R.E., Tochihara Y., Fukazawa, T., Holmér, I, 2004. Comparison of thermal manikins of different body shapes and size. European Journal of Applied Physiology, 92(6), 683–688.

Li G., Buckle, P., 1999. Evaluating change in exposure to risk for musculoskeletal disorders –A practical tool, Contract Research Report 251/1999. HSE Books, Sudbury, Suffolk.

Li G., Buckle, P., 2005. Quick exposure checklist (QEC) for the assessment of workplace risks for work related musculoskeletal disorders (WMSDs), in: Stanton, N., Hedge, A., Brookhuis, K., Salas, E., Hendrick, H. (Eds.), Handbook of human factors and ergonomics methods. CRC Press, New York, chapter 6, p.p. 6.1–6.10.

Malchaire, J., Cock, N.A., 1999. Risk prevention and control strategy for upper limb musculoskeletal disorders. TUTB Newsletter, 11, 27–31.

Malchaire, J., Gebhardt, H.J., Piette, A, 1999. Strategy for evaluation and prevention of risks due to work in thermal environments. Annals of Occupational Hygiene, 43 (5), 367–376.

Meinander, H., Anttonen, H., Bartels, V., Holmer, I., Reinertsen, R.E., Soltynski, K., Varieras, S., 2003. Thermal insulation measurement of cold protective clothing using thermal manikins, in: Report series: Fibre Materials Science. Tampere University of Technology, Tampere, Report 4.

Rintamäki, H., Hassi., J., 1989. Foot temperature and thermal sensations in the foot in the naked and clothed man, in: Mercer, J.B. (Ed), Thermal physiology 1989: proceedings of the International Symposium on Thermal Physiology, Tromsø, Norway, 16-21 July 1989. Elsevier, Amsterdam, p.p. 173–176.

Teitlebaum, A., Goldman, R.F., 1972. Increased energy cost with multiple clothing layers. Journal of Applied Physiology, 32(6), 743–744.

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35,9

36,1

36,3

36,5

36,7

36,9

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

Time from the start of the experiment, (min)

Body

tem

pera

ture

, (°C

)

Activity A1 Activity A2 Activity A3 Activity BActivity C Activity D Activity E Activity F

Figure 1. bodyT of the subjects (n=8) during various activities1.

1The lines in the graph representing activities A1, A2 and A3 are showing bodyT as if all the subjects started stepping at the 31st minute and stopped at the 51st minute, although the subjects started stepping between the 30th and 35th minute and screwing between the 50th and 58th minute. bodyT of activity A1 during last 7 minutes is based on the data from 7 subjects, as one subject chose to stop screwing at the 24th minute.

17

10

13

16

19

22

25

28

31

34

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90


Skin

tem

pera

ture

, (°C

)

Cheek (A1) Cheek (A2) Cheek (A3)Left little finger (A1) Left little finger (A2) Left little finger (A3)Right index finger (A1) Right index finger (A2) Right index finger (A3)2nd left toe (A1) 2nd left toe (A2) 2nd left toe (A3)

Figure 2: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were screwing with bare hands (activity A1), stepping (activity A2) and screwing with wet gloves (activity A3)2.2The lines in the graph representing mean skin temperatures are shown as if all the subjects started stepping at the 31st minute and stopped at the 51st minute, although the subjects started stepping between the 30th and 35th minute and screwing between the 50th and 58th minute. bodyT of activity A1 during last 7 minutes is based on the data from 7 subjects, as one subject chose to stop screwing at the 24th minute.

17

20

23

26

29

32

35

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90


Skin

tem

pera

ture

, (°C

)

Cheek Left little finger Right index finger 2nd left toe

Figure 3: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were walking at 3.5 km/h (activity B).

18

13

16

19

22

25

28

310 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90


Skin

tem

pera

ture

, (°C

)


Figure 4: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were walking at 3.5 km/h (activity C).

14

17

20

23

26

29

32

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90


Skin

tem

pera

ture

, (°C

)


Figure 5: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were walking at 4.9 km/h (activity D).

19

15

18

21

24

27

30

330 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85


Skin

tem

pera

ture

, (°C

)


Figure 6: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were walking at 3.0 km/h (activity E).

22

25

28

31

34

0 5 10 15 20 25 30 35 40 45 50 55 60


Skin

tem

pera

ture

, (°C

)


Figure 7: Mean cheekT , fingerlitleT _ , fingerindexT _ and toeT whilst subjects (n=8) were standing still (activity F).

20

Tabl

e 1.

Des

crip

tion

of a

ctiv

ities

in te

rms o

f clo

thin

g1 use

d, n

atur

e of

the

activ

ity a

nd e

nviro

nmen

tal c

ondi

tions

.

Act

ivity

cod

e an

d na

me

Tem

pera

ture

and

win

d D

escr

iptio

n an

d du

ratio

n of

the

activ

ity

Clo

thin

g

A: s

crew

ing

and

step

ping

A1:

scre

win

g

A2:

step

ping

A3:

scre

win

g

0°C

, < 0

.2 m

/s

0°C

, < 0

.2 m

/s

0°C

, 0.

34 ±

0.13

m/s

Scre

win

g w

ith b

are

hand

s (2

5–30

min

)

Step

ping

(20–

25 m

in)

Scre

win

g w

ith w

et g

love

s (~

40 m

in)

Box

er sh

orts

(Tai

ga n

o. 2

0122

, Haw

k), p

olo

shirt

(Hel

lyH

anse

n no

. 750

07),

pant

s (H

elly

Han

sen

no.

7540

1), j

acke

t (Le

ijona

no.

336

320-

076-

74),

trous

ers (

Leijo

na n

o. 3

3900

1-00

76-7

4), s

ocks

(Ullf

rotté

no

. 976

, 400

g/m

2 ), sp

ort s

hoes

(Arb

esko

no.

3099

), gl

oves

(Hes

tra n

o. 3

128)

and

cap

(Tai

ga n

o.

2592

8 R

ohn)

. cl

eI

of t

he fu

ll en

sem

ble

was

0.2

63 m

2 °C/W

and

with

out g

love

s – 0

.258

m2 °C

/W.

B: w

alki

ng

-10°

C,

< 0.

2 m

/s

Wal

king

on

a tre

adm

ill a

t 3.

5 km

/hou

r (90

min

) B

oxer

shor

ts (T

aiga

no.

201

22, H

awk)

, pol

o sh

irt (H

elly

Han

sen

no. 7

5007

), pa

nts (

Hel

lyH

anse

n no

. 75

401)

, jac

ket (

Hel

lyH

anse

n no

. 062

66),

trous

ers (

Hel

lyH

anse

n no

. 065

01),

jack

et (L

eijo

na n

o.

3363

20-0

76-7

4), t

rous

ers (

Leijo

na n

o. 3

3900

1-00

76-7

4), s

ocks

(Ullf

rotté

no.

976

, 400

g/m

2 ), sa

fety

bo

ots (

Tem

pex

no.7

30 8

880)

, low

tem

pera

ture

mitt

ens (

Tem

pex

no. 4

13 1

290)

and

cap

(Tai

ga n

o.

2592

8 R

ohn)

. cl

eI

= 0.

375

m2 °C

/W.

C: w

alki

ng

-10°

C,

< 0.

2 m

/s

Wal

king

on

a tre

adm

ill a

t 3.

5 km

/hou

r (90

min

)

D: w

alki

ng

-10°

C,

< 0.

2 m

/s

Wal

king

on

a tre

adm

ill a

t 4.

9 km

/hou

r (90

min

)

2 Box

er sh

orts

(Tai

ga n

o. 2

0122

, Haw

k), p

olo

shirt

(Hel

lyH

anse

n no

. 750

07),

jack

et (H

elly

Han

sen

no.

0626

6), j

acke

t (Le

ijona

no.

336

320-

076-

74),

trous

ers (

Leijo

na n

o. 3

3900

1-00

76-7

4), s

ocks

(Ullf

rotté

no

. 976

, 400

g/m

2 ), sp

ort s

hoes

(Arb

esko

no.

3099

), gl

oves

(Hes

tra n

o. 3

128)

and

cap

(Tai

ga n

o.

2592

8 R

ohn)

. cl

eI

= 0.

281

m2 °C

/W.

E: w

alki

ng

-25°

C

< 0.

2 m

/s

Wal

king

on

a tre

adm

ill a

t 3

km/h

our (

90 m

in)

F: st

andi

ng

+4 °C

<

0.2

m/s

St

andi

ng (6

0 m

in)

Box

er sh

orts

(Tai

ga n

o. 2

0122

, Haw

k), j

acke

t (U

llfro

tté n

o. 9

62, 4

00 g

/m2 ),

pant

s (U

llfro

tté n

o. 9

65,

400

g/m

2 ), ja

cket

(Hel

lyH

anse

n no

. 062

66),

trous

ers (

Hel

lyH

anse

n no

. 065

01),

jack

et (T

empe

x no

. 39

0 22

01),

trous

ers (

Tem

pex

no. 3

92 0

201)

, soc

ks (U

llfro

tté n

o. 9

76, 4

00 g

/m2 ),

sock

s (H

elly

Han

sen

no. 0

6464

), sa

fety

boo

ts (T

empe

x no

.730

888

0), l

ow te

mpe

ratu

re m

itten

s (Te

mpe

x no

. 413

129

0) a

nd

Ala

skan

hoo

d (T

empe

x no

. 310

103

0).

cle

I=

0.46

9 m

2 °C/W

:

1 The

effe

ctiv

e cl

othi

ng in

sula

tion

(cl

eI

) was

mea

sure

d on

the

ther

mal

man

ikin

(Kuk

lane

et a

l., 2

004;

Mei

nand

er e

t al.,

200

3).

2 The

sam

e cl

othi

ng e

nsem

ble

was

use

d du

ring

activ

ities

C a

nd D

. Diff

eren

t cl

eI

val

ues

wer

e ac

quire

d ac

cord

ing

to d

iffer

ent c

alcu

latio

n m

etho

ds fo

r det

erm

inin

g th

erm

al

insu

latio

n by

mea

ns o

f the

rmal

man

ikin

: ser

ial (

0.39

8 m

2 °C/W

) for

act

ivity

C a

nd p

aral

lel (

0.28

1 m

2 °C/W

) for

act

ivity

D (I

SO F

DIS

158

31, 2

003)

. In

orde

r to

com

pare

th

ese

met

hods

wal

king

spee

ds w

ere

chos

en to

cor

resp

ond

with

ther

mal

neu

tralit

y ac

cord

ing

to IR

EQ (I

SO/C

D 1

1079

, 200

1)

21

Tabl

e 2.

Sub

ject

s’ m

easu

red

phys

iolo

gica

l cha

ract

eris

tics a

nd p

erce

ptua

l jud

gmen

ts o

n th

eir p

erso

nal t

herm

al st

ate

for t

he d

urat

ion

of

activ

ities

A1,

A2,

A3

and

for 3

0 m

inut

e in

terv

als o

f act

iviti

es B

to F

as w

ell a

s for

the

who

le p

erio

d of

act

iviti

es B

to F

. T

herm

al se

nsat

ions

M

, W/m

2 H

R,

b/

iS,

W/m

2T

body

, °C

Who

le b

ody

Feet

Han

dsFa

cem

ean

SD

mea

n SD

mea

nSD

mea

nSD

Mod

e M

edia

nM

ode

Med

ian

Mod

eM

edia

nM

ode

Med

ian

Act

ivity

A

A1

6913

84

22

–23

7–0

.31

0.10

00

–1–0

.5–2

–20

0A

2 34

637

12

7 18

7125

0.68

0.66

32.

752

03

10

1A

3 73

8 87

12

–35

14–0

.59

0.16

00

00

0–0

.50

0A

ctiv

ity B

1st

–30th

min

161

9 91

9

67

0.08

0.09

00

00

00

00

31st–6

0th m

in15

97

91

207

70.

100.

092

1 2

0.5

11

00

61st–9

0th m

in16

210

91

9

–15

–0.0

20.

071

1 2

11

10

01st

–90th

min

161

8 91

9

43

0.16

0.11

01

00.

251

10

0A

ctiv

ity C

1st

–30th

min

153

11

91

9–2

78

–0.3

50.

100

0 0

00

–1–1

–131

st–6

0th m

in15

412

88

19

–76

–0.1

00.

080

0 0

0–1

–10

–161

st–9

0th m

in15

113

86

7

–63

–0.0

90.

040

0 0

0–2

–20

–0.5

1st–9

0th m

in15

211

88

8

–13

4–0

.54

0.16

00

00

–2–1

.25

0–1

Act

ivity

D

1st–3

0thm

in19

520

94

8

–16

12–0

.22

0.17

00

00

0–0

.75

0–0

.531

st–6

0th m

in19

323

93

10

18

0.01

0.11

11

11

00

00

61st–9

0th m

in19

317

95

11

–26

–0.0

30.

090

1 2

1.5

11

00

1st–9

0th m

in19

419

94

9

–64

–0.2

40.

160

1 1

10

00

0A

ctiv

ity E

1st

–30th

min

169

16

97

915

210.

200.

280

0.5

00

00.

25–1

–131

st–6

0th m

in16

424

96

9

45

0.05

0.06

00.

75–1

–11

10

–161

st–9

0th m

in15

317

97

11

–15

–0.0

10.

060

1 –1

–10

10

–11st

–90th

min

162

19

96

96

70.

230.

290

1 –1

–10

1–1

–1A

ctiv

ity F

1st–3

0thm

in56

11

89

1613

100.

170.

132

2 –1

02

20

031

st–6

0th m

in54

6 89

15

–56

–0.0

70.

082

2 –1

–11

1.25

00

1st–6

0th m

in55

8 89

15

46

0.09

0.17

22

–1–1

12

00

22

Tabl

e 3.

The

resu

lts o

f the

ass

essm

ent o

f col

d-re

late

d ris

k fa

ctor

s car

ried

out b

y th

e su

bjec

ts u

sing

the

chec

klis

t.

Mod

e (m

in –

max

) for

a c

erta

in a

ctiv

ity

The

num

ber o

f sub

ject

s who

gav

e th

e sa

me

mos

t com

mon

ratin

g fo

r a c

erta

in a

ctiv

ity

Ris

k fa

ctor

A

B

C

D

E F

AB

CD

EF

Col

d ai

r0

(0–1

)0

(0–1

)0

(0–1

)0

(0–1

)0

(0–2

)0

(0–1

)6

74

66

5

Win

d/ a

ir m

ovem

ents

1 (0

–1)

0 (0

–1)

0 (0

–1)

0 (0

–1)

0 (0

–1)

0 (0

–1)

57

76

77

Touc

hing

col

d su

rfac

es

1 (0

–2)

0 (0

–0)

0 (0

–0)

0 (0

–0)

0 (0

–0)

0 (0

–0)

48

88

88

Wat

er/ l

iqui

ds/ d

amp

1 (1

–2)

0 (0

–1)

0 (0

–1)

0 (0

–1)

0 (0

–1)

0 (0

–1)

67

77

77

Prot

ectiv

e cl

othi

ng a

gain

st c

old

0 (0

–1)

0 (0

–0)

0 (0

–1)

0 (0

–0)

0 (0

–0)

0 (0

–0)

68

68

88

Prot

ectio

n of

ext

rem

ities

aga

inst

col

d 0

(0–2

)0

(0–1

)1

(0–1

)1

(0–1

)1

(0–1

)0

(0–1

)5

65

44

5

Use

of P

PE

0 (0

–1)

0 (0

–0)

0 (0

–0)

0 (0

–0)

0 (0

–1)

0 (0

–0)

68

88

78

Oth

er p

robl

ems:

Long

-term

col

d ex

posu

re

0 (0

–1)

0 (0

–1)

0 (0

–2)

0 (0

–1)

0 (0

–2)

0 (0

–0)

67

57

58

Ligh

t wor

k 0

(0–1

)0

(0–1

)0

(0–2

)0

(0–1

)0

(0–1

)0

(0–1

)5

75

67

7

Hig

hly

vary

ing

wor

kloa

d 0

(0–2

)0

(0–1

)0

(0–2

)0

(0–1

)0

(0–1

)0

(0–2

)4

77

77

5

Var

ying

ther

mal

env

ironm

ents

0

(0–0

)0

(0–1

)0

(0–2

)0

(0–1

)0

(0–0

)0

(0–1

)8

75

78

6

Slip

perin

ess

0 (0

–1)

0 (0

–0)

0 (0

–1)

0 (0

–1)

0 (0

–0)

0 (0

–1)

78

77

87

Insu

ffic

ient

ligh

ting

0 (0

–1)

0 (0

–0)

0 (0

–1)

0 (0

–1)

0 (0

–0)

0 (0

–1)

78

88

88

23

Table 4. The number of subjects who assessed the particular cold-related risk factor in accordance with the reported thermal sensations and measured skin temperatures or in agreement with given instructions, in the case of non–relevance.

ActivityRisk factor A B C D E F

Cold air 6 6 4 5 5 6

Wind/ air movements 5 7 7 6 7 7

Touching cold surfaces 6 8 8 8 8 8

Water/ liquids/ damp 8 7 7 7 7 7

Protective clothing against cold 4 8 8 8 8 8

Protection of extremities against cold 2 7 6 6 5 5

Use of PPE 6 8 8 8 7 8

Other problems:

Long–term cold exposure 6 8 5 7 5 8

Light work 3 7 5 6 7 1

Highly varying workload 4 7 7 7 7 5

Varying thermal environments 8 7 5 7 8 6

Slipperiness 7 7 7 7 8 7

Insufficient lighting 7 8 8 8 8 8

Submitted to: International Journal of Industrial Ergonomics

PAPER IV

Observed cold-related risk factors for indoor and outdoor work in

the Nordic countries and north-western Russia

Lina Giedraityt , Tiina M. Mäkinen, John Abeysekera, Ingvar Holmér and Juhani Hassi

Lina Giedraityt ( )





Fax No: +46 920 491030


Tiina M. Mäkinen and Juhani Hassi

Centre for Arctic Medicine

Thule Institute

University of Oulu

90014 Finland

John Abeysekera

Dept. of Human Work Sciences



Ingvar Holmér

Thermal Environment Laboratory

Department of Design Sciences

Lund Technical University

Box 118

221 00 Lund, Sweden


1

ABSTRACT

The aim of this study was to identify cold-related risk factors that people face in their work environment and to investigate whether the region where the checklist was filled in, the type of work (indoor versus outdoor work), ambient temperatures and the sector that the company represented had any influence on the ratings that these factors received. Cold-related risk factors were assessed in 14 companies representing various work activities in construction, stevedoring and storage, tourism, sawmills, fish processing, forestry and road building industries in four countries: Finland, Norway, Sweden and north-western Russia. An observational checklist for the assessment of 13 cold-related risk factors was applied and 164 checklists were filled in by 80 selected observers in the Nordic countries and 277 checklists were completed by 116 selected observers in north-western Russia. The observers consisted of worksite managers, occupational health and safety (OH&S) representatives, occupational nurses and the workers themselves. The majority of the cold-related risk factors were rated differently by Nordic and Russian observers in term of either the chosen severity of the problem (‘no problem’, ‘slight problem’ or ‘considerable problem’) or the frequencies of ratings along these categories. Five factors (‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’ and ‘highly varying workload’) were most often rated as slightly problematic and two factors (‘protective clothing against cold’ and ‘light work’) as causing no problems by both groups. The remaining six factors (‘protection of extremities against cold’, ‘use of PPE’, ‘long-term cold exposure’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’) were rated differently by Nordic and Russian observers, and the latter indicated less favourable situations at the observed workplaces. Only a few factors had different ratings if various variables (nature of work, ambient temperatures and sector of economic activities) were taken into account.

RELEVANCE TO INSDUSTRY

Many people engaged in different occupations face cold exposure of varying duration and intensity every day at their workplaces.

KEYWORDS

Cold work, Risk factors, Cold indoor work, Cold outdoor work, Checklist

2

1 Introduction Cold is a hazard at the workplace in many different ways. Cold in combination with other environmental factors such as slipperiness or lack of light increases the risk of accidents. It also alters the functioning of tools and machinery. Cold affects the whole-body as well as the local heat balance of the extremities, skin and lungs. Cooling of the whole body or parts of the body results in discomfort, impaired sensory and neuromuscular function and, ultimately, cold injury (Holmér et al., 1998). Furthermore, prevention of cooling by means of cold protective clothing and other protective equipment interferes with the mobility and dexterity of the worker, restricting movements and motions and thus rendering them more exhausting (Holmér et al., 1998). The impaired performance capability may reduce the amount and quality of the work carried out (Enander, 1984). A recent study concerning construction work in Finland showed that building during the winter causes additional personnel costs. These were attributed to the longer working times needed under cold conditions and the decrease in work efficiency, assessed in terms of the earnings of individual employees (Juopperi et al., 2000).

Many persons engaged in different occupations face cold exposure of varying duration and intensity. In Sweden, for example, 16.4 % of all employed people (about 4.2 million) in 2001 were exposed to cold work outdoors during winter months or a cold indoor climate for at least a quarter of their working time. If the statistics are divided by gender, 22.7% of all employed men and 9.5% of all employed women were exposed to cold environment at their workplaces for at least a quarter of their working time (Statistics Sweden, 2002). The percentages are somewhat higher than those of 1999, when 14.8 % of all employed persons (or 21.5% of men and 7.3 % of women) faced such working conditions (Statistics Sweden, 2000).

In Sweden, the occupational groups (according to the Swedish Standard Classification of Occupations, SSYK) most exposed to cold, are: skilled agricultural and fishery workers (60.6% of employed persons in this group are exposed to cold at least a quarter of the time); craft and related trades workers (38.4%), especially subgroups such as building frame and related trades workers (67.0%) and building finishers and related trades workers (45.5%) falling under this category; and plant and machine operators and assemblers (29.1%), especially the subgroups of motor-vehicle drivers (53.4%) and agricultural and other mobile-plant operators (49.8%). In the remaining occupational groups the percentages of exposed workers vary from 2.0 to 25.2%, with certain subgroups having very high percentages such as child-care workers (40.6%), teaching associate professionals (30.5%) and stock clerks and storekeepers (29.0%) (Statistics Sweden, 2002).

In Finland, the weekly duration of exposure to cold at work was reported to be the largest (slightly over 20 hours) among construction workers, assemblers and repairers; higher than average (13 hours) exposure time was reported in farming, military and processing occupations (Hassi et al., 1998).

In the Nordic countries several questionnaire surveys have been carried out in which experience concerning the physical hazards of workplaces have been investigated. In these studies, it was found that 17–28 % of the employees experience draughts and 14–16 % experience coldness as a hazard in their work (Pekkarinen, 1994).

In 2001 in Sweden 0.7% of all employed men and 0.5% of all employed women had work related disorders during the previous twelve months (the time of the survey being a starting point) due to heat, cold or draught (Statistics Sweden, 2005). The percentage was somewhat higher (1.2–2.0%) for the subgroups with the highest share of exposed persons.

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Ramsey et al. (1983) found that ambient temperature had a statistically significant effect on the so called unsafe behaviour index (UBI). According to the authors, this relationship forms a U-shaped curve, with minimum UBI values occurring in the preferred temperature zone of 17 to 23ºC wet bulb globe temperature (WBGT). If the ambient temperature increases above or decreases below the preferred range, the proportion of unsafe behaviour increases. Cold is thus an important risk factor that has to be assessed for the maintenance of health, performance and efficiency at the workplace.

The aim of this study was to identify cold-related risk factors that people face in their work environment and to investigate whether the region where the checklist was filled in, type of work (indoor versus outdoor work), ambient temperatures and the sector that the company represented had any influence on the ratings that these factors received.


2.1 SubjectsCold-related risk factors were assessed at 14 companies in four countries: Finland, Norway, Sweden (during December 2000 – April 2001) and north-western Russia (during December 2003 – March 2004). An observational checklist for the assessment of cold-related risk factors (Giedraityt et al., 2005) was used by 196 selected observers to rate 13 risks factors: ‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’, ‘protective clothing against cold’, ‘protection of extremities against cold’, ‘use of personal protective equipment (PPE)’, ‘long-term cold exposure’, ‘light work’, ‘highly varying workload’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’. A total of 164 checklists were filled in the Nordic countries and 277 checklists were filled in north-western Russia (Archangelsk region).

In Finland, four foremen, three occupational nurses and seven workers observed cold-related risk factors at two construction companies (29 checklists filled in), two stevedoring and cargo handling companies (28 checklists), the skiing and arctic golf centre (6 checklists) and a small company providing electrical installation services (9 checklists). There were 72 checklists in total returned by Finnish observers. In the cases of the foremen and occupational nurses (except for the two nurses at the electrical installations company), the same person evaluated several working activities at the workplace on a single occasion using separate checklists for each observed activity. Therefore, the total number of the returned Finnish checklists is higher than the total number of the persons multiplied by the checklist testing occasions. The stevedoring and cargo handling involved work (some of it relatively light) conducted in cold and often windy conditions which may cause rapid body cooling. One characteristic problem area for this industry was that repair and maintenance work had to be conducted outdoors regardless of the ambient temperatures.

In Norway, the cold-related risk factors were observed 48 times at two fish processing companies by an occupational health and safety representative (1) and workers (47). The Norwegian observers were evaluating cold-related risk factors during the preparation of fish filets in indoor facilities. Climatic conditions were rather uneven with environmental temperatures of 23–24°C at the filet cutters’ head level, 10°C at foot level (for static work), and 6°C on the concrete floor. The workers had a limited thermal protection on their hands as the detection of bones in the fish meat relied mostly on finger sensitivity. Furthermore, due to food quality reasons, the fish meat must be kept at temperatures lower than 8°C, which resulted in finger temperatures sometimes lower than 10°C. Static work (standing or sitting) was typical for this type of work. The use of water was quite extensive which made the

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working environment very humid in general and resulted in frequent contact with wet surfaces and objects.

In Russia, the cold-related risk factors were observed 277 times at two sawmills by nine foremen (27 checklists were filled in) and 105 workers (250 checklists). In the original study design it was intended that all Russian observers should conduct the risk assessment procedure three times; however, some of the observers dropped out and only 88 of them filled in the checklist twice and 73 of them did it three times. Both sawmills worked on a three-shift regime. Around half of the employees were women; whereas it is unusual to find so many women working at sawmills in the western world. The cold risks were observed for outdoor work activities such as inspecting the delivered logs, sorting and marking both the floating logs and the processed timber. The working conditions were especially harsh for those working at a basin where the logs were sorted. Even if the workers had scheduled warm breaks, the management at one of the companies decided to cancel the breaks so that the lorries delivering the logs would not need to wait in a queue. The ambient temperature was around –30°C that night and the night shift workers were not supposed to take breaks during the entire shift.

In Sweden, a total of 44 checklists were filled in at two construction companies (21 checklists), a road building company (4 checklists) and a district office of the National Board of Forestry in the Northern part of Sweden (19 checklists). Both the workers (13) and foremen (5) at these companies observed the cold-related risk factors. The construction workers carried out their activities in an unheated indoor and/or cold outdoor environment. Two fifteen minute coffee breaks and a one-hour lunch break allowed workers to warm up during the working day. The workers could stop their activities if they thought the temperature was too low to operate outdoors (usually if the temperature was below –25°C). The workers at the road building company were exposed to cold intermittently. They spent most of the day in the heated cabins of vehicles. The exposure to cold usually occurred when vehicle maintenance work was carried out during such activities as clearing the road of snow, gritting, etc. The forestry workers usually spent about six hours out of an 8-hour working day outdoors. They spent one hour in the heated cabin (lunch and coffee breaks) and one hour for travel to and from the workplace by car and/or snow scooter. If the temperature was very low or it was very windy the workers would warm up in the heated cabins and take warm drinks every one or one and a half hour.

The authors provided identical instructions and training on how to carry out the cold risk assessment procedure to the observers in all four countries and prepared the needed material including the checklist itself in each country’s national language. Each observer was asked to perform the cold risk assessment procedure and to fill in the checklist independently of the previous times, if any were already carried out. The assessment procedure was performed various times per observer. The observers themselves chose the time when to conduct the assessment, as well as the duration of each observation. The observers were asked to assess the cold-related risk factors in relation to prevailing environmental conditions on the actual day of observations. There were several checklists filled in by the Nordic observers that had missing ratings for one or two cold-related risk factors.

From this point, persons using the checklist are referred to as subjects representing the above named groups (based on their occupation) of observers. Therefore the terms ‘observer’ and ‘subject’ are used interchangeably. In the case of foremen and occupational nurses, the observed work activity was carried out by someone else and not themselves, which was the case if the risk assessment procedure was performed by workers.

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2.2 Data analysis

The standard statistical package SPSS was used to analyse the results by a one sample and an independent-samples Pearson’s approximation to chi-square test ( 2) using the study-wide Type I error at =.05 level. Cramer’s measure of association (at =.05 level) was used to test the strength of the existing relationship between the various variables (the region where the checklist was filled in, the type of work, the ambient temperatures at the workplace and the sector that the company was representing) and the reported severity of a problem for a particular cold-related risk factor.

In order to determine whether the observers were choosing the problem severity alternatives for each cold-related factor at a greater-than-chance-level, a Pearson’s approximation to chi-square test ( 2) for one way classification was applied to the data at the significance level =.05. The independent samples Pearson’s 2 test with =.05 with a contingency table of dimensions three (no, slight or considerable problem) by two (Nordic and Russian) was applied to the data from the checklists filled in by the observers.

The data collected from the observers in the Nordic countries was divided into two groups according to whether the observed work activities were carried out indoors or outdoors. The indoor work group (N=48 checklists) comprised answers from Norwegian observers and the outdoor group from Finnish and Swedish observers (N=116 checklists). The independent-samples 2 test ( =.05) using a three (no, slight or considerable problem) by two (indoor or outdoor work) contingency table was applied to each risk factor of the checklists received from Nordic observers. However, the test could not be performed on the risk factor ‘use of PPE’ due to the fact that the expected cell frequency was less than 5 for too many cells (Kinnear & Gray, 2000).

Furthermore, the data in the group of outdoor workers from Finland and Sweden were divided according to the temperature indicated by the observers when they were assessing cold risks. This was repeated for the checklists received from the Russian observers. The temperature classification ranges were chosen as indicated in the temperature converting chart by the Canadian Centre for Occupational Health and Safety (1995). The category ‘cold’ comprised temperatures from 5 to –10°C, ‘very cold’ denoted temperatures from –11 to –26°C and ‘dangerously cold’ comprised temperatures from –27 to –40°C. As the nature of the checklist was purely observational, the observers were asked to indicate the temperature only if they knew it without engaging them in temperature measurements. In the Finnish and Swedish checklists, the temperature was specified by 103 observers with the following distribution among the categories: ‘cold’ received 43 checklists, ‘very cold’ received 59 checklists and ‘dangerously cold’ received 1 checklist. In the Russian checklists, the temperature was specified in all 277 checklists with the following distribution among the categories: ‘cold’ received 185 checklists, ‘very cold’ received 86 checklists and ‘dangerously cold’ received 6 checklists.

The independent samples Pearson’s 2 test ( =.05) with a three (no, slight or considerable problem) by two (cold and very cold) contingency table was applied to the group of Nordic (Finnish and Swedish) and Russian outdoor workers. In the case of the Nordic checklists, this test could not be applied to the following factors: ‘contact with cold surfaces’, ‘water/ liquids/ damp’, ‘protective clothing against cold’, ‘protection of extremities against cold’, ‘use of PPE’ and ‘insufficient lighting’ due to unfavourable rating distribution in the cells of the contingency table.

The types of activities in the outdoor work group of Finnish and Swedish observers were classified according to the International Standard Industrial Classification of All Economic Activities (United Nations, 1990) at the most detailed level (groups). The companies

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represented the following classes of economic activities: building of complete constructions or parts thereof; civil engineering with code 4520 (N=54 checklists filled in); cargo handling with code 6301 (N=28 checklists); forestry, logging and related service activities with code 0200 (N=19 checklists); manufacture of lifting and handling equipment with code 2915 (N=5); and other activities (N=10). The three latter groups were combined together under the group name ‘other activities’ (N=34) as the group samples were small and, furthermore, they represented various maintenance activities in different branches. The independent-samples 2

with a three (building, forestry and other activities) by three (no, slight or considerable problem) contingency table was applied to the data. However, this test was not applied to the following factors: ‘contact with cold surfaces’, ‘water/ liquids/ damp’, ‘protective clothing against cold’, ‘use of PPE’ and ‘insufficient lighting’ as too many cells of the contingency table had unfavourable rating distributions.

Finally, the two categories of problem severity (‘slight problem’ and ‘considerable problem’) were merged into one category (‘it is a problem’). The independent samples Pearson’s 2 test ( =.05) with a two (‘no problem’ and ‘it is a problem’) by two (cold and very cold) contingency table were applied to the groups of Nordic and Russian checklists separately.

3 ResultsWhen the results from the checklists filled in by the Nordic and Russian observers were compared, nine out of 13 cold-related risks factors were rated differently depending on whether the observer represented the Nordic or Russian group (see table 1). Therefore the results from Nordic and Russian observers were treated separately to test the influence of ambient temperatures (under which the work activities were observed) and the nature of the activity (indoor versus outdoor work) on the ratings of cold risk factors marked in the checklists.

The ratings for four cold-related risk factors: ‘cold air’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’ and ‘light work’ were rated similarly by Nordic and Russian observers. The one sample Pearson’s 2 test returned statistically significant results (at =.05 level) for the pooled data of these risk factors. Three cold-related risk factors were most often rated (‘cold air’ in 60.5% of cases, ‘contact with cold surfaces’ in 62.5% of cases and ‘water/ liquids/ damp’ in 54.3% of cases) as causing slight problems at the workplace. The risk factor ‘light work’ was most often marked (in 48.4% of all checklists) as non problematic.

Three cold-related risk factors (‘protection of extremities against cold’, ‘use of PPE’ and ‘long-term cold exposure’) from those rated differently by Nordic and Russian observers were rated most often (in 49.4%, 60.1% and 50.3% of cases respectively) as non problematic by the Nordic observers, while the Russians indicated most often (in 40.8%, 44.0% and 41.9% of cases respectively) that these factors were causing slight problems. The cold risk factor ‘slipperiness’ was marked most often (in 45.0% of cases) by Nordic subjects as causing slight problems, while Russian subjects rated it most often (in 40.1% of cases) as causing considerable problems.

Three risk factors (‘protective clothing against cold’, wind/ air movements and ‘highly varying workload’) had frequencies of ratings distributed along the categories of problem severity in such a manner that it produced statistically significant results. However, in the majority of the checklists from both Nordic and Russian groups the first risk factor was rated as non problematic (in 73.6% of Nordic and in 50.9% of Russian checklists) and the latter two as causing slight problems (in 61.3% and 51.4% respectively of Nordic and in 56.7% and 41.5% respectively of Russian checklists).

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Two cold-related risk factors (‘varying thermal environments’ and ‘insufficient lighting’) in the Russian group had frequency distributions that could have been defined by chance. In the Nordic group, these cold-related risk factors were most often rated as non problematic (in 49.7% and 64.1% of checklists respectively).

The association of problem severity and the observer’s region of origin was weak with Cramer’s V varying from 0.17 to 0.27 for the above named cold-related risk factors, except for the risk factors ‘long-term cold exposure’ and ‘insufficient lighting’ that had somewhat higher measures of association (0.44 and 0.35 respectively).

When the data from the Nordic checklists were broken into two groups depending on whether the work was carried out indoors or outdoors (see table 2), three cold-related risk factors were found to be rated differently. The cold-related risk factor ‘water/ liquids/ damp’ was rated most often as causing considerable problems (in 52.1% of checklists) in indoor work group, while it was most often (in 49.6% of checklists) rated as causing slight problems in the outdoor work group. Two risk factors (‘protection of extremities against cold’ and ‘long-term cold exposure’) were most often (in 68.8% and 57.9% of cases respectively) marked as causing slight problems for the indoor work group and as non problematic (in 59.5% and 55.0 % of cases respectively) for the outdoor work group. For the case of the above mentioned risk factors, the association of problem severity and the nature of the work was quite strong with Cramer’s V varying from 0.31 to 0.64.

When the groups of cold and very cold ambient temperatures for outdoor work were compared, three cold-related risk factors were rated differently (see table 3), if the distributions of problem severity ratings were taken into account. The risk factor ‘cold air’ had frequencies of ratings distributed along the categories of problem severity in such a manner that it produced statistically significant results, although the most common rating was ‘slight problem’ in both groups (51.2% of checklists in cold and in 74.6% very cold conditions). The cold-related risk factor ‘varying thermal environments’ was most often (in 65.0% of checklists) rated as non problematic under cold temperatures, while it was most often (in 44.6% of checklists) rated as ‘slight problem’ under very cold temperatures. The risk factor ‘slipperiness’ had the most ratings (64.3%) falling under the category ‘slight problems’ in the group of cold temperatures and the most ratings (46.4%) under the category ‘no problem’ in the group of very cold temperatures. The correlation between the problem severity categories and the ambient temperatures were weak (Cramer’s V was 0.28 and 0.29) for these risk factors, except for the risk factor ‘cold air’ (Cramer’s V=0.43).

According to the ratings marked in the checklists returned by Russian observers (see table 4), three cold-related risk factors (‘cold air’, ‘wind/air movements’ and ‘light work’) were rated differently depending whether the work was conducted under cold or very cold conditions. Two risk factors (‘cold air’ and ‘wind/air movements’) were rated most often as slightly problematic in both groups (59.5% and 57.8% of cases respectively under cold and 60.5% and 54.7% of cases respectively under very cold temperatures), but the differences between the rating distributions along the problem severity categories were statistically significant. In the case of the risk factor ‘light work’, the most often mentioned category was ‘no problem’ in the group of cold conditions (in 49.2% of cases) and ‘slight problem’ in the group of very cold conditions (in 50.0% of cases). The association of problem severity and the prevailing ambient temperatures was weak with Cramer’s V=0.17–0.26 for these risk factors.

A relationship between the branch of economic activity and problem severity was found to be statistically significant for the following risk factors: ‘cold air’ [ 2 (df=4, N=116) =26.76, Cramer’s V=0.34, p<.05], ‘protection of extremities against cold’ [ 2 (df=4, N=115) =48.05, Cramer’s V=0.45, p<.05], ‘long-term cold exposure’ [ 2 (df=4, N=109) =10.26, Cramer’s

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V=0.22, p<.05], ‘light work’ [ 2 (df=4, N=107) =10.99, Cramer’s V=0.23, p<.05], ‘highly varying workload’ [ 2 (df=4, N=110) =11.89, Cramer’s V=0.23, p<.05] and ‘varying thermal environments’ [ 2 (df=4, N=108) =15.46, Cramer’s V=0.27, p<.05].

Finally, when the two categories of problem severity were merged into one (‘it is a problem’), three cold-related risk factors (‘cold air’, ‘contact with cold surfaces’ and ‘light work’) were rated the same by Nordic and Russian observers. After the checklists were pooled together from the two groups, the first two factors had statistically significant distributions of ratings along the two categories, while the third one had insignificant ones. The two factors (‘cold air’ and ‘contact with cold surfaces’) were marked as causing problems in the majority (73.2% and 78.0% respectively) of checklists.

Two cold-related risk factors were rated differently by Nordic and Russian observers. According to the Nordic checklists, the risk factors ‘use of PPE’ (in 60.1% of checklists) and ‘insufficient lighting’ (in 64.1% of checklists) were not causing any problems. On the contrary, the ratings in the Russian checklists indicated that these factors were causing problems in 62.5% and 70.4% of cases respectively.

Two cold-related risk factors (‘wind/ air movements’ and ‘water/ liquids/ damp’) were rated differently according to the performed Pearson’s 2 test. However, the significant levels (p<.035 and p<.028 respectively) were just a bit lower than =.05. Therefore both factors were rated very similarly by both groups of observers. The two factors were marked most often as causing problems (in 73.0 % and 66.9% respectively of Nordic and in 81.6% and 76.5% respectively of Russian checklists). Two other factors (‘highly varying workload’ and ‘slipperiness’) were also most often rated as causing problems by both groups (in 63.5% and 60.4% respectively of Nordic and in 78.5% and 75.5% of Russian checklists), but the frequency percentages for these factors differed to a larger extent.

The ratings for four cold-related risk factors were not distributed across the two categories in a statistically significant manner for either Nordic or Russian groups. The risk factor ‘protective clothing against cold’ was most often rated as causing no problems in the Nordic checklists (73.6%), while three risk factors (‘protection of extremities against cold’, ‘long-term cold exposure’ and ‘varying thermal environments’) were rated most often as causing problems in the Russian checklists (in 69.3%, 88.1% and 72.9% of cases respectively).

4 DiscussionThe used checklist was observational in its nature and would indicate only potential areas where problems might exist. Furthermore, the ratings of experienced problems were self-reported by observers and could not be verified by other means. It should also be kept in mind that certain cold-related risk factors (‘cold air’, ‘protection of extremities against cold’, ‘long-term cold exposure’, ‘light work’, ‘highly varying workload’ and ‘varying thermal environments’) were found to be experienced by observers differently depending on the branch of economic activity that their workplace represented.

Slipperiness was found to be a problem at the workplace in both regions: Nordic countries and north-western Russia; however, the Russian observers experienced it to be more acute, as it was rated as a problem more often and of a greater severity. Certain differences regarding the experienced slipperiness were reported in the Nordic checklists representing the outdoor work activities. According to the observers, it was a problem under cold temperatures, but it did not cause any inconvenience under very cold temperatures.

Cold air and contact with cold surfaces were rated the same by Nordic and Russian observers. The observers experienced them as slight problems. Wind/ air movements and interchange

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between light and heavy work were perceived by both groups of observers as slightly problematic, although to a higher extent by Russian observers.

The Nordic observers did not perceive lighting as insufficient, though Russian observers did when asked whether this cold-related risk factor was problematic or not. Exposure to water/ liquids/ damp was marked as slightly problematic in the observed workplaces with more frequent complaints among the Russian observers. This problem was characterised as considerable by the Nordic indoor workers (in the fish factories).

Unexpectedly, the majority of observers thought that the protective clothing against cold provided in the workplaces was sufficient. This is especially surprising in the case of the Russian observers as the majority of them were using their own old clothes that they would not use in their private lives any more. On the other hand, Aptel (1988) found that the workers (exposed to artificial cold between –30 and +10ºC) were able to evaluate their own needs in thermal clothing insulation with sufficient accuracy if the required clothing insulation (IREQ) was under 1.50 clo. Furthermore, whenever it was possible, the workers preferred to wear thermal clothing insulation that provided them with thermal comfort.

In general, the majority of Nordic observers were satisfied with the level of extremity protection provided at the workplace, while the Russians claimed it to be partially insufficient. However, in the group of indoor Nordic workers it was most often mentioned that protection of extremities against cold was fairly good rather than sufficient. It should be taken into account that cold stress can be perceived very individually. For example, Hammarskjöld et al. (1992) found that ten carpenters perceived the cooling of the hand (after being exposure to moderate cold for one hour) very individually and the sensation of cold exposure was rated from ‘neither warm nor cold’ to ‘very, very cold’.

The majority of Nordic observers thought that it was easy to integrate protection against cold with personal protective devices so that they did not interfere with the performed work activities, while Russian observers experienced it as somewhat difficult.

In the checklists returned by Nordic observers it was most often marked that long-term cold exposure (continuously for more than two hours) was not a hazard at their workplaces, while Russian observers marked it most often as problematic. This could be explained by a more generous policy regarding warm-up breaks in the Nordic countries compared to the observed companies in north-western Russia. Interestingly the Nordic indoor workers had marked it as slightly problematic compared to the ‘no problem’ appearing most often in the checklists evaluating outdoor working conditions.

In general, light work such as, for example, standing while measuring or monitoring, was not a source of cold-related problems in the observed workplaces. However, according to the Russian observers it became somewhat of a problem if the work was to be carried out under very cold temperatures.

In general, frequent moving between indoor and outdoor conditions (from warm to cold environments) was judged as causing no problems at the observed workplaces. However, the majority of Russian observers would answer that it is a problem when asked whether this cold-related risk factor was problematic or not while not being required to specify how severe the problem was. It was also most often mentioned as slightly problematic in the majority of Nordic checklists representing outdoor work under very cold conditions.

The results reported in this study are similar to the ones reported by Gavhet et al. (1999a), who conducted a questionnaire study among harbour workers, mast workers, telecommunication technicians and customs personnel (43 respondents). The majority of the respondents (84%) indicated that cold air and wind was a problem at their workplaces. The

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reported sensations of cold hands and feet during the working day were attributed to the insufficient insulation provided by gloves and shoes. Only half of the respondents in their study were satisfied with their outdoor clothes (outer shell). Slipperiness was another common problem. These finding were supported by the field study of eight mast workers during maintenance and reparation activities (Gavhed et al., 1999b). Six workers reported that they were bothered by cold, and five indicated that they were bothered by wind. Their measured skin temperatures during the course of the day were as low as 6–14ºC for hands and 10ºC for toes.

In a study of cold working conditions at 13 dairy farms in Sweden, where 20 farmers served as subjects (Gavhed et al, 2002), it was reported that farmers experienced cold as a minor problem in farms with non-insulated loose housing barns. The typical climate in the milking parlours could be characterised as low air temperature, high humidity, moisture, frequent draughts and low surface temperatures. During milking, hands and fingers often became cold: hands were often 20–25ºC and fingers 6–9ºC at the end of milking period. In many cases, foot and toe temperatures dropped to unacceptably low temperatures. Cotton, which absorbs moisture and water well, was a very common material in garments worn by the farmers. A Finnish study of cold working environments on dairy farms (Tuure, 2003) studied two climatic factors: air temperature and air velocity. The author reported that the main problem was large temperature fluctuations encountered between the various workplaces occupied during a work cycle. This made it difficult to dress appropriately and led easily to both excessive and insufficient thermal clothing insulation.

In summary, the majority of the cold-related risk factors were rated differently by Nordic and Russian observers in term of either the chosen severity of the problem (‘no problem’, ‘slight problem’ or ‘considerable problem’) or the frequencies of ratings along these categories. Five factors (‘cold air’, ‘wind/ air movements’, ‘contact with cold surfaces’, ‘water/ liquids/ damp’ and ‘highly varying workload’) were most often rated as slightly problematic and two factors (‘protective clothing against cold’ and ‘light work’) as causing no problems by both groups. The remaining six factors (‘protection of extremities against cold’, ‘use of PPE’, ‘long-term cold exposure’, ‘varying thermal environments’, ‘slipperiness’ and ‘insufficient lighting’) were rated differently by Nordic and Russian observers, and the latter indicated less favourable situations at the observed workplaces. Only a few factors had different ratings if various variables (nature of work, ambient temperatures and sector of economic activities) were taken into account.

Acknowledgments This study was supported by the European Regional Development Fund (Barents Interreg IIA Program) and The Swedish Institute. We would like to thank all of the observers who participated in the study. Our thanks also go to research engineers Tanja Risikko and Anita Hicks, educational trainer Liisa Hänninen and trainer Maire Huurre from the Cold Work Action Program of the Finnish Institute of Occupational Health, Finland; dr. Kalev Kuklane from the Thermal Environment Laboratory, Department of Design Sciences, Lund Technical University, Sweden; managing director Arvid Påsche and senior engineer Bård Holand from Thelma AS, Norway for their contributions to the study.

LiteratureAptel M. Comparison between required clothing insulation and that actually worn by workers

exposed to artificial cold. Applied Ergonomics 1988; 19(4): 301–5.

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Canadian Centre for Occupational Health and Safety. Cold weather worker's safety guide. Hamilton: The Centre (CCOHS); 1995.

Enander A. Performance and sensory aspects of work in cold environments: a review. Ergonomics 1984; 27(4): 365–78.

Gavhed D, Kuklane K, Karlsson E, Holmér I. En pilotstudie om arbete i kyla - frågeundersökning och fältstudie (in Swedish). Stockholm: Arbetslivsinstitutet; 1999a. Report 4.

Gavhed D, Kuklane K, Karlsson E, Holmér I. Mastarbete i kyla (in Swedish). Stockholm: Arbetslivsinstitutet; 1999b. Report 22.

Gavhed D, Fredriksson K, Kuklane K, Holmér I, Norén O. Arbete i kyla i mjölkproduktionsanläggningar. Kartläggning och study av termiska arbetsmiljöproblem (in Swedish). Uppsala: Swedish Institute of Agricultural and Environmental Engineering; 2002. Report 290.

Giedraityt L, Mäkinen TM, Holmér I, Hassi J. The field testing of an observational checklist for the assessment of cold-related risk factors. Int J Circumpolar Health 2005; manuscript accepted for publication.

Hammarskjöld E, Harms-Ringdahl K, Ekholm J. Reproducibility of carpenters’ work after cold exposure. Int J Industrial Ergonomics 1992; 9(3): 195–204.

Hassi J, Juopperi K, Remes J, Rintamäki H, Näyhä S, Ervasti O, et al. FINRISKI'97 Kylmäaltistusalaotos. Tutkimus suomalaisten kylmäaltistuksesta, -haitoista ja kylmältä suojautumisen tavoista. Tutkimuksen toteutus ja perustaulukot (in Finnish). Oulu: Finnish Institute of Occupational Health; 1998. Report 4.

Holmér I, Granberg P-O, Dahlstrom G. Cold environments and cold work. In: Stellman JM, editor. Encyclopaedia of occupational health and safety. Geneva: ILO; 1998. p.4229–43.

Juopperi K, Hassi J, Risikko T, Hussi T, Ahonen G. Additional personnel costs in the construction industry occasioned by cold conditions. From theory to practice. Oulu: Finnish Institute of Occupational Health, Cold Work Action Program; 2000. Report A2.

Kinnear PR, Gray CD. SPSS for Windows made simple: release 10. Hove: Psychology; 2000. Pekkarinen A. Occupational accidents occurring in different physical environments with

particular reference to indoor and outdoor work. Oulu: University of Oulu; 1994. Doctoral thesis.

Ramsey JD, Burford CL, Beshir MY, Jensen, RC. Effects of workplace thermal conditions on safe work behaviour. J Safety Research 1983; 14(3): 105–14.

Statistics Sweden. The work environment 1999. Statistical bulletin. AM 68 SM 0001. Stockholm: Statistics Sweden; 2000.

Statistics Sweden. The work environment 2001. Statistical bulletin. AM 68 SM 0201. Stockholm: Statistics Sweden; 2002.

Statistics Sweden. Work-related disorders. Statistical bulletin. AM 43 SM 0501. Stockholm: Statistics Sweden; 2005.

Tuure V-M. Cold working environments on diary farms in Finland. Int J Circumpolar Health 2003; 62(2): 190–203.

United Nations. International standard industrial classification of all economic activities. New York: United Nations; 1990.

12

Tabl

e 1.

The

per

cent

age

of ra

tings

for a

cer

tain

risk

fact

or a

s ind

icat

ed b

y ob

serv

ers i

n th

e N

ordi

c (N

var

ies)

and

Rus

sian

(N=2

77) c

heck

lists

1 .

Nor

dic

coun

trie

s N

orth

-wes

tern

Rus

sia

Seve

rity

of a

pro

blem

2Se

verit

y of

a p

robl

em2

Com

paris

on b

etw

een

the

two

grou

ps a

t =.

05R

isk

fact

or

1 2

3 N

1 2

3 2 (d

f=2)

Cra

mer

’s V

N

1 C

old

air

25.8

61.3

12.9

16

3 27

.4

59.9

12.7

N

S 44

0

2 W

ind/

air

mov

emen

ts27

.061

.311

.7

163

18.4

56

.724

.9

12.8

9 .1

7 44

0

3 C

onta

ct w

ith c

old

surf

aces

21

.5

66.9

11.6

16

3 22

.4

59.9

17.7

N

S 44

0

4 W

ater

/ liq

uids

/ dam

p 33

.1

49.1

17.8

16

3 23

.5

57.4

19.1

N

S 44

0

5 Pr

otec

tive

clot

hing

aga

inst

col

d 73

.620

.2

6.2

163

50.9

38.3

10

.8

21.9

6 .2

2 44

0

6 Pr

otec

tion

of e

xtre

miti

es a

gain

st c

old

49.4

39.0

11

.6

164

30.7

40

.828

.5

22.9

4 .2

3 44

1

7 U

se o

f PPE

60

.136

.8

3.1

163

37.5

44

.018

.5

31.6

7 .2

7 44

0

O

ther

pro

blem

s:

8

Long

-term

col

d ex

posu

re

50.3

33.3

16

.4

147

11.9

41

.946

.2

81.9

2 .4

4 42

4

9 Li

ght w

ork

55.1

36.0

8.

9 13

6 45

.138

.3

16.6

N

S 41

3

10

Hig

hly

vary

ing

wor

kloa

d 36

.5

51.4

12.1

14

8 21

.7

41.5

36.8

30

.76

.26

425

11

Var

ying

ther

mal

env

ironm

ents

49

.734

.5

15.8

14

5 27

.1

38.6

34

.3

25.9

3 .2

4 42

2

12

Slip

perin

ess

39.6

45

.015

.4

149

24.5

35

.4

40.1

28.3

5 .2

5 42

6

13

Insu

ffic

ient

ligh

ting

64.1

26.2

9.

7 14

5 29

.6

38.6

31

.8

50.9

0 .3

5 42

2

1 The

one

sam

ple

Pear

son’

s 2 (d

f=2,

N v

arie

s de

pend

ing

on th

e gr

oup

and

risk

fact

or) w

as c

alcu

late

d (a

t =.

05) f

or e

ach

cold

-rel

ated

risk

fa

ctor

in th

e N

ordi

c an

d R

ussi

an g

roup

s se

para

tely

. The

freq

uenc

y di

strib

utio

ns o

f pro

blem

sev

erity

cat

egor

ies

alon

g th

e pa

rticu

lar f

acto

r w

ere

stat

istic

ally

sign

ifica

nt e

xcep

t for

the

risk

fact

ors o

f ‘va

ryin

g th

erm

al e

nviro

nmen

ts’ a

nd ‘i

nsuf

ficie

nt li

ghtin

g’ in

the

Rus

sian

gro

up.

2C

ateg

ory

‘1’ s

tand

s for

‘No

prob

lem

’, ca

tego

ry ‘2

’ sta

nds f

or ‘S

light

pro

blem

’ and

cat

egor

y ‘3

’ sta

nds f

or ‘C

onsi

dera

ble

prob

lem

’.

13

Tabl

e 2.

The

per

cent

age

of ra

tings

for a

cer

tain

risk

fact

or a

s ind

icat

ed in

the

Nor

weg

ian

chec

klis

ts (N

var

ies)

repr

esen

ting

indo

or w

ork

and

in

the

Finn

ish

and

Swed

ish

chec

klis

ts (N

var

ies)

repr

esen

ting

outd

oor w

ork1 .

Indo

or w

ork

O

utdo

or w

ork

Se

verit

y of

a p

robl

em2

Seve

rity

of a

pro

blem

2C

ompa

rison

bet

wee

n th

e tw

o gr

oups

at

=.05

Ris

k fa

ctor

1 2

3 N

1 2

3 N

2 (df=

2) C

ram

er’s

VN

1 C

old

air

29.8

57.4

12.8

47

24

.1

63.0

12.9

11

6 N

S 16

3

2 W

ind/

air

mov

emen

ts33

.362

.54.

2 48

24

.3

60.9

14.8

11

5 N

S 16

3

3 C

onta

ct w

ith c

old

surf

aces

18

.8

60.4

20.8

48

22

.6

69.6

7.8

115

NS

163

4 W

ater

/ liq

uids

/ dam

p 0

47.9

52

.148

47

.0

49.6

3.4

115

67.5

2 .6

4 16

3

5 Pr

otec

tive

clot

hing

aga

inst

col

d 83

.316

.7

0 48

69

.621

.7

8.7

115

NS

163

6 Pr

otec

tion

of e

xtre

miti

es a

gain

st c

old

25.0

68

.86.

2 48

59

.526

.7

13.8

11

6 25

.20

.39

164

7 U

se o

f PPE

75

.025

.0

0 48

54

.041

.7

4.3

115

test

not

ava

ilabl

e 16

3

O

ther

pro

blem

s:

8 Lo

ng-te

rm c

old

expo

sure

36

.8

57.9

5.3

38

55.0

24.8

20

.2

109

14.9

2 .3

1 14

7

9 Li

ght w

ork

58.6

41.4

0

29

54.2

34.6

11

.2

107

NS

136

10

Hig

hly

vary

ing

wor

kloa

d 26

.3

65.8

7.9

38

40.0

46

.413

.6

110

NS

148

11

Var

ying

ther

mal

env

ironm

ents

48

.6

35.1

16

.3

37

50.0

34.3

15

.7

108

NS

145

12

Slip

perin

ess

44.7

42.1

13

.2

38

37.9

45

.916

.2

111

NS

149

13

Insu

ffic

ient

ligh

ting

66.7

22.2

11

.1

36

63.3

27.5

9.

2 10

9 N

S 14

5

1 The

one

sam

ple

Pear

son’

s 2 (

df=2

, N v

arie

s de

pend

ing

on th

e gr

oup

and

a ris

k fa

ctor

) w

as c

alcu

late

d (a

t =.

05)

for

each

col

d-re

late

d ris

k fa

ctor

for t

he in

door

and

out

door

wor

k gr

oups

sep

arat

ely.

The

freq

uenc

y di

strib

utio

ns o

f pro

blem

sev

erity

cat

egor

ies

alon

g th

e pa

rticu

lar f

acto

r w

ere

stat

istic

ally

sign

ifica

nt e

xcep

t for

the

risk

fact

or o

f ‘va

ryin

g th

erm

al e

nviro

nmen

ts’ i

n th

e in

door

wor

k gr

oup.

2C

ateg

ory

‘1’ s

tand

s for

‘No

prob

lem

’, ca

tego

ry ‘2

’ sta

nds f

or ‘S

light

pro

blem

’ and

cat

egor

y ‘3

’ sta

nds f

or ‘C

onsi

dera

ble

prob

lem

’.

14

Tabl

e 3.

The

per

cent

age

of ra

tings

for a

cer

tain

risk

fact

or a

s ind

icat

ed b

y Fi

nnis

h an

d Sw

edis

h ob

serv

ers o

f the

out

door

wor

k ac

tiviti

es u

nder

co

ld (f

rom

5 to

–10

°C, N

var

ies)

and

ver

y co

ld (f

rom

–11

to –

26°C

, N v

arie

s) a

mbi

ent t

empe

raur

es1 .

Col

d te

mpe

ratu

res

Ver

y co

ld te

mpe

ratu

res

Seve

rity

of a

pro

blem

2Se

verit

y of

a p

robl

em2

Com

paris

on b

etw

een

the

two

grou

ps a

t =.

05R

isk

fact

or

1 2

3 N

1 2

3 N

2 (df=

2) C

ram

er’s

VN

1 C

old

air

44.2

51.2

4.6

43

8.5

74.6

16.9

59

18

.78

.43

102

2 W

ind/

air

mov

emen

ts25

.667

.47.

0 43

23

.7

55.9

20.4

59

N

S 10

2

3 C

onta

ct w

ith c

old

surf

aces

16

.3

83.7

0 43

27

.1

59.3

13.6

59

te

st n

ot a

vaila

ble

102

4 W

ater

/ liq

uids

/ dam

p 48

.8

48.8

2.

4 43

45

.7

49.2

5.1

59

test

not

ava

ilabl

e 10

2

5 Pr

otec

tive

clot

hing

aga

inst

col

d 81

.418

.6

0 43

66

.125

.4

8.5

59

test

not

ava

ilabl

e 10

2

6 Pr

otec

tion

of e

xtre

miti

es a

gain

st c

old

74.4

25.6

0

43

54.2

32.2

13

.6

59

test

not

ava

ilabl

e 10

2

7 U

se o

f PPE

48

.8

51.2

0 43

55

.239

.7

5.1

58

test

not

ava

ilabl

e 10

1

O

ther

pro

blem

s:

8 Lo

ng-te

rm c

old

expo

sure

60

.022

.5

17.5

40

55

.425

.0

19.6

56

N

S 96

9 Li

ght w

ork

51.2

39.0

9.

8 41

54

.532

.7

12.8

55

N

S 96

10

Hig

hly

vary

ing

wor

kloa

d 48

.839

.0

12.2

41

35

.7

51.8

12.5

56

N

S 97

11

Var

ying

ther

mal

env

ironm

ents

65

.017

.5

17.5

40

42

.9

44.6

12.5

56

7.

75

.28

96

12

Slip

perin

ess

23.8

64

.311

.9

42

46.4

35.7

17

.9

56

7.98

.2

9 98

13

Insu

ffic

ient

ligh

ting

57.5

42.5

0

40

69.6

17.9

12

.5

56

test

not

ava

ilabl

e 96

1 The

one

sam

ple

Pear

son’

s 2 (d

f=2,

N v

arie

s dep

endi

ng o

n th

e gr

oup

and

a ris

k fa

ctor

) was

cal

cula

ted

(at

=.05

) for

eac

h co

ld-r

elat

ed ri

sk fa

ctor

in

eac

h gr

oup

(col

d or

ver

y co

ld w

orki

ng c

ondi

tions

) sep

arat

ely.

The

freq

uenc

y di

strib

utio

ns o

f pro

blem

seve

rity

cate

gorie

s alo

ng th

e pa

rticu

lar

fact

or w

ere

stat

istic

ally

sign

ifica

nt fo

r all

risk

fact

ors.

2C

ateg

ory

‘1’ s

tand

s for

‘No

prob

lem

’, ca

tego

ry ‘2

’ sta

nds f

or ‘S

light

pro

blem

’ and

cat

egor

y ‘3

’ sta

nds f

or ‘C

onsi

dera

ble

prob

lem

’.

15

Tabl

e 4.

The

per

cent

age

of ra

tings

for a

cer

tain

risk

fact

or a

s ind

icat

ed b

y R

ussi

an o

bser

vers

of t

he o

utdo

or w

ork

activ

ities

und

erco

ld (f

rom

5 to

–10

°C, N

=185

che

cklis

ts) a

nd v

ery

cold

(fro

m –

11 to

–26

°C, N

=86

chec

klis

ts) a

mbi

ent t

empe

raur

es1 .

Col

d te

mpe

ratu

res

Ver

y co

ld te

mpe

ratu

res

Seve

rity

of a

pro

blem

2 Se

verit

y of

a p

robl

em2

Com

paris

on b

etw

een

the

two

grou

ps a

t =.

05, N

=277

R

isk

fact

or

1 2

3 1

2 3

2 (df=

2) C

ram

er’s

V

1 C

old

air

33.5

59.5

7.0

16.3

60

.523

.2

18.9

2 .2

6

2 W

ind/

air

mov

emen

ts22

.257

.820

.0

10.5

54

.734

.8

9.72

.1

8

3 C

onta

ct w

ith c

old

surf

aces

21

.6

60.5

17.9

25

.6

58.1

16.3

N

S

4 W

ater

/ liq

uids

/ dam

p 23

.8

59.5

16.7

22

.1

53.5

24.4

N

S

5 Pr

otec

tive

clot

hing

aga

inst

col

d 51

.438

.9

9.7

51.2

39.5

9.

3 N

S

6 Pr

otec

tion

of e

xtre

miti

es a

gain

st c

old

29.7

42

.727

.6

33.7

37

.2

29.1

N

S

7 U

se o

f PPE

38

.9

44.3

16.8

36

.0

44.2

19.8

N

S

O

ther

pro

blem

s:

8 Lo

ng-te

rm c

old

expo

sure

13

.5

41.6

44

.99.

3 41

.9

48.8

NS

9 Li

ght w

ork

49.2

31.9

18

.9

37.2

50

.012

.8

8.27

.1

7

10

Hig

hly

vary

ing

wor

kloa

d 23

.8

38.4

37.8

17

.4

47.7

34.9

N

S

11

Var

ying

ther

mal

env

ironm

ents

27

.641

.6

30.8

25

.6

34.9

39

.5

NS

12

Slip

perin

ess

24.9

35

.7

39.4

24.4

36

.0

39.6

N

S

13

Insu

ffic

ient

ligh

ting

30.8

38

.4

30.8

27

.9

39.5

32

.6

NS

1 The

one

sam

ple

Pear

son’

s 2 (d

f=2,

N=1

85 o

r N=8

6 de

pend

ing

on th

e gr

oup)

was

cal

cula

ted

(at

=.05

) for

eac

h co

ld-r

elat

ed ri

sk

fact

or in

eac

h gr

oup

(col

d or

ver

y co

ld w

orki

ng c

ondi

tions

) sep

arat

ely.

The

freq

uenc

y di

strib

utio

ns o

f pro

blem

sev

erity

cat

egor

ies

alon

g th

e pa

rticu

lar

fact

or w

ere

stat

istic

ally

sig

nific

ant e

xcep

t for

the

risk

fact

or d

enot

ed b

y th

e nu

mbe

r 13

(in

bot

h gr

oups

) an

d fa

ctor

s den

oted

by

the

num

bers

6, 1

1 an

d 12

in th

e gr

oup

of v

ery

cold

con

ditio

ns.

2C

ateg

ory

‘1’ s

tand

s for

‘No

prob

lem

’, ca

tego

ry ‘2

’ sta

nds f

or ‘S

light

pro

blem

’ and

cat

egor

y ‘3

’ sta

nds f

or ‘C

onsi

dera

ble

prob

lem

’.

Reprinted from: International Journal of Occupational Safety and Ergonomics 2001, 7 (2), 135–148

PAPER V

Documents

Identification and validation of risk factors in cold work