Sean Chester MPH: Occupational Hygiene (Wits)

Registered Occupational Hygienist (SAIOH)

“Whole Body Vibration” is the mechanical vibration that, when transmitted to the whole body, entails risks to the health and safety of workers, in particular lower-back

morbidity and trauma of the spine”.

CSAO

For personnel operating heavy equipment, whole-body vibration (WBV) is transmitted

through supporting surfaces such as the feet of a standing person, the buttocks of a seated person, and the supporting areas of a reclining

person. Human response to WBV depends on the frequency of the vibration (measured in Hertz units— Hz), acceleration (or magnitude in metres per seconds squared) of the vibration,

duration of exposure to the vibration

With short-term exposure to vibration in the 2-20 Hz range at 1 m.s-2 (vibration magnitude) one can feel several different symptoms such as abdominal and chest pain, headaches, nausea, and loss of balance.

Long-term exposure to WBV can cause serious

health problems, particularly with the spine: degenerative spinal changes lumbar scoliosis disc disease

degenerative disorders of the spine herniated discs disorders of the gastrointestinal system.

Occupational Health and Safety Act, 1993 – Section 8

Directive 2002/44/EC of the European Parliament and of the Council of 25 June 2002HSE - The Control of Vibration at Work Regulations, 2005

EAV = 0.5 m/s²

ELV = 1.15 m/s²

A Qualitative Assessment of the WBV to which Tractor Drivers operating in the Ethekwini Municipal District are exposed

EC and HSE Legislation HSE Information Sheets EU Good Practise Guide

Occupational Health Clinics for Ontario Workers Inc - WBV Document

ISO 2631/1: Mechanical vibration and shock - Evaluation of Human Exposure to Whole-Body Vibration, 2001

British Standard 6841: Measurement and evaluation of human exposure to whole - body vibration, 1987

BUT, found that the qualitative information and methodologies contained in the EC directive and the HSE Regulations most

useful

There are four active tractors

Drivers are primarily involved in lawn

mowing within the Pinetown Municipal District

verges and open spaces (parks or sports fields)

driving on roads and in the field.

SHIFTS 07h30 - 15h30

Tea 10h00 - 10h20

Lunch 12h00 - 12h30

Driving 07h40 - 14h50

Return to depot for washing of the mower & tractor

• Fields at distance require driving on the main roads • Road driving “reportedly” generates more

vibration (Speed + Raised mower equipment )• The raising of the mower equipment during

transit between spaces increases discomfort during driving

• Drivers were provided with “kidney” belts for use while mowing

• Drivers also report less WBV without mowing equipment attached

CIVIC CENTRE

Road: 7H40 - 8H00: 20 Minutes Field: 15 mins Road (Maduza): 5 Mins Field: 15 Mins Verges to Leslie Park : 10 mins Leslie Park: 1 Hour Road to Leeds Crescent: 10 mins Leeds Park: 1 Hour Road: 15 mins to Stapleton (open space) Stapleton open space: 1 hour Road to Clover Park: 15 mins Clover Park: 20 Minutes Glen Park: (opposite Clover Park) 15 mins Back to Depot: Road 30 Minutes Total Road: 95 mins Total Field: 260 mins Total Driving: 355 min (approx 6 hrs)

CHATSWORTH

Road: 1 hour (07H40 - 08H40) Fields (open space, park & sports field): 08H40 - 10h00 (break for Tea) 10H20 - 12h00 (break for lunch) 12H30 - 14h00 (leave for Depot) Road: 14h00 - 14h50

Total Road: 110 mins Total Field: 270 mins

Total Driving: 380 min (6.5 hrs)

• “Reportedly” 15 Years Old• 1975 - 1983• Oil leaks

• Clutch is hard to depress• Diesel gauges do not work• Engine cover rattles loudly• Seat - arm rests are too low

- tension cannot be adjusted - position mechanism is broken - worn (5 years old)

• Has power steering• No roof

• Two of these tractors • “Reportedly” 2 years old • 1975 - 1983 •Seat - tension works well • - Drivers unaware of use and

adjustment of this

mechanism - slide was jammed - arm rests are raised

• Roof & Power Steering

ACUTE HEALTH ISSUES

Lower back pain Kidney and abdominal pain Knee and leg pain No head aches Chest pains No nausea Loss balance

Cramps during precision tasks

No shortness of breath No influence on speech

CHRONIC HEALTH ISSUES Disc displacement has

occurred Unsure about degenerative

diseases of the spine and intervertebral disc displacement

Unsure about herniated disks Disorders of the gastro-

intestinal system No issues relating to Uro-

genital systems Loss of sex drive? Kidney pain

EU Good Practice Guide (2006)

TRACTOR & TERRAIN Outdated equipmentSeat adjustment and isolationmechanisms faulty & oldNo arm rests on MF265 Control gear is faultyMower increases WBVTerrain is variable, unevensurfaces in parks and verges;road surfaces are sometimes an issue Large shocks are experienced in twisted posturesBallast is installed in the workshop

DRIVERS

15 - 26 years driving Already affected by WBV Maintain poor postures Drive too fast on roads?

Inadequate medical surveillance programme Inadequate information & training on WBV and controls Support for, and use of kidney belts

Comparison of vibration values for vehicles researched in Literature

Occupational Health Clinics for Ontario Workers Inc.

EU Good Practice Guide (2006)

Simply look on the graph for the A(8) line at or just above where your vibration magnitude value (kaw)max

and exposure time lines meet (the factor k is either 1.4 for the x- and y-axes or 1.0 for the z-axis i.e. vertical direction).

EU Good Practice Guide (2006)

Source Predicted EmissionsAve. Exposure QualitativeData Duration Results(m/s2) (Minutes)

OHC for Ontario Workers

EU Directive

HSE

0.6, 1.1 & 1.7

0.3 - 1.4

Significantly > 0.5

Total Road: 103.5

Total Field: 265

(approx 4.5 hrs)

Total Driving: 367

(approx 6 hrs)

Caution: Health Effects are predicted

Prohibit / Limit the use of Kidney BeltsVerify Qualitative data with accelerometer monitoringEstablish a comprehensive health surveillance

programmeScrutinise vibration emission data before purchasing

equipment Maintain equipment in sound working order. This includes suspension system and correct tyre pressure

Retrofit MF 265s with seats incorporating hydraulic dampers and shock absorbers specifically built to reduce WBVTrain operators to adjust seats correctly Check, lubricate and maintain seat suspensions.

Establish who is responsible for managing the control of risk from exposure to WBV or shock. Reduce travel speed over all terrain types.

Maintain Road and park surfaces as a broader component of the WBV programme. Encourage regular breaks or task rotation (said with

caution). Provide information and training for operators on how

to minimise exposure to WBV and shock and how to recognise and report symptoms. Ensure that employees installing ballast plates are

properly trained.