Kurhade G, Kurhade A, Phatak MS, Farid Y. A Cross Sectional Study of Respiratory Symptoms and Spirometry in Adults Exposed to Bio aerosol in Vegetable Market in India. Int J Health

Occupational Exposure to Vegetable Dust affects Lung Functions

58 January 2013 International Journal of Health and Rehabilitation Sciences Volume 2 Issue 1

ORIGINAL RESEARCH A Cross Sectional Study of Respiratory Symptoms

and Spirometry in Adults Exposed to Bio aerosol

in Vegetable Market in India

Geeta Kurhade, Arvind Kurhade, Mrunal S Phatak, Youssef Farid Dr. Geeta Kurhade is Senior

Lecturer, Physiology unit,

Department of Preclinical

Science, University of West

Indies, St Augustine campus,

Trinidad and Tobago.

Dr. Arvind Kurhade is

Lecturer, Microbiology Unit,

Department of Para Clinical

Sciences, EWMSC, Mt.Hope,

University of West Indies, St

Augustine campus, Trinidad

and Tobago.

Dr. Mrunal S Phatak is

Professor and Head,

Department of Physiology,

IGGMC, Nagpur,

Maharashtra, India.

Dr. Youssef Farid is

Lecturer, Physiology unit,

Department of Preclinical

Science, University of West

Indies, St Augustine campus,

Trinidad and Tobago.

Corresponding Author:

Dr. Geeta Kurhade

E-mail:

[email protected]

www.ijhrs.com

Background: Bio aerosol pollution of workplace environment mainly affects the airways

and mucous membrane many times culminating in respiratory distress and COPD. This

causes increased morbidity and loss of work hours for the affected individuals.

Objective: To estimate the prevalence of respiratory symptoms and lung functions in

individuals exposed to mixed bio aerosols in a vegetable market and to test the association of

age of an individual with various lung function tests.

Materials and Methods: Bio aerosol characteristics of air in the market were analysed by

Reusable Aluminium Two Stage Viable Anderson Cascade Impactor. Spirometry with

American Thoracic Society (ATS) standards was done in non-smoker 640 individuals; 210

individuals exposed to dust and 430 individuals living around the same area but not exposed

to dust. According to age 2 groups were made. Group A (20-30years) having 110 exposed

and 220 unexposed individuals .Group B (31-40years) having 100 exposed and 210

unexposed individuals. Spirometry results were compared between 2 groups using SPSS

software version 16.0.2 for student’s t test and F test to test the statistical significance at

p < 0.05 and confidence interval of 95%.

Results: The bio aerosol analysis revealed high level of polluting microbial components. In

exposed individuals compared to unexposed individuals prevalence of respiratory symptoms

was significantly high (p<0.05) and spirometry demonstrated significant reduction in Forced

Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), Forced Expiratory

Flow at 25% - 75% Vital Capacity (25% -75%) and Peak Expiratory Flow Rate

(PEFR).There was significant positive correlation between age and decrease in all the

recorded spirometry parameters (p<0.05).

Conclusion: Occupational exposure to mixed organic dust is associated with significantly

higher respiratory symptoms and decreased spirometric values necessitating medical

attention. So there is need of preventive measures and health education in this population.

Keywords: Environmental vegetable dust, Bio aerosol, Occupational exposure, Respiratory

symptoms, Spirometry



INTRODUCTION Occupational exposure to vegetable dust

with a high quantity of inhalable particles and its

effect on respiratory system has been

investigated in many populations 1-6

. Louis

Pasteur described the first measurements of

airborne microorganisms in 1861. A century

later, the inhalation of spores from thermophilic

microorganisms was shown to induce attacks of

farmers' lung in patients with this disease, while

endotoxins originating from Gram-negative

bacteria were identified as causal agents for

byssinosis in cotton workers. Further

epidemiological and toxicological studies have

demonstrated inflammatory, respiratory, and

pathogenic effects following exposure to bio

aerosols. Exposure assessment is often

confounded by the diversity of bio aerosol

agents in the environment 7.

The bio load of such dust could include

contaminants such as bacteria, fungi, pollen,

insects and all grades of respiratory tract

infection may follow the long term exposure.

Constant inflammatory states in the lung may

eventually lead to tissue damage of smallest

bronchi and bronchioles followed by fibrosis,

with increased thickness of the walls resulting in

changes in airways resistance to produce

obstruction in the airways and respiratory

deficit7.

Although the World Health

Organisation has predicted that occupational

respiratory diseases will become the third

leading cause of death by 2020 8, little work has

been done to examine this problem in India

known for its agriculture based economy where

the population is more exposed to polluted,

mixed organic dust and only few studies have

characterized the composition of the microbial

flora of such dust9.

According to the ministry of health and

family welfare, India has 17 million persons

living with chronic obstructive pulmonary

disease, a number that is estimated to rise to 22

million by 201610

.The Out Patient Department

of three Medical institutions in the Nagpur,

Central India had noticeable number of patients

with different respiratory complaints and history

of occupation in the overcrowded busy

vegetable market. The dust in this particular

market place is a mixture of raw vegetable

material including tea, coffee, spices, grains and

other components such as wet and dry animal

excreta, fungi, bacteria the Inhalation of which

may expose workers to risks from infection,

allergy and may cause a variety of harmful

effects in the airways.

Given the significant number of

patients with respiratory complaints presenting

to the local hospitals from the vegetable ‘Cotton

market’, Nagpur; we conducted this cross

sectional study of the respiratory symptoms and

lung function of persons working there and

compared the results with biometrically matched

controls who were visiting and only occasionally

exposed to mixed bio aerosols. We also

evaluated the air quality of the market in terms

of microbes and suspended particulate matter

(SPM). The lung function tests were associated

with age of subjects.

MATERIALS AND METHODS

In this cross sectional study conducted

in summer 2009; after obtaining clearance from

Institutional Ethics committee, total 680 male

subjects in 20-40 years age group were

registered. Informed written consent was taken

from all the subjects. Those with history of

smoking, cardiovascular disease, beta blocker

usage; and those with poor cooperation and

those with unacceptable spirogram were

excluded. Finally 640 subjects completed the

study which included 210 subjects exposed to

mixed vegetable dust for 2-18 years and 430

age, weight and height matched randomly

selected unexposed controls using the same

exclusion criteria. No participants had any

contraindication for spirometry.

Air sampling and bio load analysis of the air Air sampling was done weekly for five

months during the months of March to July 2009

using reusable aluminium two stage Viable

Andersen Cascade Impactor (The Thermo

Scientific company, USA, Thermo Fisher

Scientific India Pvt. Ltd, Pawai, Mumbai , India) 11-12

operated at one meter height from the

ground extramurally for two minutes at the site.

The instrument was sterilised before use and

calibrated for flow rate at 28.3L/min.



Microbe’s analysis The microbiology department of

Government Medical College, Nagpur processed

and studied the biotic components. Tryptone

Glucose Yeast Extract (TGYE), Agar medium

plate was used on the upper stage of the sampler

for the enumeration and isolation of total viable

types of bacterial population present in air.

Eosin Methylene Blue (EMB) Agar Medium (Hi

Media) media plate was used on lower stage of

the sampler for gram- negative enteric bacteria

to find out the inhalable amount. Processing of

samples was done by serial dilution technique

(10-2 to 10-4) to get only a few cells per ml.

One ml of inoculums from each dilution poured

onto sterilized Petri plates of respective media

(TGYE & EMB) at 45 oC by using Pour plate

technique13

. Then plates were incubated at 37 ±

2oC for 24 to 48 hours. Total 83 types of isolates

were identified.

The level of bacterial contamination of

air is usually expressed in terms of number of

bacteria-carrying particles per m3 (bcp/m

3) or the

bio load (B). B is calculated from the following

equation:

B= 1000N/ RT

The colony-forming units are counted on the

sample plate, N is the number of colonies

counted on the sample plate, T is the duration of

the test in minutes and R is the air-sampling rate

in litres /min. Dose-response relationships have

not been established for most biological agents

and knowledge about threshold values is

sparse14

.

Common respiratory symptoms

Common respiratory symptoms were

recorded by simple interview using

questionnaire derived from other studies 15-16

and

results tabulated. One section of questionnaire

was completely devised to explore the frequency

and duration of exposure based on the detailed

history of the actual job. Spirometry was

performed in all subjects and controls from eight

to ten a.m.,in standing position and during the

same season using a calibrated Spirolab II

spirometer (MIR,Rome, Italy) following

American Thoracic Society (ATS) criteria 17

.Each individual repeated the maneuver three

to eight times to obtain 3 acceptable spirogram.

The spirogram with the highest value was used

for statistical analysis and interpretation.

Statistical Analysis The mean ± SD of predicted values with actual

values of spirometry results were compared

between the two age groups of subjects –with

each other and respective controls, using SPSS

version 16.0.2 software by application of

Student’s t test and F test. A 2-sided P value of

.05, with a confidence interval of 95%, was the

criterion for statistical significance. For some

data analysis X cell T Test and Free p-value

calculator for the student t test were used for

analysis18

.

RESULTS

Air analysis

The average suspended particulate

matter (SPM) and particulate matter (PM10)

levels exceeded Central Pollution Control Board

(CPCB) standards; 290 µg/m3 and 100 µg/m

3, as

compared to National Ambient Air Quality

Standards, 140 µg/m3 and 60 µg/m

3 respectively.

The pollution on this basis was labelled as

moderate 19

.

Table 1 Demographic Characteristics (mean ± SD)

Age

groups

Study groups Age (years) Height (cms) Weight (Kg) BMI kg/m2 Years

of

expos

Cont Subj Cont Subj P

val# Cont Subj

P

val# Cont Subj

P

val# Cont Subj

P

val# Subj

20-30

years 220 110

26.16

±1.91

24.18

±3.09 >0.05‡

171.27

± 5.53

170.63

± 3.29 >0.05‡

63.8

±4.84

64.27

±4.83 >0.05‡

21.87

±1.21

22.24

±1.23 >0.05‡

5.63

± 2.94

31-40

Years 210 100

34.21

±2.25

33.7

±2.54 >0.05‡

166.85

± 3.54

164.5

± 4.11 >0.05‡

63.35

±6.81

62.1

±5.17 >0.05‡

22.70

±1.20

22.83

±1.11 >0.05‡

12.6

± 3.43

Cont – Controls (n = 430), Subj – Subjects (n = 210), expos – exposure ,#- Student’s t test, ‡- Not Significant p>0.05



Total mean viable bacterial load was

1995.66 ± 1184.555 cfu/m3. Gram positive rod,

cocci, pleomorphic, Gram negative rod, vibrio,

filamentous, Gram negative/ positive

coccobacilli were grown. Filamentous bacteria

were maximum 38% followed by gram negative

rods (28%) and gram positive bacilli (23%).

The microbes culture demonstrated

presence of Citrobacter & Proteus including

Citrobacter freundii, Erwinia herbicola and

Escherichia coli, along with other gram-negative

bacteria i.e. Chryseomonas luteloa,.

Acinetobacter calcoaceticus, Pseudomonas

mendocina, Pseudomonas multophila and

Serratia plymuthica , Yersinia intermedia,

Escherichia (E. Coli), Providencia were also

reported. In one sewage water sample

Escherichia Coli, Vibrio carchariae, Vibrio.

diazotrophicus, Vibrio Metshnikovii were

demonstrated. Fungus reported were Aspergillus

fumigatus and Aspergillus flavus.

Spirometry Study group

The total six hundred and forty subjects

were classified in two groups.

Group A (20-30 years) comprised of

110 subjects (mean age 24.18±3.09

years) and 220 controls mean age

(26.16±1.91 years).

Group B (31-40 years) included 100

subjects (33.7±2.54 years) and 210

controls mean age (34.21±2.25 years).

Demographic characteristics of the groups

A and B of test group and controls matched for

age weight and height showed no significant

difference (Table 1). The mean duration of

exposure (directly working with or indirectly

passively exposed) in group A was 5.63 ± 2.94

years and that in group B 12.6 ± 3.43 years.

The prevalence of respiratory symptoms

in test group as compared to control group are

shown in Table 2. It is much higher and

statistically significant.

The results of spirometry in both the

groups A and B of subjects exposed to mixed

dust and in unexposed controls are shown in

Table 3. The results were compared in terms of

percent of predicted values of all spirometric

parameters. All the spirometric parameters

showed the decline in the percent difference

(between predicted and actual value).

In group A (age 20-30 years) the FVC,

FEV1, and FEV1/FVC, showed decline which

did not reach statistically significance; but

FEF25-75% and PEFR had very highly

significant decline statistically. All the

parameters with exception of FEV1/FVC had a

statistically significant decline when compared

to their controls.

In group B (age 31-40 years) the FVC,

and FEV1/FVC, showed decline which was not

statistically significant. The FEV1, FEF25-75%

and PEFR had very highly significant decline

statistically and 11% subjects were found to

have the findings of restrictive lung disease

Table 2 Incidence of Common Respiratory Symptoms in Past Three Months

Symptoms in Past 3 Months % of Subjects

(n=210)

% of Controls

(n=430)

p value

Frequent episodes of sneezing 18 5 <.001**

Fever 12 3 <.05*

Muscular aches 25 2 <.001**

A general unwell feeling (malaise) 35 4 <.0001

Dry cough 28 7 <.001**

Cough with phlegm / expectoration 22 4 <.001**

Shortness of breath 17 3 <.001**

Incidence of sore throat 30 3 <.0001**

Loss of appetite 43 5 <.0001**

Lack of energy 35 4 <.0001**

Failure to gain weight 14 5 <.001**

Consulted the physician for respiratory Symptoms

at least twice in last three months. 55 3 <.0001

**

**- Highly Significant p<0.001,

*- Significant p<0.05



(FEV1/FVC ≥ 70% and FVC <80%predicted) 20-

21. Very highly significant decline in all the

parameters was noted when group A was

compared to group B. Increased incidence of

respiratory symptoms in Group A could have

influence in the decline of lung function tests.

DISCUSSION In the present study we conducted the

analysis of the contaminated dust in terms of

suspended particulate matter and microbes; the

effect of exposure to such mixed vegetable dust

in terms of prevalent symptoms and lung

functions FVC, FEV1, FEV1/FVC, FEF25-75%

and PEFR in exposed Indian group and

compared them to matched controls in the two

age groups decade apart.

The descriptive cross sectional, random

sample study was conducted right at the work

place including spirometry just before or within

one hour of start of work shift. Disease and

exposure were ascertained simultaneously. This

study design was chosen because it was simple

and rapid in execution to provide rapid answers.

But the disadvantages were inability to study

exact etiology because the time sequence

between exposure and outcome could not be

ascertained; the study faced a high respondent

bias and over-representation of diseases of long

duration due to self reported health information.

We had no access to actual medical records of

these subjects.

The results of our study show decline in

all spirometric parameters especially in air flows

as shown by statistically very highly significant

decline in FEF25-75% and PEFR in the

exposed group when compared with the

unexposed group. The decline was more and

statistically very highly significant in group B

(age 31-40 years) and remained so when we

compared the younger age group A with elder B,

with longer duration of exposure and may

indicate involvement of medium and large

airways. Our subjects were not obese as per

Body mass index (BMI) calculations considering

that obesity is a potential common cause of

spirometric restriction 22

.

In a study 23

to assess exposure to

various constituents of organic dust generated

during the processing of hemp and

microbiological analysis of air quality

demonstrated significant bacterial and fungal

contamination in the air, so much that individual

identification of species was not possible.

In Australia a cross sectional study 24

of

1232 adult participants concluded that

occupational exposures to biological dusts were

associated with an increased risk of COPD

which was higher in women. In another study 25

240 workers of two Ukrainian fodder production

plants have been examined for respiratory

symptoms, lung function and bronchial

reactivity. In this study a comparison between

animal feed workers and internal controls

revealed work-related symptoms and lung

function effects predominantly indicating a

clinical picture related to chronic bronchitis.

Lung function clearly decreased with increasing

duration of employment. Obstruction of small

bronchi and bronchial hyper responsiveness

were the early signs of respiratory troubles in

exposed workers and may indicate involvement

of medium and large airways and on correlation

suggest that changes are the result of

inflammation and subsequent repair.

Table 3 Spirometry Results (% of predicted value) in the Study group (mean ± SD)

Parameter

Group A

(20-30 years) Group B

(31-40 years)

Subjects

(n= 110)

Control

(n= 220)

Subjects Vs

Control

P value#

Subjects

(n= 100)

Control

(n=210)

Subjects Vs

Control

P value#

Group A Vs

Group B

P value#

FVC 91.36 ±6.29 102.16 ±10.15 .05* 80.30±12.47 99.40±12.81 .473‡ 0.38‡

FEV1 % 90.5±7.44 102.72±9.66 .001** 91±9.4 102.42±11.11 .001** 0.001**

FEV1/FVC 102.90±3.26 100.61±4.32 .06‡ 109.1±6.77 97.64±4.66 .001** 0.05*

FEF25-75% 75.61±9.32 110.09±22.45 .02* 66.28±9.05 87.7±20.34 .000** 0.000**

PEFR 71.45±11.67 95.16±8.99 .0000** 67.14±12.17 93.2±11.33 .000** 0.05*

#- Student’s t test, **- Highly Significant p<0.001, *- Significant p<0.05, ‡- Not Significant p>0.05



A 5 year follow up study on 218

workers exposed to organic dust from

composting plants 26

showed accelerated decline

in FVC% and is associated with adverse acute

and chronic respiratory health effects. Our

subjects were non-smokers but some were

exposed to it passively. The order of severity of

the small airway disease (respiratory bronchioles

and membranous bronchioles) in non smoking

non agricultural workers; non smoking

agricultural workers (as our study group);

smoking non agricultural workers; smoking

agricultural workers have been studied27-28

.

In our study we observed reductions in

the FVC and/or the FEV1.

Disproportionate

reductions in the FEV1 as compared to the FVC

(and therefore the FEV1 -to-FVC ratio) is the

hallmark of obstructive lung diseases. The lung

diseases includes but is not limited to asthma,

acute and chronic bronchitis, emphysema,

bronchiectasis, pneumonia, and bronchiolitis29

.

The increased incidence of respiratory

symptoms in the subjects makes it necessary to

evaluate them so as to exclude these diseases.

FEF 25–75% gives an indication of what

is happening in the lower airways. It is a more

sensitive parameter and not as reproducible as

the others. It is a useful serial measurement

because it will be affected before FEV, so can

act as an early warning sign of small airway

disease. Our subjects had a very highly

significant decline in this value indicating the

small airway problem with exposure to

vegetable dust. The mechanism responsible for

the reduction in airflow as shown by decline in

FEF25-75% and PEFR can be bronchial spasm,

airway inflammation, increased intraluminal

secretions, and/or reduction in parenchymal

support of the airways due to loss of lung elastic

recoil.

CONCLUSION The results of this study show that

exposure to vegetable dust would expose the

population to a wide variety of harmful microbes

resulting in a variety of increased respiratory

symptoms and decrease lung capacities and

airflows during the years. Although more

comprehensive, long-term prospective and

specific studies are necessary, yet we

recommend control of pollution by taking

appropriate measures to inhibit the growth of

microbes; a detailed study of other harmful

components in such dust like fertilizers,

pesticides and insecticides. These contaminants

may cause general irritant or specific allergic

reactions in respiratory ducts and even lung

tissue. We also recommend providing standard

and appropriate protective tools (mask) for

workers who are exposed to dusts; and, finally,

periodic assessment of pulmonary function by

spirometry for workers who are exposed to

organic dusts and assessment of other preventive

action.

CONFLICTS OF INTEREST

None declared

REFERENCES

1. Ragnar Rylander MD. The role of endotoxin for

reactions after exposure to cotton dust.

Environmental & Occupational Health, Journal

Home. 2007; 12(6 ): Abstract Article first

published online. Available from:

http://onlinelibrary.wiley.com/doi/10.1002/ajim.

4700120607/abstract

2. Ragnar Rylander. Organic dust and lung disease:

The role of inflammation. Ann Agric Environ

Med 1999; 1:7-10.

3. O'Neill ME and Thorne PS Bio monitoring for

assessment of organic dust-induced lung

inflammation. Eur Respir J 2006; 27:1096-

1101.

4. Dutkiewicz J, Górny RL. Biologic factors

hazardous to health: classification and criteria

of exposure assessment. Med Pr. 2002;

53(1):29-39. [ in Polish]

5. Zenz C. Textbook of Occupational Medicine. In

Dickerson OB, Horvath EP 3rd

edition.Chicago:

Mosby; 1994.

6. Rom WN. Textbook of Environmental and

Occupational Medicine. 3rd ed. Philadelphia:

Lippincott-Raven; 1998.

7. Krewski D, Jerret M et al. Extended follow up

and spatial analysis of the American Cancer

Society study linking particulate air pollution

and mortality. Resp Rep Health Eff Inst. 2009;

140:5-11.

8. WHO strategy for prevention and control of

chronic respiratory diseases. Geneva: World

Health Organization; 2002.Available from

http://www.who. int / respiratory / publications/

http://onlinelibrary.wiley.com/doi/10.1002/ajim.v12:6/issuetoc

http://www.ersj.org.uk/search?author1=M.+E.+O%27Neill&sortspec=date&submit=Submit



who_mnc_cra_02.1.pdf. Accessed May 10,

2010.

9. Kakde Ub, Kakde HU. Incidence of post

harvest disease and airborne fungal spores in a

vegetable market. Acta Bot Croat. 2012; 71(1):

147-157.

10. Indoor Air Pollution (IAP) updates India –

Chest Research Foundations studies

respiratory disease. 2010January 25,

envhealth@usaid IAP news and research alerts.

Environmental Health at USAID.

11. Andersen A A. New sampler for the collection,

sizing, and enumeration of viable airborne

particles. J. Bacteriol. 1958; 76:471-484.

12. Anderrsen A A. A sampler for respiratory

health hazards assessment. Am.Ind Hyg. Assoc.

J 1966; 27: 260 - 265.

13. Krieg N R : Enrichment & Isolation. In:

Gerhasdt P, Murray RGE, Costilow RN, .

Nester EW, Wood WA, Krieg NR and Phillips

GB. (Eds). Manual of Methods for General.

Bacteriology, Am. Soc. Microbiol. Washington

DC. Lacy J and Dutkiewicz J.1981.

14. Douwes J, Thorne P, Pearce N, Heederik D. Bio

aerosol health effects and exposure assessment:

progress and prospects. Ann Occup Hyg. 2003;

47(3):187-200.

15. .Bellia V, Pistelli F, Giannini D, Scichilone N,

Catalano F, Spatafora M, et al. Questionnaires,

spirometry and PEF monitoring in

epidemiological studies on elderly respiratory

patients. Eur Respir J Suppl 2003; 40:21S-27S.

16. Boskabady MH, Fasihfar M, Maemoori G A.

Correlation between symptom score, wheeze,

reversibility of pulmonary function tests and

treatment response in asthma. Iran J Allergy

Asthma Immunol 2003; 2(2):61-67.

17. American Thoracic Society. Standardization of

spirometry, 1994 update. Am J Respir Crit Care

Med 1995; 152(3):1107-1136.

18. Daniel Soper.com [Internet] Statistics

Calculator version 2.0 Available from :

http://www.danielsoper.com/statcalc/calc08.asp

x

19. State of Environment Report: Maharashtra

Indira Gandhi Institute of Development

Research Mumbai-400065 (India) Maharashtra

Pollution Control Board sponsored by Ministry

of Environment and Forests, Govt. of India.

(FINAL DRAFT) Page 100-101

20. Knudson RJ, Lebowitz MD, Holberg CJ et al.

Changes in the normal maximal Expiratory

flow-volume curve with growth and aging. Am

Rev Respir Dis 1983;127:725 e 34.

21. American Thoracic Society. Respiratory health

hazards in agriculture. Am J Respir Crit Care

Med 1998;158:S1–S76.

22. Ray CS, Sue DY and Bray G. Effects of obesity

on respiratory function. Am Rev Respir Dis

1983; 128:501- 6.

23. David Fishwick, Lisa J. Allan, Anthony Wright

and Andrew D. Curran. Assessment of

Exposure to Organic Dust in a hemp Processing

Plant. The Annals of Occupational Hygiene

2001; 45 (7):577-583.

24. Matheson MC, Benke G, Raven J, Sim MR,

Kromhout H, Vermeulen R, John DP, Walters

EH, Abramson MJ. Biological dust exposure in

the workplace is a risk factor for chronic

obstructive pulmonary disease. Thorax 2005;

60: 645-651.

25. Kuchuk AA, Basanets A, Louhelainen K.

Broncho pulmonary pathology in workers

exposed to organic fodder dust. Ann Agric

Environ Med. 2000; 7(1):17-23.

26. Bunger J,Schappler-Scheele b, Hilgers r, Hallier

E. A 5 year follow up study on respiratory

disorders and lung function in workers exposed

to organic dust from composting plants. Int

Arch Occup Environ Health. 2007; 80: 306-

312.

27. Rylander R. Endotoxin in the environment-

exposure and effects. J Endotoxin Res 2002;

8:241–252.

28. Marc B. Schenker, Kent E. Pinkerton, Diane

Mitchell, Val Vallyathan, Brenda Elvine-Kreis,

Pneumoconiosis from Agricultural Dust

Exposure among Young California Farm

workers, Environmental Health Perspectives.

2009; 117: 998-994.

29. Thomas R.Gildea, Kevin McCarthy. Pulmonary

Function Testing. Cleveland Clinic

Publications, Monthly CME e news paper,

available from

http://www.clevelandclinicmeded.com/medical

pubs/diseasemanagement/pulmonary/pulmonar

y-function-testing/

For More Information Log on to

www.ijhrs.com

Documents

Kurhade G, Kurhade A, Phatak MS, Farid Y. A Cross Sectional Study of Respiratory Symptoms and Spirometry in Adults Exposed to Bio aerosol in Vegetable Market in India. Int J Health