Astract
The objective was to study the effect of occupational dust exposure on respiratory disease in stone crushing workers. A set of 125 workers from two different occupations were studied regarding respiratory abnormalities. Out of the sample, 50 are stone crushing workers (exposed) and 75 are ornamental industry workers (non-exposed). Persons who are non-exposed are more likely to have normal chest expansion and normal PEFR than exposed persons are. That is chest expansion and PEFR are more likely to be negative indicators of respiratory disease. The percentages of normal indicators for workers who are not exposed to dust are high; than the percentages of abnormal indicators for exposed workers.

Introduction

Respiratory illnesses in workers of stone crushing industries is a significant problem all over the world. One million people are dying annually in the world. 1.7 million are affected in India alone. Billions of rupees are spent on their treatment annually.

We took this study because hundreds of stone crushers are spread around our city, Guntur, employing thousands of workers. They are frequently seen in our hospital in pulmonology unit. They are reportedly occupying around 60% of pulmonology ward beds. To get the actual picture we did this field study.

By our study, we established that a number of stone crushing workers are suffering from respiratory diseases than those of ornamental workers (non- exposed).

Material and Methods

Type of study : Cross-sectional.
Study design : Field based.
Period of study : From September 2004 to January 2005, a total of five months.
Sample Size : A set of 125 workers from two different occupations were studied regarding respiratory abnormalities. Out of the sample 50 are stone crushing workers (exposed) and 75 are ornamental industry workers (non-exposed).
Apparatus : Tailor tape – chest expansion, Wrights peak expiratory flow meter – P.E.F.R.

Method

Study population was selected on the following criteria :-

1. The age group was between 35-50 years
2. Minimum period of occupation in their respective field was 2 years
3. Low socio economic status
4. Body mass index of 23-26 are taken
5. Only non-smokers are taken into consideration
6. Same height and sex calculated for differences.

The minimum period of occupation in their respective fields was taken two years, so that study groups are adequately exposed to their working environment.1 Care is taken not to include workers who first worked in stone crushing industry and changed their occupation to ornamental industry.

Low socio economic status is taken to normalize their education and other protective measures, and also low socio economic status is an independent risk factor for chronic respiratory illnesses.²

As PEFR changes with height and sex, they are adjusted for such differences. PEFR (L/min) = [Height (cm) - 80] x 5.^13,14

Quantitative measurements like PEFR and chest expansions are noted using Wright’s peak expiratory flow meter and measuring tape respectively.

All the readings were taken in evening after their work is completed.

PEFR of 400 to 500 litres/minute was taken as normal for males and 300-400 litres/ minute was taken as normal for females.³

The chest expansion of 5 cm is taken as normal workers with body mass index of 23-26 are only taken because chest expansion and PEFR differ with obesity and leanness.⁴

Results

Persons who are non-exposed are more likely to have normal chest expansion and normal PEFR than exposed persons are. That is chest expansion and PEFR are more likely to be negative indicators of respiratory disease. The percentages of normal indicators for Workers who are not exposed to dust are high; than the percentages of abnormal indicators for exposed workers.

Discussion

Measurement of respiratory disease by peak expiratory flow meter and chest expansion are very good instrument in clinical practice.12 This is a simple method of measuring airway disease and it will detect moderate or severe disease. The simplicity of the method is its main advantage. It is measured using a standard Wright Peak Flow Meter or mini Wright Meter and Measuring tape.

From the tables it can be noted that, Normal chest expansion is 37% in exposed compared to 55% in non-exposed, that is non-exposed persons are more likely to have normal chest expansion than exposed persons (Table 2, Fig. 2).

Like wise, Normal PEFR is more likely to be present in non-exposed (53%) than inexposed (35%) (Table 1, Fig. 1).^1,5

To conclude, persons who are non-exposed are more likely to have normal chest expansion and normal PEFR than exposed persons.^8-11

References

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Fig.1	Fig.2

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13. Normal values are related to the patient’s height. http://www.med.monash.edu.au/paediatrics/resources/pefr.html.

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