Exposure to asbestos causes asbestosis, lung cancer and mesothelioma of pleura and peritoneum. In India, the total use of asbestos is 1.25 lakh tonnes, out of which more than 1.0 lakh tonnes is being imported. Significant occupational exposure to asbestos occurs mainly in asbestos cement factories, asbestos textile industry and asbestos mining and milling. NIOH has carried out studies in all these industries and generated baseline data. Following is the summary of these studies..
Asbestos Cement Industry
There are 18 asbestos cement factories located in different parts of the country. NIOH carried out environmental epidemiological studies in four asbestos cement factories located in Ahmedabad, Hyderabad, Coimbatore and Mumbai. The prevalence of asbestosis in these factories varied from 3% to 5%. The levels of asbestos fibres were found to be higher than the permissible levels of 2fibres/ml in two of the factories.
Asbestos Textile Industry
Making of asbestos yarn and ropes is done mostly in the unorganised sector of industries with very poor safety measures. The average levels of air borne asbestos fibres varied from 216 to 418 fibres/ ml. The permissible level is 2 fibres/ml. The prevalence of asbestosis was 9%. This relatively low prevalence of asbestosis despite high environmental levels was attributed to high labour turn over. Cases of asbestosis were observed in workers having less than 10 years exposure in contrast to the reported average duration of over 20 years.
Asbestos Mining and Milling
In India, the mining and milling of asbestos is done in Cuddapah (Andhra Pradesh) and Devgarh (Rajasthan). Environmental and epidemiological studies in mining and milling units were carried out in both the places. In asbestos mines at both locations, the air borne fibre levels were within permissible limits. The average fibre levels in milling units varied from 45 fibres/ml to 244 fibres/ml of air. The overall prevalence of asbestosis in mining and millingnits was 3% and 21% respectively