Risk assessment of lung cancer and asbestosis in workers exposed to asbestos fibers in brake shoe factory in Iran.

Chrysotile asbestos fiber, imported from Russia, is used mainly for manufacturing purposes in Iran and related risks in the form of asbestosis and cancer were studied. Occupational exposure of all male workers (61 persons) to asbestos in a brake shoe factory was monitored. Cumulative exposures were determined through multiplication of typical exposure and work history. Risk assessment of exposed workers was estimated by risk criteria recommended by the American Environmental Protection Agency. Measurement of lung function parameters such as forced expiratory volume in one second (FEV(1)), forced volume capacity (FVC) and FEV(1)/FVC of exposed workers were obtained. Unadjusted correlation and adjusted correlation analysis for support of the association between cumulative exposure (fiber/ml-yr) and lung function parameters were used. Exposure of majority of exposed group was far greater than the occupational exposure limits (0.1 fiber/ml) in the range of 0.06-8.06 fiber/ml. Cumulative exposures in the range of 0.02 to 110.77 fiber/ml-yr were obtained. According to the risk criteria stated by ATSDR, risk assessment of workers in term of fibrotic changes was predicted for at least 24.6 percent of the exposed subjects. Again, according to the lung cancer risk criteria stated by EPA, 59 percent of workers will have excess risk. Negative correlation between lung function parameters (FEV(1), FEV(1)/FVC) and cumulative exposures adjusted for age and BMI were significant (p<0.05).