Quantitative exposure-response for silica dust and lung cancer in Vermont granite workers

Abstract

Background: Excess lung cancer mortality among the exposed Vermont granite workers has been reported. These studies were based on job and tenure surrogates, with the potential for misclassification and inability to evaluate quantitative exposure-response.

Methods: Industrial hygiene data collected from 1924 to 1977 was analyzed in conjunction with mortality data to examine quantitative exposure-response for silica, lung cancer, and other lung diseases. A person-years analysis was undertaken by cumulative exposure group, including lagged and unlagged tabulations. Poisson models were fitted to untransformed and log transformed exposure.

Results: The results indicated a clear relationship of lung cancer, tuberculosis, pneumoconiosis, non-malignant lung disease, and kidney cancer with cumulative exposure. An exposure to 0.05 mg/m(3) from age 20 to 64 was associated with a lifetime excess risk of lung cancer for white males of 27/1,000.

Conclusions: The results of this study of workers exposed almost exclusively to silica and no other major occupational confounding exposures indicate a clear exposure-response for lung cancer.