Occupational exposure to asbestos and man-made vitreous fibers, and risk of lung cancer: evidence from two case-control studies in Montreal, Canada.

Abstract : OBJECTIVE: To examine the effects of occupational asbestos and man-made vitreous fibers (MMVF) on the risk of lung cancer in two population-based case-control studies entailing exposure at lower levels than in historic cohort studies. METHODOLOGY: Study I (1979 to 1986) comprised 857 cases and 1066 population and cancer controls. Study II (1996 to 2001) comprised 858 cases and 1295 population controls. A detailed job history was obtained to evaluate lifetime occupational exposure to 294 agents, including asbestos and MMVF. RESULTS: We found increased risks for substantial exposure to asbestos (odds ratio = 1.78; 95% confidence interval: 0.94 to 3.36). The corresponding odds ratio for substantial exposure to MMVF was 1.10 (95% confidence interval: 0.37 to 3.22). DISCUSSION: Low and moderate levels of exposure to asbestos, as encountered in this population, were associated with some excess risk of lung cancer. Results for MMVF were inconclusive.