Exposure to nitrosamines, carbon black, asbestos, and talc and mortality from stomach, lung, and laryngeal cancer in a cohort of rubber workers

There is sufficient evidence for an excess occurrence of stomach and lung c ancer among rubber workers. However, evidence for causal associations with specific exposures is still limited. A cohort of 8,933 male German rubber w orkers was followed for mortality from January 1, 1981 through December 31, 1991. Work histories were reconstructed using routinely documented cost ce nter codes. For each cost center code, calendar time- and plant-specific le vels of exposure to nitrosamines, asbestos, talc (low, medium (m), and high (h)), and carbon black (two levels) were estimated by industrial hygienist s. Rate ratios (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards models, with the lowest exposure level used as th e reference category. Exposure was lagged 10 years to account for latency E xposure-response relations between exposure to asbestos and lung cancer mor tality (RRm = 1.3, 95% CI: 0.9, 1.9; RRh = 2.0, 95% CI: 0.9, 4.1) and betwe en exposure to dust (talc and asbestos combined) and stomach cancer mortali ty (RRm = 1.8, 95% CI: 0.9, 3.8; RRh = 2.7, 95% CI: 1.0, 7.1) were observed . Exposure to nitrosamines was not associated with mortality from stomach o r lung cancer. These results suggest that the increased mortality from lung and stomach cancer among rubber workers is associated with exposure to asb estos and dust, respectively.