Mortality from cancer and other causes in the balangero cohort of chrysotile asbestos miners

OBJECTIVES: To provide further information on mortality from cancer and other causes among chrysotile asbestos miners several years after stopping exposure, we updated the analyses from the cohort of Balangero mine workers with follow-up to the end of 2003. METHODS: The cohort included 1056 males, for a total of 34,432 man-years of observation. We obtained employment data from personnel records at the factory, and ascertained vital status and causes of death through population registers and death certificates from municipal registration offices. We computed expected numbers of death and standardized mortality ratios (SMR) for relevant causes using the province of Turin and national death rates, for each 5-year calendar period and age group. RESULTS: We found a significant excess mortality from pleural cancer only (4 deaths, SMR=4.67) and pleural and peritoneal cancers combined (5 deaths, SMR=3.16). All pleural and peritoneal cancer deaths occurred 30 or more years after first exposure. The SMRs were 1.27 for lung cancer (45 deaths), 1.82 for laryngeal cancer (8 deaths) and 1.12 for all cancers (142 deaths). Cumulative dust exposure and various time factors considered did not show a clear pattern of risk with mortality from lung cancer. There were 57 deaths from cirrhosis (SMR=2.94) and 54 from accidents and violence (SMR=1.88). Overall, we observed a total of 590 deaths as compared to 412.9 expected (SMR=1.43). CONCLUSIONS: This updated analysis, with almost 60% of workers of the cohort who had died, confirmed the excess mortality from pleural and peritoneal cancers and from several alcohol-related causes.