Occupational exposure and mortality among workers at three titanium dioxide plants.

A cohort of 3,607 workers employed in three DuPont titanium dioxide production facilities was followed from 1935 through 2006. Combined and plant-specific cohort mortality was compared with the overall US population and other DuPont employees. The relationships between selected causes of death and annual cumulative exposures to titanium dioxide and chloride were investigated using Poisson regression methods to examine trends with increasing exposure. Among the 833 deaths, no causes of deaths were statistically significantly elevated either overall or plant-specific when compared to the US population. Compared to DuPont workers, statistically significantly elevated SMRs for all causes, all cancers, and lung cancers were found driven by the workers at the oldest plant. Comparing increasing exposure groups to the lowest group, disease risk did not increase with exposure. There was no indication of a positive association between occupational exposure and death from all causes, all cancers, lung cancers, non-malignant respiratory disease, or all heart disease.