A reevaluation of selected mortality risks in the updated NCI/NIOSH acrylonitrile cohort study.

Objectives: The study aimed to determine whether the National Cancer Institute's (NCI) recent suggestion of associations between acrylonitrile (AN) exposure and mortality in lung and bladder cancer and pneumonitis is robust to alternative methods of data analysis. Materials and methods: We used the Richardson method to indirectly adjust risk ratios (RRs) in relation to AN exposure for potential confounding by smoking and asbestos. We repeated key analyses omitting workers from Plant 4 to account for possible local, historical shipyard-related asbestos exposures. Results: The adjustment of lung cancer RRs for confounding by both smoking and asbestos and omitting Plant 4 workers yielded mostly decreased RRs and much less evidence of a positive association with cumulative AN exposure. Conclusion: Overall, our reanalysis provided little evidence to support NCI's suggestion of associations between AN exposure and mortality in lung and bladder cancer and pneumonitis.

Mortality Patterns Among Industrial Workers Exposed to Chloroprene and Other Substances: Extended Follow-Up.

OBJECTIVES: To update the U.S. portion of an historical cohort mortality study of workers with potential exposure to chloroprene (CD) and vinyl chloride (VC) with focus on lung and liver cancer. METHODS: Subjects were 6864 workers from two sites with vital status determined through 2017 for 99% of subjects and cause of death for 97.2% of deaths. Historical exposures to CD and VC were estimated quantitatively. We performed external and internal mortality comparisons. RESULTS: External comparisons revealed mostly deficits in deaths; internal comparisons revealed no consistent evidence of exposure-response relationships with CD or VC. CONCLUSIONS: Our update continues to support the conclusion that the risk of death from lung or liver cancer is unrelated to exposure to CD or VC at levels experienced by workers in the two U.S. sites.