Mortality Among Hardmetal Production Workers: US Cohort and Nested Case-Control Studies.

Objectives: To evaluate total and cause-specific mortality among hardmetal production workers with emphasis on lung cancer. Methods: Subjects were 7304 workers ever employed in one of eight US plants from 1952 to 2008. Vital status through 2012 was determined for 97% of subjects and cause of death for 98.3% of 1087 deaths. We computed standardized mortality ratios (SMRs) and evaluated exposure-response via relative risk regression analysis. Results: We observed overall deficits in deaths for total mortality, all cancers, and lung cancer and found no evidence of any exposure-response relationships for lung cancer. Conclusions: We found no evidence that exposure to tungsten, cobalt, or nickel, at levels experienced by the workers examined, increases lung cancer mortality risks. We also found no evidence that work in the US hardmetal industry increases mortality risks from any other causes of death.