Chemical exposures of rocket-engine test-stand personnel and cancer mortality in a cohort of aerospace workers.

We conducted a retrospective cohort study of 6107 aerospace workers to examine whether exposure to chemicals--primarily hydrazine fuels--during rocket-engine fueling and testing affects cancer mortality. When conditional logistic regression analysis was applied and adjusted for confounding variables, the estimated rate ratio for lung cancer mortality, comparing exposed to unexposed workers from the same facility, ranged from 1.68 (95% confidence interval, 1.12 to 2.52) to 2.10 (95% confidence interval, 1.36 to 3.25), depending on job-duration threshold (6 or 24 months) and lag (0 to 15 years). Similar results were obtained for hemato- and lymphopoietic cancer and for bladder and kidney cancer mortality, but estimates for these cancers were imprecise. We concluded that occupational exposure to hydrazine or other chemicals associated with rocket-engine testing jobs increased the risk of dying from lung cancer, and possibly other cancers, in this population of aerospace workers; however, our results need to be replicated in other populations.