| This follow-up study of uranium processing workers at the Fernald Feed Materials Production Center examines the relationship between radiation exposure and cancer and noncancer mortality among 6403 workers employed for at least 30 days between 1951 and 1985. |
| Methods: We estimated cumulative, individual, annualized doses to 15 organs/tissues from external, internal, and radon exposures. Vital status and cause of death were ascertained through 2017. The analysis employed standardized mortality ratios (SMRs), Cox proportional hazards, and Poisson regression models. Competing risks analysis was conducted for cardiovascular disease (CVD) mortality risk given several assumptions about risk independent of competing outcomes. Emphysema was examined to assess the potential for confounding by smoking. |
| Results: Vital status was confirmed for 98.1% of workers, with 65.1% deceased. All-cause mortality was less than expected in salaried but not hourly workers when compared with the U.S. population. A statistically significant dose-response was observed between external (but not total or internal) lung dose and lung cancer mortality [hazard ratio (HR) at 100 mGy adjusted for internal dose=1.45; 95%CI=1.05, 2.01). Significantly increased HRs at 100 mGy dose to heart were observed for CVD (1.27; 95%CI=1.07, 1.50) and ischemic heart disease (1.30; 95%CI=1.07, 1.58). CVD risk remained elevated regardless of competing risks assumptions. Both external and internal radiation were associated with emphysema. |
| Conclusions: Lung cancer was associated with external dose, though positive dose-responses for emphysema imply residual confounding by smoking. Novel use of competing risks analysis for CVD demonstrates leveraging retrospective data for future risk prediction. |