Lung Cancer Risks from Plutonium: An Updated Analysis of Data from the Mayak Worker Cohort

Workers at the Mayak nuclear facility in the Russian Federation offer a unique opportunity to evaluate health risks from exposure to inhaled plutonium. Risks of mortality from lung cancer, the most serious carcinogenic effect of plutonium, were evaluated in 14,621 Mayak workers who were hired in the period from 1948–1982, followed for at least 5 years, and either monitored for plutonium or never worked with plutonium. Over the follow-up period from 1953–2008, there were 486 deaths from lung cancer, 446 of them in men. In analyses that were adjusted for external radiation dose and smoking, the plutonium excess relative risk (ERR) per Gy declined with attained age and was higher for females than for males. The ERR per Gy for males at age 60 was 7.4 (95% CI: 5.0–11) while that for females was 24 (95% CI: 11–56). When analyses were restricted to plutonium doses <0.2 Gy, the ERR per Gy for males at age 60 was similar: 7.0 (95% CI: 2.5–13). Of the 486 lung cancer deaths, 105 (22%) were attributed to plutonium e...