Estimates of lifetime risk of lung cancer death under different scenarios of 239Pu inhalation

The annual value of lifetime excess risk of lung cancer mortality and lifetime excess risk over a period starting at age of first exposure to 239Pu - 20, 30, 40, 50 years - and ending at age 70 years were assessed with the use of the previously developed model for estimating excess relative risk, national statistical data on mortality from all causes and lung cancer, as well as estimates of lung cancer death risk in the cohort of the Mayak Production Association workers. Lifetime excess lung cancer mortality risk to the age of 70 years associated with annual occupational inhalation of readily transportable 239Pu compounds in the amount of the maximum annual permissible intake over the period 20-70 years of age is 0.0008, and the risk from intake of poorly transportable 239Pu compounds is 0.084. Results of study demonstrate the following: the value of total 50-year acceptable risk associated with annual occupational inhalation of poorly transportable 239Pu compounds in the amount of the maximal permissible intake limit exceeds the limit. The annual value of the lifetime excess risk of lung cancer mortality over a period starting at age of first exposure to 239Pu - 20, 30 and 40 years - and ending at age 45, 50 and 60 years exceeds the established annual limit of acceptable risk - 0.001. The presented data point to the necessity of updating existing radiation safety standards, which have respect to inhalation intake of 239Pu.