Assessment of the relationship between lifetime rates and incorporation of plutonium-235 in atomic production workers

Introduction. The objective of the study was the quantitative assessment of the effect of internal exposure to the lifetime in Mayak PA workers based on analyzing the dependence of certain lifetime rates on the incorporation of plutonium-239.

Material and methods. There was investigated a cohort of deceased Mayak PA workers employed in 1948-1958 with known Pu-239 body burden comprising 2343 individuals, including 1739 males and 604 females. Using regression analysis we have assessed the dependence of general lifetime and lifetime after the start of work as well as of proportion of individuals who did not survive until standard age in general and after a start of work from incorporated Pu-239 separately for workers of different age. Statistical values were defined using STATISTICA software.

Results. It was stated that for 1 kBq of incorporated Pu-239: a general lifetime in males decreased by 0.32 years and after a start of work – by 0.41 years; in females – by 0.22 and 0.28 years respectively. For 1 kBq of incorporated Pu-239 proportion of males who did not survive until 65 years of general lifetime and proportion of males who did not survive 40 years after a start of work increased by 1.33 and 1.87% respectively; in females for 70 and 45 years – by 0.90 and 1.14% respectively.

Conclusion. Thus, the workers’ dependence of lifetime after a start of work on incorporated Pu-239 was higher than of a general lifetime. A proportion of workers who did not survive until the standard age after the start of work was higher than the proportion of workers who did not survive until a general standard age. Dependence of decrease of lifetime rates under the study from incorporated Pu-239 in males was more significant than in females.