Lung cancer mortality among male nuclear workers of the Mayak facilities in the former Soviet Union

An analysis of lung cancer mortality in a cohort of 1,669 Mayak workers who started their employment An the plutonium and reprocessing plants between 1948 and 1958 has been carried out in terms of a relative risk model. Parti cular emphasis has been given to a discrimination of the effects of externa l gamma-ray exposure and internal alpha-particle exposure due to incorporat ed plutonium. This study has also used the information from a cohort of 2,1 72 Mayak reactor workers who were exposed only to external gamma rays. The baseline lung cancer mortality rate has not been taken from national statis tics but has been derived from the cohort itself. For both alpha particles and gamma rays, the results of the analysis are consistent with linear dose dependences. The estimated excess relative risk per unit organ dose equiva lent in the lung due to the plutonium a particles at age 60 equals, accordi ng to the present study, 0.6/Sv, with a radiation weighting factor of 20 fo r cu particles. The 95% confidence range is 0.39/Sv to 1.0/Sv, For the gamm a-ray component, the present analysis suggests an excess relative risk for lung cancer mortality at age 60 of 0.20/Sv, with, however, a large 95% conf idence range of-0.04/Sv to 0.69/Sv, (C) 2000 by Radiation Research Society.