Comparative analysis of radiogenic risk of ischemic heart disease and cerebrovascular diseases in the cohort of workers chronically exposed to radiation

Circulatory diseases are the leading cause of death all around the world. Even a small increase in radiogenic risk would lead to a significant increase in incident cases and deaths as the number of individuals exposed to radiation for different purposes increases constantly. The aim of the study was a comparative analysis of radiogenic risk of incidence and mortality from ischemic heart disease and cerebrovascular diseases in the cohort of Mayak Production Association workers based on several dosimetry systems. The first analysis of studied incident cases and death causes was performed using dosimetry system “Doses-2005” which included data on occupational histories as well as external and internal radiation exposure doses for workers employed at one of the main facilities during 1948–1972. The subsequent dosimetry systems, “MWDS-2008” and “MWDS-2013”, additionally included data for workers employed in the later years (1973–1982). The necessity to improve the external dose estimates was conditioned by a number of factors, i.e. using different types of dosimeters during all monitoring period, lack of accounting for individual radiation exposure specificities for separate workers etc.; whereas discrepancies between plutonium activities in some organs/tissues estimated by the systems and the ones measured in autopsy samples made for improvements in internal dosimetry system. Conclusion: The excess relative risk estimate for ischemic heart disease incidence and mortality was the most significantly affected by the improvements in dosimetry system for the internal exposure due to incorporated plutonium.