Hypertension Incidence Risk in a Cohort of Russian Workers Exposed to Radiation at the Mayak Production Association Over Prolonged Periods

The study was aimed to assess hypertension incidence risk in a cohort of workers occupationally exposed to ionizing radiation. The cohort included workers of Russian Mayak nuclear enterprise who were employed in 1948 to 1982 and followed up until December 31, 2013 (22377 workers). All workers were occupationally exposed to external -rays and some (76.03%) also to -particles from internally deposited plutonium. Mean cumulative absorbed liver doses from external -rays (mean +/- SD) were 0.45 +/- 0.65 Gy in male and 0.37 +/- 0.56 Gy in female, whereas doses from internal -particles were 0.23 +/- 0.65 and 0.44 +/- 1.93 Gy in males and females, respectively. An excess relative risk per unit dose was calculated based on Poisson regression analysis and was described as linear and nonlinear trends with radiation dose including adjustments for nonradiation factors via stratifications. As of the end of the follow-up period, 8425 hypertension cases (38% of workers) were verified in the cohort (5745 cases in males [36%] and 2680 cases in females [49%]). Hypertension incidence was found to be significantly linearly associated with cumulative liver absorbed dose from external -rays: excess relative risk/Gy=0.14 (95% CI, 0.09-0.20). No significant association of hypertension incidence with cumulative liver absorbed dose from internal -particles was found: excess relative risk/Gy=-0.01 (95% CI, non-available-0.05). Hypertension incidence risk in the study cohort was higher than that in the Japanese cohort of atomic bomb survivors (AHS [Adult Health Study]) but lower than a corresponding estimate for Chernobyl clean-up workers.