Impact of radiation on the atherosclerosis incidence in men participated in mitigation of the consequences of the accident at the Chernobyl NPP

The statistical relationship between radiation dose to the cohort of workers (liquidators), participated in mitigation of effects of the Chernobyl accident are considered in the paper. The follow-up data collected from 1992 to 2021 and accumulated in the National Radiation and Epidemiological Register (NRER) were used for analysis. The cohort of liquidators consisted of 67,304 males. The average radiation dose in the cohort was 0.13 Gy, and the average age at radiation exposure was 34 years. During the follow-up period 10,790 atherosclerosis cases (ICD-10, code 170) were detected for the first time. To identify statistical relationship between radiation dose and atherosclerosis incidence, general “data mining” approaches were used, that do not use hypotheses about the probabilistic laws of random variable distributions, that determine the relationship between radiation dose and atherosclerosis incidence. A group of liquidators with accumulated during the period of work individual radiation doses below 0.15 Gy was selected as the reference group. The maximum radiation dose in the studied cohort was 1.4 Gy. Statistically significant relationship between radiation doses and atherosclerosis incidence (ICD-10, code 170) were found: relative radiation risk RR=1.05 at 95% lower confidence bound 1.027. The relative risks (RR) for individual diagnoses are: RR=1.22 (95% CI lower bound - 1.20) for ICD-10 - I70.0 (aortic atherosclerosis); RR=1.03 (95% CI lower bound - 1.01); for ICD-10 - I70.2 (limb artery atherosclerosis); RR=1.06 (95% CI lower bound - 1.04) for ICD-10 - I70.9 (generalized and unspecified atherosclerosis). The RR increases with the age at diagnosis. The results obtained can be the basis for the design of radiation-epidemiological studies for the detailed quantitative study of the detected dose-effect relationships.