LEVELS AND RELATIVE RISKS OF MORTALITY OF CHORNOBYL CLEAN-UP WORKERS IN 1986-1987 YEARS FROM MAIN NON-NEOPLASTIC...

The emergency destruction of the 4th reactor of the Chornobyl nuclear power plant necessitated large-scale emergency work, which involved large contingents of specialists. Analysis the mortality of Chornobyl clean-up workers isan important and relevant basis for planning medical protection measures in conditions of a potential threat ofemergency and other radiation situations.The objective of this work is to determine the levels and relative risks of mortality of Chornobyl clean-up workers in1986-1987 years from major non-tumor diseases depending on the received dose of radiation exposure, taking intoaccount age and time after the accident (period of epidemiological studies 1988-2021).

The cohort of Chornobyl clean-up workers in 1986-1987 years with a known dose of external γ-irradiation of the whole body, totaling 64,490 male, was divided by age at the date of the accident at theChornobyl nuclear power plant and dose of external γ-irradiation of the whole body. Epidemiological analysis of mortality from non-tumor diseases was conducted for the entire post-accident period and in dynamics over five-yearmonitoring periods.

The highest mortality rate, regardless of age, on the date of the Chornobyl disaster, were from diseases of thecirculatory system, of the digestive and respiratory systems. For Chornobyl clean-up workers 18-39 years on the dateof the accident, relative risks of mortality from non-tumor diseases over the entire observation period were significantly higher in all dose subgroups (from 0.05 Gy to 0.7 Gy) compared to the dose subgroup < 0.05 Gy. In the period1993-1997 (6-10 years after the Chornobyl accident), significantly higher relative risks of mortality from diseases ofthe circulatory system (pulmonary heart and pulmonary circulatory disorders, cardiomyopathy, myocardial infarction)were found; in 26-30 years - from cerebrovascular diseases, including cerebral infarction. The indicated reliabledose-dependent relative risks are characteristic of all dose subgroups relative to the subgroup with a dose < 0.05 Gy.

The overall mortality of Chornobyl clean-up workers from non-tumor diseases tends to increase. Theresults of the risk analysis of dose dependent mortality in the Chornobyl clean-up workers cohort showed a highersensitivity to ionizing radiation of persons of the younger age group (18-39 years old at the date of the accident).The most dangerous period of relative dose-dependent risk of death of Chornobyl clean-up workers due to non-tumordiseases was established - 6-10 years after radiation exposure for all dose subgroups (from 0.05 Gy to 0.7 Gy) relative to the subgroup with a radiation dose < 0.05 Gy.