Purpose: A comparative analysis of the health of the liquidators of the consequences of the Chernobyl accident, employees of enterprises and enterprises of the nuclear industry, and residents of the Moscow region. Material and methods: The information bases of the Industrial Register of Persons Exposed to Radiation from the Chernobyl Accident and the Register of the Liquidators of the Consequences of the Chernobyl NPP Residents of the Moscow Region were used in the work. The development of the material was carried out according to the total morbidity and mortality rates of men + women in 2017 by disease classes (ICD-10). Statistical processing of the material was carried out in the Excel system; morbidity, mortality, their error, indicator structure (%), ratio indicator and reliability of the difference in indicators were calculated (p = 0.05 %). Results: The results of the study showed that the incidence of some diseases is higher among the liquidators of the consequences of the Chernobyl accident – residents of the Moscow region: incidence of diseases of the skin and subcutaneous tissue (ratio 2.0), urogenital system (ratio 1.7). There was a higher mortality from diseases of the digestive system among the liquidators of the consequences of the Chernobyl accident – residents of the Moscow region (ratio 1.8). Conclusion: The difference in the health indicators of the studied cohorts can be explained by the difference in their age structure and the difference in dispensary observation. The need for further observation of this cohort of individuals to increase the power of the study is shown.

Purpose: To assess the excess relative risk in terms of 1 Sv on the basis of materials on the incidence of malignant neoplasms of workers in the nuclear industry – liquidators of the Chernobyl accident, as well as part of workers who worked or continue to work with sources of ionizing radiation. Material and methods: The data base of the Industry Register of persons exposed to radiation as a result of the Chernobyl accident (ORF) was used in the work. Methods of cohort analysis of the accumulated disease incidence were used, based on Poisson regression and Cox regression. Estimates of the ERR at 1 Sv were calculated using both the traditional scheme using the AMFIT module and the modified formula proposed by Paretzke. Results: It is shown that in some cases, the risk estimates obtained by the modified formula are more realistic, in other cases both estimates have similar values. Conclusion: Analysis of the incidence of solid neoplasms in the liquidator cohort showed: 1. At the dose range < 200 mSv, point estimates of relative risk indicate that there is no dose-associated risk. 2. In the low-dose range for risk assessment, a modified Poisson regression approach that is free of control specifics should be used. 3. The validity of a dose response is characterized by the risks obtained using a dose of occupational exposure. 4. An important issue is the calculation of the risk of radiation-caused diseases with the use of the total dose received by an individual from all types of radiation.

The aim of the study was to assess the radiation risk of death from hypertension in liquidators of the Chernobyl nuclear power plant accident consequences — workers of the nuclear industry — using doses from various types of irradiation. Materials and methods of the study. The study was conducted using data from the Industry Register of Persons exposed to radiation as a result of the Chernobyl accident — workers of the nuclear power industry. Information on 12659 liquidators (all male) was included in the analysis. 1327 of them got occupational radiation doses. Crude relative risks of death from hypertension were estimated for five dose groups using internal controls. Based on the stratified data file, a Poisson regression procedure was performed using the AMFIT module of Epicure program and the excess relative risk of death from hypertension was calculated and the nature of the dose-dependent excess relative mortality was investigated. Results of the study and their analysis. Direct estimates of radiogenic risk of death from hypertension were obtained. No increase in mortality from hypertensive disease per unit dose was found for both the doses received during the liquidation of the Chernobyl accident consequences and for the total doses. The results of the study can be used in the development of radiation safety regulations for persons working with sources of ionizing radiation.

Purpose: Estimate of the excess relative risk of malignant neoplasm disease (MND) in nuclear industry workers, participants in the elimination of the consequences of the Chernobyl accident, taking into account the doses of various types of irradiation. Material and methods: An epidemiological experiment was conducted in which the personal data of the information base of the Industry Register of persons exposed to radiation as a result of the Chernobyl accident, the doses of occupational exposure, and tabular data on the dose of natural exposure, presented in the reports on the radiation situation in populated areas ESKID, No. 4-DOZ) were used. Results: It is shown that the risk assessment of the disease in the Chernobyl accident liquidators, obtained with the use of doses of different types of exposure, has different risk indicators (ERR at 1 Sv: the Chernobyl NPP radiation dose is 0.13, the ChNPP + professional dose is 1.13 and the ChNPP dose + professional + natural – 0.56). Conclusions: – Using any part of the total radiation dose of a person to calculate the risk of dose-induced diseases, we will get incorrect results is unknown how far from the truth. – For a reliable assessment of the risk of the disease, an overall dose is required from a person from all types of radiation, which is required by the radiation safety directives.