Lifetime prognosis of mortality radiation risks among participants in the consequences of the Chernobyl accident

In accordance with the provisions of Federal Law No. 329FZ dated December 30, 2012, one of the main tasks of the National Radiation and Epidemiological Registry (NRER) state information system is to predict the medical radiological consequences of the Chernobyl accident, including longterm consequences. The purpose of this study is to assess the degree of conservativeness of the radiation risk models identified in the NRER studies for the Russian cohort of liquidators, compared with the models recommended by the ICRP, the UNSCEAR and the AmericanJapanese Radiation Effects Research Foundation (RERF) for solving radiation protection problems at the global level. A comparative analysis of the projected mortality radiation risks calculated using the NRER models and reputable international organizations has shown that conservative (highest) estimates of lifetime mortality radiation risks from solid malignant neoplasms, diseases of the circulatory system and respiratory diseases are provided by NRER models, and for mortality radiation risks from leukemia (excluding cases of chronic lymphocytic leukemia) – UNSCEAR models. The conservative estimate of the lifetime radiation risk of mortality from solid malignant neoplasms in the cohort of liquidators (according to the NRER model) is 1.7 times higher than the estimate obtained for the same cohort using the nominal radiation risk of mortality of the ICRP. For mortality from leukemia, the conservative estimate of lifetime radiation risk (according to the UNSCEAR model) is 1.4 times higher than the estimate obtained using the corresponding nominal risk coefficient of the ICRP. Further research from the point of view of application to the tasks of radiation protection in emergency situations requires a lifetime radiation risk of mortality from nononcological diseases, which is 2.3 times higher than the corresponding risk for malignant neoplasms. Thus, for the Russian cohort of liquidators, the nominal coefficients of radiation mortality risks of the ICRP, laid down in the foundations of radiation safety standards, significantly underestimate the severity of the longterm radiological consequences of the Chernobyl accident.