Comparing the risk of mortality from solid cancer after radiation incidents and occupational radiation exposure

Abstract

The purpose of the study is to compare the excess relative risk (ERR per 1 Sv) of solid cancer mortality in acute - catastrophic or emergency, and occupational - fractionated or chronic exposure. Materials and research methods. A maintained database (database of sources) on nuclear workers from about 40 countries, on the basis of it a combined data analysis was carried out to determine the integral ERR value per 1 Gy for cancer mortality for comparison with parameters of cohorts exposed to catastrophic and emergency exposure: the LSS cohort victims of the atomic bombings in Japan, residents of the Techa River (radioactive contamination due to emissions from the Mayak plant) and Russian liquidators of the Chernobyl accident. Results. Comparison of the ERR per 1 Sv for cancer mortality for workers in the global nuclear industry (combining analysis of data from 37 studies) with the parameters of the LSS cohort, residents on the Techa River and liquidators of the Chernobyl accident showed the absence of logical and principial differences, and the risks for the last two cohorts were the highest. Although the data obtained partly confirm the approach of recent years by the United Nations Scientific Committee on the Effects of Atomic Radiation, according to which the carcinogenic effects of acute, accidental, and fractionated or chronic radiation exposure do not depend on the dose rate factor (DDREF), nevertheless, taking into account biological mechanisms and data radiobiological experiments, this issue cannot be considered unambiguously resolved. Conclusion. Based on the ERR per 1 Sv, the average external dose, and the annual background cancer mortality in Russia and the United States, the expected increase in cancer mortality for 100,000 nuclear workers will average 32-69 people over 10 years (0.032-0.069% of the group). Such risks, due to the many carcinogenic non-radiation factors of life and work, as well as fluctuations in the background value, cannot be taken into account in the practice of medicine and health care.