LAUSR

Introduction The accident at the Chernobyl nuclear power plant was the most huge radiation and ecological catastrophe. About 100,000 Belarusian citizens took part in the liquidation of the Chernobyl accident. During the first years after the accident, the growth of incidence of malignant neoplasms of blood of the affected population was predicted. But till now, there is no clear conclusion about the contribution of the radiation factor to the incidence of leucosis and lymphomas. The purpose of the study was to analyse the features of forming the incidence of malignant neoplasms of the blood and lymphatic system of the liquidators of the Chernobyl accident in the Republic of Belarus. Material and methods The data of the Chernobyl State Register of persons exposed to radiation following the Chernobyl catastrophe for the period from 1987 to 2015 were used (99 498 liquidators). The epidemiological analysis of the incidence of leukemias, lymphomas and multiple myeloma was made using the standardised incidence ratio (SIR). Liquidators were analysed by sex, age at time of the disaster, year of work, duration of staying in contaminated area, density of radiation contamination and individualised doze in bone marrow. Results and discussions The excess of incidence of leukemias in the cohort of liquidators of the Chernobyl accident was noted. The excess fraction of leukemias was about 20%–40% (SIR=1.3 (1.2–1.46)). It was shown that the high risk of leukaemia was formed due to chronic lymphocytic (SIR=1.3 (1.14–1.53)) and myelocytic (SIR=1.7 (1.35–2.03)) leukemias regardless of the status of a liquidator. There was also no clear dependence between the risk of hemoblastosis and the density of contamination, as well as the individualised absorbed dose on the blood marrow. However, it can be stated that a large proportion of cases of multiple myeloma (32%) was found in the liquidators who performed their work in the territory with the Cs137 pollution density of more than 40 Ku/km2 (SIR=1.8 (1.16–2.8)). Conclusion The conducted research allowed to characterise the risks of development of various forms of hemoblastosis in liquidators and to show trends in the distribution of incidence of certain their forms.