LEVELS OF RADIONUCLIDE CONTAMINATION OF FISH OF VERSHYNA LAKE IN THE CHORNOBYL EXCLUSION ZONE

The levels of specific activity of 90Sr and 137Cs in fish of one of the most polluted reservoirs of the Chornobyl Exclusion Zone (ChEZ) - Vershyna Lake. During the research period from 2011 to 2021 for all studied fish of the lake. The peak ranges of the specific activity of radionuclides are noted at the level of 32960-213300 (average value 67832-22936) Bq/kg for 90Sr and 838-25907 (4811-569) Bq/kg for 137Cs. It is shown that at the current stage, the specific activity of 90Sr in the ichthyofauna of the lake exceeds the permissible levels, which are accepted in Ukraine for fish products in more than 942-6094, and 137Cs - in 6-173 times. The 90Sr/137Cs ratio in lake fish is in the range of 3-108. The distribution of radionuclides in the organs and tissues of silver crucian carp is given. Estimated dose rate of fish irradiation of the Vershyna Lake. As shown by the results of studies of the ichthyofauna of Vershyna Lake , the maximum average dose rate irradiation was noted in representatives of bentophagous Prussian carp (149,5-12,1 ?Gy/h), the minimum - in the pelagic Sunbleak (56,2-5,1 ?Gy/h). It was noted, that 90Sr is the dominant radionuclide in the formation of the total radiation dose of fish from Vershyna Lake (in contrast to all other investigated reservoirs of the ChEZ).