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The excretion of 137Cs from silver prussian carp (Carassius gibelio) with different water temperature under nature conditions in the Chernobyl exclusion zone

After the accident at the Chernobyl nuclear power plant, the activity concentration of radionuclides in fish reached hundreds of kBq kg-1. Determination in the dynamics of the content of radionuclides in the body of fish is necessary for the radiation protection of humans and the environment. The data presented in the literature are extremely contradictory and such large differences in the main parameters of radionuclide metabolism in fish require clarification in nature conditions. The aim of this work was to determine the rate of excretion (biological half-life) of 137Cs from the body of silver Prussian carp (Carassius gibelio) at different water temperatures (1-29 °С) depending on the weight of the fish (20±5 and 40±6 g) in real conditions of the Chernobyl Exclusion Zone. As a result of experimental studies, the values of the biological half-life of 137Cs for silver carp was 193-495 days at water temperature 3.7±0.9 °C and 63-92 days at water temperature 22±4 °С were obtained. Due to an increase in the weight of fish (biodilution) at water temperatures > 13 °C, the half-life of the activity concentration of 137Cs in the muscle tissue of fish decreased to 39-58 day-1. The obtained data correspond to the previously obtained values in aquarium experiments. The results obtained in this work show that the level of radioactive contamination of fish in winter will change slightly compared to summer time, which is also confirmed by experimental data obtained in aquarium experiments.