Excretion of 137Сs from silver Prussian carp (Carassius gibelio) at 5 °С water temperature

Abstract

After the accidents at Chernobyl and Fukushima-1 nuclear power plants, the radioactive contamination of fish can still exceed the permissible levels of radionuclides in food. In order to predict the radioactive contamination of fish, the parameterization of mathematical models is the basis for radiation protection of humans and the environment. Until recently, there were no parameters of radiocaesium metabolism which is the rate of uptake and excretion of radionuclides from fish at a water temperature below 8 10 ° С during winter season. The aim of this work was to determine the rate of 137 Cs excretion (biological half-life) from the silver Prussian carp (Carassius gibelio) at a water temperature of 5±1 ° C under controlled conditions in aquarium. As a result of experimental studies, the values of the 137 Cs biological half-life were obtained from the silver Prussian carp (392±206 days) in the absence of feeding at a water temperature of 5±1 °C. That corresponds to the values previously obtained by us in similar conditions after the radioactive contamination of fish in the environment of the Chernobyl Exclusion Zone 433±162 days. When describing the dynamics of a decrease of the 137 Cs activity concentration in the body of silver Prussian carp with double exponential dependence, the proportion of the fast component of the radionuclide content decrease was 19±3%. In this case, the fast and slow rates of 137 Cs excretion from the body of the fish were equal to 0.3±0.2 days -1 and 0.0004±0.0003 days -1 , respectively. The results obtained in the work show that the level of radioactive contamination of fish will be constant during the winter season. And its seasonal decrease in winter (according to the sawtooth dependence), usually expected out of projected estimates, does not happen. That was also confirmed by the results and experimental data obtained in the environment of the Chernobyl Exclusion Zone.