Накопление радионуклидов в рыбе из рек северо-западного сектора российской Арк­тики

Abstract

The article presents the analysis of the radionuclide content in fish (perch — Perca fluviatilis L., pike — Esox Lucius L.) living in the rivers (Mezen, Nes and Pechora) of the northwestern sector of the Arctic zone of Russia. In one of the rivers of the study region (the Nes River in the Nenets Autonomous Area), the researchers have revealed the presence of technogenic radionuclides Cs-137 and Sr-90. To assess the distribution of these radionuclides in the fish body, they divided the selected fish samples into separate biological systems: muscle tissue, bone tissue, heads, entrails, a mixture of skin, scales and fins. The largest amount of Cs-137 is contained in the fish muscle tissue (more than 50% of the total radionuclide activity). The greatest amount of Sr-90 is contained in a mixture of skin, scales, fins (47%) and heads (33%) of river perch, while this radionuclide is absent in pike samples. There is a small content of Sr-90 in the bone tissue of river perch. In the absence of other technogenic short-lived radionuclides, the likely reason for the presence of Cs-137 and Sr-90 in the fish of the Nes River is a radioactive trace that appeared during nuclear tests on the Novaya Zemlya archipelago. The main dose-forming radionuclide in the selected fish samples was natural K-40. Its content for pike is estimated at 92% of the total beta activity, for river perch — 86%. The main content of this radionuclide falls on muscle tissue (about 50% for pike and river perch). According to the research results, it is noted that the levels of radioactivity in fish from the Nes River do not exceed the sanitary and hygienic standards established in the Russian Federation in the field of food safety and do not pose a significant radiological risk to the population.