Scientific publications

This article presents a comprehensive assessment of the radioecological state of bottom sediments in the northeastern part of the Barents Sea. The study is based on data obtained during the marine expedition “Arctic Floating University” in July 2024. Specific activities of anthropogenic 137Cs and natural 226Ra, 232Th, and 40K radionuclides were determined in the top 3-cm layer of sediments collected at 39 oceanographic stations. The average activities were 1.9 Bq/kg for 137Cs, 20.5 Bq/kg for 226Ra, 28.4 Bq/kg for 232Th, and 655.9 Bq/kg for 40K. The levels of anthropogenic radioactive contamination, proxied by 137Cs activity, are characterized as extremely low, below the average values for the Barents Sea. The data indicate the absence of recent inputs and a general declining trend in anthropogenic radioactive contamination. The activities of natural radionuclides fall within the ranges characteristic of the region. Correlation analysis revealed strong alignment between 226Ra, 232Th, and 40K, as well as their dependence on grain size composition and organic matter content. In contrast to natural radionuclides, the accumulation of 137Cs is primarily controlled by local lithological and geochemical conditions rather than by water depth. Calculations of radiological safety indices showed that the current levels of natural radioactivity pose no threat to marine ecosystems. The results provide a relevant background framework for monitoring the Arctic shelf in the context of its planned industrial development and ongoing climate change.