Chernobyl still with us: 137Caesium activity contents in seabed sediments from the Gulf of Bothnia, northern Baltic Sea

Elevated levels of 137Caesium (137Cs) from the Chernobyl nuclear accident persist in subsurface sediments across the Gulf of Bothnia, Baltic Sea, despite overall declines due to radioactive decay. Highest concentrations (>4000 Bq kg−1) are found in coastal and estuarine areas, which also face significant anthropogenic pressure. The study analyzed 56 sediment cores, revealing that post-Chernobyl sedimentation rates ranged from 0.1 to 4.8 cm/year, averaging 0.54 cm/year. These findings highlight the lingering environmental impact of Chernobyl and underscore the utility of 137Cs in tracking sedimentation rates. The research provides critical insights into the long-term ecological consequences of nuclear fallout in marine ecosystems.

Kotilainen, A. T., Kotilainen, M. M., Vartti, V.-P., Hutri, K.-L., & Virtasalo, J. J. (2021). Chernobyl still with us: 137Caesium activity contents in seabed sediments from the Gulf of Bothnia, northern Baltic Sea. Marine Pollution Bulletin, 172, 112924. https://doi.org/10.1016/j.marpolbul.2021.112924