Baltic Sea: Radionuclides

Sven Poul Nielsen, Maria Lüning, Erkki Ilus, Iisa Outola, Tarja Ikäheimonen, Jukka Mattila, Jürgen Herrmann, Günter Kanisch, Iolanda Osvath

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    The most significant source of anthropogenic radioactivity in the Baltic Sea is fallout from the accident at the Chernobyl nuclear power plant in 1986. The second most important source is global fallout from atmospheric nuclear weapons tests carried out during the late 1950s and early 1960s. Radioactivity inputs into the Baltic Sea from nuclear reprocessing plants in Western Europe have become of minor importance due to significant reduction of discharges in recent years. In terms of input of 137Cs into the Baltic Sea, Chernobyl fallout has contributed about 82% and nuclear weapons test fallout about 14%. For 90Sr in the Baltic Sea, input from atmospheric fallout from nuclear weapons tests has contributed about 81%, while the contribution from Chernobyl fallout was about 13%. Cesium-137 is the main indicator of Baltic seawater with respect to anthropogenic radioactivity. The highest concentrations in seawater during 1999–2006 were found in the Baltic Proper and the Bothnian Sea. The general trend is steadily decreasing. Concentrations of anthropogenic radioactivity in fish generally show decreasing trends in agreement with concentrations in seawater. Among freshwater fish, pike showed large 137Cs values due to their higher concentration factors (CFs). The larger 137Cs values of pike were observed at the coast of the Bothnian Sea. The Baltic Sea is the regional sea in the world with the highest concentrations of 137Cs. The Baltic Sea ranks third in the world with respect to 90Sr in seawater; only the Irish Sea and the Black Sea show higher levels. In 1990, average concentrations of 137Cs in fish from the Baltic Sea were similar to those in the Irish Sea, about 4 times higher than in the Black Sea and about 30 times higher than in the Mediterranean Sea.
    Original languageEnglish
    Title of host publicationEncyclopedia of Inorganic Chemistry
    EditorsRobert H. Crabtree
    Publication date2010
    Edition2nd ed.
    Publication statusPublished - 2010


    • Radiation research and nuclear technologies
    • Radioecology and tracers

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