137Cs activity concentrations in mushrooms collected from two different types of habitats in Finnish Lapland

Full text: 137Cs activity concentrations from thirteen different mushroom species collected from the Kivalo Research Area in Northern Finland were analysed at the Radiation and Nuclear Safety Authority (STUK) in the Regional Laboratory in Northern Finland. The analyzed samples were collected from 1989 to 2008 from four types of forest, which were divided into two classes - fresh heath and dry heath - based on their properties as a habitat. The aim of this study was to compare the 137Cs levels in the same mushroom species collected from the different habitats. In addition, the ecological half-lives for the different species were estimated. Together 360 samples were analysed by gamma spectrometry. The results were processed statistically and the significance of the habitats was evaluated to nine different mushroom species. The impact of habitats could be observed inside the same species. 137Cs activity concentrations in mushrooms were higher on the fresh heath than on the dry heath, with the exception of Cortinarius armillatus and Suillus variegatus. 137Cs concentration levels in Bq/kg f.w. were under 50 in Leccinum, under 150 in Russula, under 300 in Lactarius and Suillus, under 400 in Cortinarius armillatus and under 700 in Rozites caperatus. The concentration was found to be over the EC recommendation of 600 Bg/kg in one sample which was Cortinarius armillatus in 1994. (LN)