The ecological half-life of 137Cs was calculated individually for four symbiotrophic fungi species (Boletus edulis, Imleria badia, Suillus luteus, Paxillus involutus) at 10 sampling sites in the Chornobyl exclusion zone and Kyiv region. It found that maximum rate excretion from organisms is characteristic territory with levels soil contamination, i.e., a near Nuclear Power Plant. In areas low c...