Accumulation of radiocaesium in fungi

The accumulation of radioactive Cs by fungi was studied by analysis of fruit bodies (n (total) = 205, n greater than or equal to 5 for 22 species) collected in 1988 in a Norwegian mountain area with high deposition of radiocaesium from the Chernobyl accident. To account for site variation, the radiocaesium content of soil and plants was determined for each sampling spot. The soil contained 5-600 kBq/m2 (median = 50 kbq/m2, 134Cs + 137Cs). The plant content ranged from 0.25 to 23 Bq/g dry weight (median = 3.1 Bq/g) and was positively correlated with radiocaesium concentration in the soil (r = 0.56) and negatively correlated with soil pH (r = -0.28). The ratio between radiocaesium content in fungi and that in plants at the same spot (F/P) differed among species: 25 species had F/P values between 30 and 270, 12 species had F/P values between 10 and 30, and the rest (16 species) had F/P values below 10 (only four samples had values below 1). The concentration of nonradioactive Cs in fruit bodies was positively correlated with their radiocaesium content. Certain species selectively accumulated one or several trace elements (V, Cd, Hg, Pb, Th).