Concentrations of Cs-137 and K-40 in edible mushrooms collected in Japan and radiation dose due to their consumption

To estimate radiocesium intake due to eating mushrooms, about 100 samples belonging to 11 species were analyzed to establish representative values for Cs-137 and K-40 in common edible mushrooms available in food markets. Concentration ranges were <0.047-39 Bq kg(-1) (wet wt) for Cs-137 and 30-210 Bq kg(-1) (wet wt) for K-40. The median concentrations mere 1.3 Bq kg(-1) (wet wt) for Cs-137 and 97 Bq kg(-1) (wet wt) for K-40. The Cs-137 concentrations in cultivated mushrooms were markedly lower than those in wild mushrooms. The annual intake of Cs-137 per person through mushrooms was calculated (using analytical results and food consumption data in Japan) to be 6.0 Bq for Cs-137, which is about 32% of the total dietary intake of this nuclide. The effective dose equivalent of Cs-137 through mushroom was estimated to be 7.7 x 10(-8) Sv (range estimated from the standard deviation: 3.0 x 10(-8)-2.0 x 10(-7)).