- Journal of Radiation Research 編集委員会
- Journal of Radiation Research (ISSN:04493060)
- vol.45, no.2, pp.325-332, 2004 (Released:2004-08-10)
Mushrooms are known to accumulate radiocesium. To estimate the intake of radiocesium through the eating of mushrooms, about 30 samples belonging to 4 commonly consumed species (Lentinula edodes, Hypsizigus marmoreus, Grifola frondosa, and Tricholoma matsutake), were analyzed for 137Cs and 40K. The concentration ranges were 0.060-29 Bq kg-1 (wet wt) for 137Cs and 38-300 Bq kg-1 (wet wt) for 40K. The geometric mean concentration for 137Cs was 0.56 Bq kg-1 (wet wt), and the mean concentration for 40K was 92 Bq kg-1 (wet wt). The 137Cs concentrations in L. edodes cultivated in mushroom beds (sawdust-rice bran media) were lower than those cultivated on bed logs (natural wood with bark). The annual intake of 137Cs per person through mushrooms was calculated, by using the current analytical results and food consumption data in Japan, to be 3.1 Bq for 137Cs, which is about 28% of the total dietary intake of this nuclide. The effective dose equivalent of 137Cs through mushrooms was estimated to be 4.0 ¤ 10-8 Sv, which is about the half the value obtained in our previous study. The decrease of the 137Cs intake through mushrooms is probably related to changes in cultivation methods in recent years, from the use of bed logs to mushroom beds.