@misc{oai:repo.qst.go.jp:00067462,
 author = {Ban-nai, Tadaaki and Yoshida, Satoshi and Muramatsu, Yasuyuki and 坂内 忠明 and 吉田 聡 and 村松 康行},
 month = {Sep},
 note = {After the Chernobyl accident, high concentrations of radiocesium in mushrooms were found in many countries, mainly in Europe. In our previous researches, we found that 137Cs concentrations in mushrooms collected in forest were markedly higher than autotrophic plants. In our previous study, we calculated the contribution of mushrooms in Japan (on average) as 32% of the total intake for 137Cs, while that for 40K was only 1.7%. Therefore, mushrooms are thought to be important for an estimation of internal radiation dose from 137Cs through foods. It is important for radiation protection and radioecology to understand the behavior of radionuclides in mushrooms. 
Accumulation of radiocesium in fruit body of mushrooms was also observed by laboratory experiment. We carried out the cultivation experiment of 4 basidiomycetes (Hebeloma vinosophyllum, Flammulina velutipes, Coprinus phlyctidosporus and Agrocybe cylindracea) in the medium including 137Cs and other radionuclides (85Sr, 60Co, 54Mn and 65Zn) as a radiotracer. This result showed that fruit bodies of 4 basidiomycetes accumulate Cs from medium, although there was a large difference between mushroom species.
However, there is almost no information on the Cs accumulation in hypha. Behavior of radiocesium between hypha and fruit bodies is also unclear. In this study, transfer of 137Cs from medium to hypha of basidiomycetes was estimated by using cultivation experiments in flasks. 65Zn is also used for comparison. Four species, H. vinosophyllum, A. cylindracea, Lentinula edodes and Pleurotus ostreatus were used. Accumulations of 137Cs and 65Zn in hypha were observed in some species. In order to compare the ability of basidiomycetes on accumulation of radionuclides, the concentration rate, which was defined as "activity of radionuclide in hypha of mushroom (Bqg-1, wet wt.)" divided by "activity of radionuclide in medium at the beginning of the experiments (Bq g-1, wet wt.)", was calculated, The concentration rate of fruit body obtained by the previous study were also shown in Figure. The concentration ratio of 137Cs ranged from 0.40 to 3.9. The highest value of 3.9 was observed for P. ostreatus. The ratios for hypha were lower than those observed for fruit bodies in previous studies. These findings suggested that Cs taken up by hypha was moved and accumulated into fruit body during fruit body formation., 第16回国際環境生物地球化学シンポジウム},
 title = {Uptake of radiocesium by hypha of basidiomycetes -radiotracer experiments-},
 year = {2003}
}