著者

Ban-nai Tadaaki Muramatsu Yasuyuki Yoshida Satoshi

出版者

日本放射線影響学会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.45, no.2, pp.325-332, 2004-06-15

被引用文献数

1 13

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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, Hyp-sizigus marmoreus, Grifola frondosa, and Tricholoma matsutake), were analyzed for ^<137>Cs and 40K. The concentration ranges were 0.060-29 Bq kg^<-1> (wet wt) for ^<137>Cs and 38-300 Bq kg^<-1> (wet wt) for ^<40>K. The geometric mean concentration for ^<137>Cs was 0.56 Bq kg^<-1> (wet wt), and the mean concentration for ^<40>K was 92 Bq kg^<-1> (wet wt). The ^<137>Cs 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 ^<137>Cs per person through mushrooms was calculated, by using the current analytical results and food consumption data in Japan, to be 3.1 Bq for ^<137>Cs, which is about 28% of the total dietary intake of this nuclide. The effective dose equivalent of ^<137>Cs 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 ^<137>Cs intake through mushrooms is probably related to changes in cultivation methods in recent years, from the use of bed logs to mushroom beds.

著者

OHNO TAKESHI MURAMATSU YASUYUKI MIURA YOSHINORI ODA KAZUMASA INAGAWA NAOYA OGAWA HIROMU YAMAZAKI ATSUKO TOYAMA CHIAKI SATO MUTSUTO

出版者

GEOCHEMICAL SOCIETY OF JAPAN

雑誌

GEOCHEMICAL JOURNAL (ISSN:00167002)

巻号頁・発行日

vol.46, no.4, pp.287-295, 2012

被引用文献数

74

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In order to understand the behavior of radionuclides released from the Fukushima Daiichi nuclear power plant, the depth distributions of radiocesium and radioiodine were investigated in a wheat field, a rice paddy, an orchard, and a cedar forest in Koriyama, Fukushima Prefecture. Our results demonstrate that, following the nuclear power plant disaster, more than 90% of the radionuclides were distributed in the upper 6 cm of the soil column in the wheat field and within 4 cm of the surface in the rice paddy, orchard, and cedar forest. According to the measurement of radionuclides in the three adjacent agricultural fields, the variation of deposition densities in the wheat field was smaller than that of the orchard and rice paddy, suggesting that the low permeability of the orchard and paddy soils may cause horizontal migration of radionuclides during the initial deposition. This result indicates that the deposition densities in the wheat field should be appropriate for estimating the amount of fallout in the area. The deposition densities of ¹³⁴Cs, ¹³⁷Cs, and ¹³¹I in this area were estimated to be 512 ± 76 (SD, <i>n</i> = 5), 522 ± 80 (SD, <i>n</i> = 5), and 608 ± 79 (SD, <i>n</i> = 5) kBq/m² (decay corrected to April 1, 2011), respectively. A comparison of the deposition density between the wheat field and the cedar forest suggests that more than half of the radionuclides are distributed in the tree canopies of the evergreen forestland.