著者

Tomoko M. NAKANISHI

出版者

The Japan Academy

雑誌

Proceedings of the Japan Academy, Series B (ISSN:03862208)

巻号頁・発行日

vol.94, no.1, pp.20-34, 2018-01-11 (Released:2018-01-11)

参考文献数

42

被引用文献数

3

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Immediately after the Fukushima nuclear power plant accident, a team of 40–50 researchers at the Graduate School of Agricultural and Life Sciences at the University of Tokyo began to analyze the behavior of radioactive materials in the fallout regions. The fallout has remained in situ and become strongly adsorbed within the soil over time. 137Cs was found to bind strongly to the fine clay, weathered biotite, and organic matter in the soil; therefore, it has not mobilized from mountainous regions, even after heavy rainfall. In farmland, the quantity of 137Cs in the soil absorbed by crop plants was small. The downward migration of 137Cs in soil is now estimated at 1–2 mm/year. The intake of 137Cs by trees occurred through the bark and not from the roots. This report summarizes the findings of research across a wide variety of agricultural specialties.

著者

Toshinori ARAMAKI Ryohei SUGITA Atsushi HIROSE Natsuko I. KOBAYASHI Keitaro TANOI Tomoko M. NAKANISHI

出版者

公益社団法人 日本アイソトープ協会

雑誌

RADIOISOTOPES (ISSN:00338303)

巻号頁・発行日

vol.64, no.3, pp.169-176, 2015-03-15 (Released:2015-03-28)

参考文献数

23

被引用文献数

3 14

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We performed an imaging analysis of 42K in Arabidopsis using real-time radioisotope imaging system(RRIS). First, we purified 42K from an 42Ar―42K generator. And then, we characterized RRIS performance by quantitatively determining 42K using standard series. As a result, the dynamic range for 42K was determined to be at least three orders of magnitude. Next, we evaluated the level of self-absorption in Arabidopsis organs by comparing the signal intensity detected using RRIS and the actual radioactivity detected by a gamma-counting method. There was no significant difference in detection efficiency between the thick bolt(stem) tissue and the thin leaf tissue. The reason for scarce self-absorption could be related to the relatively strong β ray emissions that have a maximum energy of 3525.4keV.