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Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
KEK Proceedings 2021-2, p.91 - 96, 2021/12
We examined whether the ESR dose estimation method could be applied to wild Japanese macaque. In this work, we investigated the enamel preparation protocol and the analytical method of the ESR spectra.
Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.
Radiation Measurements, 134, p.106315_1 - 106315_4, 2020/06
Times Cited Count：5 Percentile：53.85(Nuclear Science & Technology)The relationship between the CO
radical intensity and the absorbed dose (dose response curve) of tooth enamel of Japanese macaque was observed by electron spin resonance and the detection limit of our system was estimated to be 33.5 mGy, which is comparable to the detection limit for human molar teeth. Using the dose response curve, external exposure dose for seven wild Japanese macaques captured in Fukushima prefecture were examined. The results suggest that the external exposure dose for the wild Japanese macaques were ranged between 45 mGy to 300 mGy.
), a vertebrate modelYasuda, Takako*; Oda, Shoji*; Hibi, Yusuke*; Urushihara, Yusuke*; Mitani, Hiroshi*; Funayama, Tomoo; Yokota, Yuichiro; Muto, Yasuko; Ikeda, Hiroko; Kobayashi, Yasuhiko
no journal, ,
Using heavy-ion microbeam system of JAEA-Takasaki, we irradiated brain of the embryos of the Medaka with carbon ion microbeam. After irradiation, inductions of apoptosis were observed using whole-mount staining of acridine orange. In targeted position of the brain, we observed the induction of radiation induced apoptosis, indicating that the system can irradiate specific region of the brain of the Medaka embryo.
Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Ono, Takumi*; Tamaki, Hiroaki*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; et al.
no journal, ,
Releases of the radioactive materials from the Fukushima Daiichi Nuclear Power Plant accident result in an ionization exposure to people and animals, the precise dosimetry is required. To estimate the external dose due to the accident, we utilize electron spin resonance (ESR) spectroscopy which is a powerful tool for the dosimetry of external dose. The detection limit of this technique was 146 mGy, so that we have to improve the detection limit for the precise dosimetry. In this work, we developed a novel enamel-dentine separation technique and improved the detection limit down to 43 mGy, and estimated the external dose for Japanese macaque and Procyon lotor collected in Fukushima prefecture.
Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Ono, Takumi*; Tamaki, Hiroaki*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
no journal, ,
Release of the radioactive materials from Fukushima Daiichi Nuclear Power Plant accident results in a long-term low dose rate ionization exposure to wild animals. The biological effects of the wild animal do not show a clear correlation with the external dose, which is estimated from the external dose rate of the captured point of the animal, a precise external dose estimation using ESR and tooth enamel is required instead of using the external dose rate. In this work, we attempted to estimate the external dose of wild Japanese macaque and Procyon lotor captured in the high dose rate area.
Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Mitsuyasu, Yusuke*; Kino, Yasushi*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; Suzuki, Toshihiko*; Osaka, Ken*; et al.
no journal, ,
Due to the Fukushima Daiichi Nuclear Power Plant accident, the exposure dose estimation for human is examined by the whole body counter or by the Fukushima Health Management Survey, however, the precise estimated dose cannot obtained by such methods. We applied electron spin resonance (ESR) dosimetry for the external dose estimation using tooth enamel of human/animal. As we reported last year, we improved the detection limit of ESR dosimetry down to 43 mGy. We used this improved ESR dosimetry system and attempted to estimate the external dose of wild Japanese macaque capture in Fukushima prefecture, however, the metal component which may obstruct the ESR measurement was observed, so that we cannot estimate the external dose. In this work, we investigated how to remove such metal components, obtain the clear ESR spectrum, and estimate the external dose.
Oka, Toshitaka; Mitsuyasu, Yusuke*; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Sekine, Tsutomu*; Okutsu, Kenichi*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
no journal, ,
Releases of the radioactive materials from the Fukushima Daiichi Nuclear Power Plant accident result in a low dose exposure to wild animals. The external dose of wild animals is commonly estimated by the external dose rate of the captured point, but the estimated exposure dose has huge uncertainties because the size of the habitat and/or the movement of the wild animals are not included in the estimation. To estimate the external dose precisely, we utilize electron spin resonance (ESR) dosimetry. In this work, we investigated the sample preparation procedure of wild animals. The ESR spectrum of enamel of racoon captured in Namie-town, Fukushima has a broad ESR signal due to metal components. The linear relationship between the Co intensity and the absorbed dose that we can apply ESR dosimetry for racoon teeth. Using this relationship, the external exposure dose was estimated.
Mitsuyasu, Yusuke*; Oka, Toshitaka; Takahashi, Atsushi*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Sekine, Tsutomu*; Yamashita, Takuma*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
no journal, ,
The improvement of the ESR dosimetry is required to apply that for the low-dose exposure of wild animals. We will report our progress of the improvement, and compare the external exposure dose estimated by the ESR dosimetry technique and the calculated result based on the external exposure dose rate of the captured point.
Oka, Toshitaka; Takahashi, Atsushi*; Mitsuyasu, Yusuke*; Koarai, Kazuma; Kino, Yasushi*; Okutsu, Kenichi*; Yamashita, Takuma*; Sekine, Tsutomu*; Shimizu, Yoshinaka*; Chiba, Mirei*; et al.
no journal, ,
Electron spin resonance (ESR) dosimetry technique is a powerful tool that has been used in the study of external exposure dose assessment of human by measuring CO radicals of teeth. In this work, we applied this technique for wild monkey and wild racoon captured in Fukushima prefecture, and estimated the external exposure dose.
