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Tokonami S, Miura T, Akata N, Tazoe H, Hosoda M, Chutima K, Kudo H, Ogura K, Fujishima Y, Tamakuma Y, Shimizu M, Kikuchi K, Kashiwakura I. Support activities in Namie Town, Fukushima undertaken by Hirosaki University. Ann ICRP 2021; 50:102-108. [PMID: 34092120 DOI: 10.1177/01466453211006806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This paper does not necessarily reflect the views of the International Commission on Radiological Protection.Several radiation monitoring research projects are underway on dose assessment, biological analysis, and risk communication under an agreement with Namie Town. Indoor radon and thoron progeny concentrations have been measured using passive-type monitors to estimate internal doses due to inhalation. In addition, airborne radiocaesium concentrations at five points in Namie Town have been analysed using a high-purity germanium detector to estimate internal doses for comparison with radon. External radiation doses from natural and artificial radionuclides have also been estimated using an in-situ gamma-ray spectrometer. Other support activities are mentioned briefly in this article.
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Affiliation(s)
- Shinji Tokonami
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Tomisato Miura
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Naofumi Akata
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Hirofumi Tazoe
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Masahiro Hosoda
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail: .,Hirosaki University Graduate School of Health Sciences, Japan
| | - Kranrod Chutima
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Hiromi Kudo
- Hirosaki University Graduate School of Health Sciences, Japan
| | - Koya Ogura
- Hirosaki University Graduate School of Health Sciences, Japan
| | - Yohei Fujishima
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Yuki Tamakuma
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Mayumi Shimizu
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
| | - Kazutaka Kikuchi
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan; e-mail:
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Transition of Radioactive Cesium Deposition in Reproductive Organs of Free-Roaming Cats in Namie Town, Fukushima. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041772. [PMID: 33670348 PMCID: PMC7918855 DOI: 10.3390/ijerph18041772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 11/17/2022]
Abstract
We investigated the internal contamination by radioactive cesium associated with the FDNPP accident, in the testes or uterus and ovaries of free-roaming cats (Felis silvestris catus), which were protected by volunteers in the Namie Town, Fukushima. A total of 253 samples (145 testes and 108 uterus and ovaries) obtained from adult cats and 15 fetuses from 3 pregnant female cats were measured. Free-roaming cats in Namie Town had a higher level of radioactive contamination in comparison to the control group in Tokyo, as the 134Cs + 137Cs activity concentration ranged from not detectable to 37,882 Bq kg-1 in adult cats. Furthermore, the radioactivity in the fetuses was almost comparable to those in their mother's uterus and ovaries. The radioactivity was also different between several cats protected in the same location, and there was no significant correlation with ambient dose-rates and activity concentrations in soil. Moreover, radioactive cesium levels in cats decreased with each year. Therefore, it is likely that decontamination work in Namie Town and its surroundings could affect radioactive cesium accumulation, and thus possibly reduce the internal radiation exposure of wildlife living in contaminated areas. It is hence necessary to continue radioactivity monitoring efforts for the residents living in Namie Town.
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Anderson D, Beresford NA, Ishiniwa H, Onuma M, Nanba K, Hinton TG. Radiocesium concentration ratios and radiation dose to wild rodents in Fukushima Prefecture. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 226:106457. [PMID: 33227677 DOI: 10.1016/j.jenvrad.2020.106457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/04/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
Radiocesium was dispersed from the Fukushima Dai-ichi disaster in March 2011, causing comparatively high radioactive contamination in nearby environments. Radionuclide concentrations in wild rodents (Apodemus argenteus, and Apodemus speciosus) within these areas were monitored from 2012 to 2016. However, whole-organism to soil transfer parameters (i.e., concentration ratio, CRwo-soil) for wild rodents at Fukushima were not determined and hence were lacking from the international transfer databases. We augmented the 2012-2016 data by collecting soil activity concentrations (Bq kg-1, dry mass) from five rodent sampling sites in Fukushima Prefecture, and developed corresponding CRwo-soil values for radiocesium (134Cs and 137Cs) based on rodent radioactivity concentrations (Bq kg-1, fresh mass). The CRwo-soil were added to the Wildlife Transfer Database (WTD; http://www.wildlifetransferdatabase.org/), supporting the development of the International Commission on Radiological Protection's (ICRP) environmental protection framework, and increasing the WTD from 84 to 477 entries for cesium and Muridae ('Reference Rat'). Significant variation occurred in CRwo-soil values between study sites within Fukushima Prefecture. The geometric mean CRwo-soil, in this paper, was higher than that reported for Muridae species for Chernobyl. Radiocaesium absorbed dose rates were also estimated for wild rodents inhabiting the five Fukushima study sites and ranged from 1.3 to 33 μGy h-1. Absorbed dose rates decreased by a factor of two from 2012 to 2016. Dose rates in highly contaminated areas were within the ICRP derived consideration reference level for Reference Rat (0.1-1 mGy d-1), suggesting the possible occurrence of deleterious effects and need for radiological effect studies in the Fukushima area.
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Affiliation(s)
- Donovan Anderson
- Symbiotic Systems Science and Technology, Fukushima University, Fukushima, Fukushima City, Kanayagawa, 960-1248, Japan.
| | - Nicholas A Beresford
- UK Centre for Ecology & Hydrology, Lancaster Environment Center, Library Av., Bailrigg, Lancaster, LA1 4AP, UK
| | - Hiroko Ishiniwa
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, Fukushima City, Kanayagawa, 960-1248, Japan
| | - Manabu Onuma
- Ecological Risk Assessment and Control Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-0053, Japan
| | - Kenji Nanba
- Symbiotic Systems Science and Technology, Fukushima University, Fukushima, Fukushima City, Kanayagawa, 960-1248, Japan; Institute of Environmental Radioactivity, Fukushima University, Fukushima, Fukushima City, Kanayagawa, 960-1248, Japan
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, Fukushima, Fukushima City, Kanayagawa, 960-1248, Japan; Centre for Environmental Radioactivity, CoE, Norwegian University of Life Sciences, Faculty for Environmental Sciences and Nature Research Management, 1430, Åas, Norway
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