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Sakai M, Watanabe M, Kanao Koshikawa M, Tanaka A, Takahashi A, Takechi S, Takagi M, Tsuji T, Tsuji H, Takeda T, Jo J, Tamaoki M, Hayashi S. Exploring simple ways to avoid collecting highly 137Cs-contaminated Aralia elata buds for the revival of local wild vegetable cultures. PLoS One 2024; 19:e0292206. [PMID: 38564644 PMCID: PMC10986964 DOI: 10.1371/journal.pone.0292206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 03/16/2024] [Indexed: 04/04/2024] Open
Abstract
Collection and cooking of wild vegetables have provided seasonal enjoyments for Japanese local people as provisioning and cultural ecosystem services. However, the Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused extensive radiocesium contamination of wild vegetables. Restrictions on commercial shipments of wild vegetables have been in place for the last 10 years. Some species, including buds of Aralia elata, are currently showing radiocesium concentrations both above and below the Japanese reference level for food (100 Bq/kg), implying that there are factors decreasing and increasing the 137Cs concentration. Here, we evaluated easy-to-measure environmental variables (dose rate at the soil surface, organic soil layer thickness, slope steepness, and presence/absence of decontamination practices) and the 137Cs concentrations of 40 A. elata buds at 38 locations in Fukushima Prefecture to provide helpful information on avoiding collecting highly contaminated buds. The 137Cs concentrations in A. elata buds ranged from 1 to 6,280 Bq/kg fresh weight and increased significantly with increases in the dose rate at the soil surface (0.10-6.50 μSv/h). Meanwhile, the 137Cs concentration in A. elata buds were not reduced by decontamination practices. These findings suggest that measuring the latest dose rate at the soil surface at the base of A. elata plants is a helpful way to avoid collecting buds with higher 137Cs concentrations and aid in the management of species in polluted regions.
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Affiliation(s)
- Masaru Sakai
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Mirai Watanabe
- National Institute for Environmental Studies, Regional Environmental Conservation Division, Tsukuba, Ibaraki, Japan
| | - Masami Kanao Koshikawa
- National Institute for Environmental Studies, Regional Environmental Conservation Division, Tsukuba, Ibaraki, Japan
| | - Asuka Tanaka
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Akiko Takahashi
- National Institute for Environmental Studies, Regional Environmental Conservation Division, Tsukuba, Ibaraki, Japan
| | - Seiichi Takechi
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Mai Takagi
- National Institute for Environmental Studies, Health and Environmental Risk Division, Tsukuba, Ibaraki, Japan
| | - Takashi Tsuji
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Hideki Tsuji
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Toshimasa Takeda
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Jaeick Jo
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
| | - Masanori Tamaoki
- National Institute for Environmental Studies, Biodiversity Division, Tsukuba, Ibaraki, Japan
| | - Seiji Hayashi
- National Institute for Environmental Studies, Fukushima Regional Collaborative Research Center, Miharu, Fukushima, Japan
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Johansen MP, Anderson D, Child D, Hotchkis MAC, Tsukada H, Okuda K, Hinton TG. Differentiating Fukushima and Nagasaki plutonium from global fallout using 241Pu/ 239Pu atom ratios: Pu vs. Cs uptake and dose to biota. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141890. [PMID: 32916482 DOI: 10.1016/j.scitotenv.2020.141890] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Plutonium (Pu) has been released in Japan by two very different types of nuclear events - the 2011 Fukushima accident and the 1945 detonation of a Pu-core weapon at Nagasaki. Here we report on the use of Accelerator Mass Spectrometry (AMS) methods to distinguish the FDNPP-accident and Nagasaki-detonation Pu from worldwide fallout in soils and biota. The FDNPP-Pu was distinct in local environmental samples through the use of highly sensitive 241Pu/239Pu atom ratios. In contrast, other typically-used Pu measures (240Pu/239Pu atom ratios, activity concentrations) did not distinguish the FDNPP Pu from background in most 2016 environmental samples. Results indicate the accident contributed new Pu of ~0.4%-2% in the 0-5 cm soils, ~0.3%-3% in earthworms, and ~1%-10% in wild boar near the FDNPP. The uptake of Pu in the boar appears to be relatively uninfluenced by the glassy particle forms of fallout near the FDNPP, whereas the 134,137Cs uptake appears to be highly influenced. Near Nagasaki, the lasting legacy of Pu is greater with high percentages of Pu sourced from the 1945 detonation (~93% soils, ~88% earthworm, ~96% boar). The Pu at Nagasaki contrasts with that from the FDNPP in having proportionately higher 239Pu and was distinguished by both 240Pu/239Pu and 241Pu/239Pu atom ratios. However, compared with the contamination near the Chernobyl accident site, the Pu amounts at all study sites in Japan are orders of magnitude lower. The dose rates from Pu to organisms in the FDNPP and Nagasaki areas, as well as to human consumers of wild boar meat, have been only slightly elevated above background. Our data demonstrate the greater sensitivity of 241Pu/239Pu atom ratios in tracing Pu from nuclear releases and suggest that the Nagasaki-detonation Pu will be distinguishable in the environment for much longer than the FDNPP-accident Pu.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Sydney, Australia.
| | - Donovan Anderson
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; Symbiotic Systems Science and Technology, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - David Child
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | | | - Hirofumi Tsukada
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - Kei Okuda
- Faculty of Human Environmental Studies, Hiroshima Shudo University, 731-3195, Hiroshima Prefecture, Asaminami-ku, Ozuka-higashi, Japan
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; CERAD CoE, Norwegian University of Life sciences, Faculty for Environmental Sciences and Nature Research Management, Aas, Norway
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Iwasa M, Nakaya F, Kabeya H, Sato K, Ishikawa SI, Takahashi T. Radiocesium concentrations in invertebrates and their environmental media at two distances from the Fukushima Dai-ichi Nuclear Power Plant during 3-6 years after the 2011 accident. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115657. [PMID: 33254726 DOI: 10.1016/j.envpol.2020.115657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/24/2020] [Accepted: 09/13/2020] [Indexed: 06/12/2023]
Abstract
Activity concentrations of the radioactive cesium (134Cs and 137Cs) were investigated in invertebrates at two sites of moderately high and higher air radiation dose rates, 14 km and 11 km distances, respectively, from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from 2013 to 2016. At a14-km point, the 134+137Cs concentrations of soils in coniferous and broadleaf forests increased from 2013 to 2014, and thereafter declined until 2016. The 134+137Cs concentrations of the phytophagous beetle Anomala cuprea (Hope) rapidly decreased by 76.1% from 2013 to 2014, reflecting reduction in those of broadleaves. The 134+137Cs concentration levels of the carnivorous beetle Dolichus halensis (Schaller) showed a relatively low levels. The 137Cs concentrations of the necrophagous beetle Eusilpha japonica (Motshulsky) and coprophagous beetle Onthophagus lenzii (Harold) remained constant without reduction from 2013 to 2016. Average 134+137Cs concentrations throughout four years were the highest in the geophagous crustacean (Armadillidium vulgare Latreille), followed by necrophagous beetle and coprophagus beetle. The 134+137Cs concentrations in earthworms with gut contents were significantly correlated with those in soils at each habitat from 2014 to 2015 at a14-km point, and the concentration levels at an 11-km point in 2015 were remarkably high (898 kBq kg-1). Transfer factors (TFs) in earthworms ranged from 1.02 to 2.66 at a 14-km point and 0.66 to 5.0 at an11-km point. The transfer and chronological changes of radiocesium in invertebrates were discussed in relation to food habits through trophic levels in woodlands and pasturelands.
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Affiliation(s)
- Mitsuhiro Iwasa
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
| | - Fumiya Nakaya
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
| | - Hideyuki Kabeya
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
| | - Kosuke Sato
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
| | - Shin-Ichiro Ishikawa
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
| | - Teppei Takahashi
- Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
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Nemoto Y, Oomachi H, Saito R, Kumada R, Sasaki M, Takatsuki S. Effects of 137Cs contamination after the TEPCO Fukushima Dai-ichi Nuclear Power Station accident on food and habitat of wild boar in Fukushima Prefecture. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 225:106342. [PMID: 32949874 DOI: 10.1016/j.jenvrad.2020.106342] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 06/02/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
After the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, wild boar was found to have greater radiocesium (137Cs) activity concentrations in their bodies than other wild animals in Japan; however, the reason for this remains unknown. To understand the mechanism of 137Cs transfer from the environment to wild boar, and the factors that affect variation in 137Cs contamination in wild boar, we sampled muscle and stomach contents from wild boar captured in Fukushima Prefecture and analyzed the relationships among 137Cs concentrations in muscle tissue and in the stomach contents, 137Cs ground deposition at capture sites, and wild boar food habits. Significant positive relationships were observed among 137Cs activity concentrations in muscle and stomach contents, as well as 137Cs deposition density at capture sites. These results suggest that 137Cs is transferred from the environment to plant and animal materials consumed by wild boar, and then from these foods to the bodies of wild boar through digestion. However, no correlation was observed between 137Cs concentrations in stomach contents and the presence of any particular food item in stomachs of wild boar, including mushrooms. These findings suggest mushrooms and underground food items, which were found to affect 137Cs concentrations in wild animals in Europe, were not important contributors to high levels of 137Cs contamination in Japanese wild animals.
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Affiliation(s)
- Yui Nemoto
- Fukushima Prefectural Centre for Environmental Creation, 10-2, Fukasaku, Miharu Town, Fukushima, 963-7700, Japan; Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan.
| | - Hitoshi Oomachi
- Fukushima Prefectural Centre for Environmental Creation, 10-2, Fukasaku, Miharu Town, Fukushima, 963-7700, Japan; Fukushima Prefecture, 2-16, Sugitsumatyou, Fukushima, Fukushima, 960-8670, Japan
| | - Rie Saito
- Fukushima Prefectural Centre for Environmental Creation, 10-2, Fukasaku, Miharu Town, Fukushima, 963-7700, Japan
| | - Reiko Kumada
- Fukushima Prefectural Centre for Environmental Creation, 10-2, Fukasaku, Miharu Town, Fukushima, 963-7700, Japan
| | - Masataka Sasaki
- Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
| | - Seiki Takatsuki
- The Life Museum of Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
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Ozaki H, Inamochi R, Takahashi H, Takahashi H, Hara Y, Tokumaru T, Watai C, Gomi T, Watanabe I. Road Dust as a Significant Radiocesium Transporter from Land to River. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 79:39-48. [PMID: 32350556 DOI: 10.1007/s00244-020-00738-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 04/21/2020] [Indexed: 06/11/2023]
Abstract
This study made it clear that road dust plays an important role for Cs-137 dynamics emitted by the Fukushima Daiichi nuclear power plant accident. It was proved from the Cs-137 and heavy metals determination in road dust, drainage gutter sediment beside pavement, and riverbed sediment around the inflow point of the gutter. Road dust and drainage gutter sediment contained significantly higher concentrations of Cs-137 and Cr, Ni, Cu, Zn, Mo, Cd, Sn, Sb, and Pb than riverbed sediment. These heavy metals are typically enriched in road dust in general and originate in anthropogenic sources. Concentrations of Cs-137 and the heavy metals were higher in riverbed sediments at the inflow point of drainage than in non-inflow points. Drainage gutter sediments exhibited Cs-137 and heavy metal accumulation at the downmost of the gutter, which is the inflow point into the river. Accordingly, distribution of Cs-137 and the heavy metals concentrations were consistent with each other. Moreover, the concentrations of Cs-137 and heavy metals were correlated positively and significantly, with different proportions between sampling sites but similar between sample type and survey date. This indicates that the discharge of Cs-137 and heavy metals is characteristic of the features of the locations, such as Cs-137 and heavy metals concentrations, (micro-) topography, structure of the road and gutter, pavement area, traffic density, and so on. We conclude that road dust is a major medium of Cs-137 transport from land into aquatic ecosystems.
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Affiliation(s)
- Hirokazu Ozaki
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
- Fukushima Branch, National Institute for Environmental Studies, Japan, 10-2 Fukasaku, Miharu, Tamura District, Fukushima, 963-7700, Japan.
| | - Riko Inamochi
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Hiroyuki Takahashi
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Hikaru Takahashi
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Yuta Hara
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Takashi Tokumaru
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Chie Watai
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Takashi Gomi
- Department of International Environmental and Agricultural Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Izumi Watanabe
- Department of Environmental Science on Biosphere, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
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Babić D, Skoko B, Franić Z, Senčar J, Šoštarić M, Petroci L, Avdić M, Kovačić M, Branica G, Petrinec B, Bituh T, Franulović I, Marović G. Baseline radioecological data for the soil and selected bioindicator organisms in the temperate forest of Plitvice Lakes National Park, Croatia. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:21040-21056. [PMID: 32266621 DOI: 10.1007/s11356-020-08369-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study was to provide baseline radioecological data for the temperate forest ecosystem in Plitvice Lakes National Park. Emphasis was placed on the determination of naturally occurring radionuclides since there is an acknowledged lack of data for these radionuclides in non-accident conditions in wildlife, even for bioindicator organisms. Activity concentrations of 238U, 226Ra, 210Pb, 232Th, 40K, 134Cs, and 137Cs were measured by gamma spectrometry in soil and bioindicators: earthworms, conifer needles, mosses, and lichens. From the measured activity concentrations, concentration ratios were calculated to quantify the transfer of these radionuclides from soil to bioindicators. Our results show that soil activity concentrations are biased toward results from other studies conducted within the Dinaric mountain region. However, in moss and lichen samples, we measured higher activity concentrations of 226Ra and lower activity concentrations of 40K and 137Cs in comparison to similar studies. Also, we estimated lower concentration ratios for all radionuclides from soil to these organisms, except for 210Pb, in comparison to generic values. The transfer of 238U was generally low for all of the bioindicator organisms. For conifer needles, a correlation was found between activity concentrations of 226Ra and 137Cs in soil and related concentration ratios. Correlation was also found between the activity concentration of 40K in soil and transfer of 40K and 137Cs to mosses and lichens. A comparison with literature data highlighted the lack of 226Ra related concentration ratios for conifer trees and especially for earthworms. Therefore, the results of this study could supplement the sparse data currently available on radionuclide background data in similar ecosystems and related soil-to-wildlife transfer of radionuclides. Dose rate assessments, performed by the ERICA Tool, estimated that 96% of the overall exposure of wildlife in the Park area is due to the background dose rates, while 0.06 μGy h-1 on average can be attributed as an incremental dose rate from 134Cs and 137Cs.
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Affiliation(s)
- Dinko Babić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Božena Skoko
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia.
| | - Zdenko Franić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Jasminka Senčar
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Marko Šoštarić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Ljerka Petroci
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Mak Avdić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Milica Kovačić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Gina Branica
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Branko Petrinec
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Tomislav Bituh
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Iva Franulović
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
| | - Gordana Marović
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, HR-10000, Zagreb, Croatia
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Ayabe Y, Yoshida T, Kanasashi T, Hayashi A, Fukushi A, Hijii N, Takenaka C. Web-building spider Nephila clavata (Nephilidae: Arachnida) can represent 137Cs contamination of arthropod communities and bioavailable 137Cs in forest soils at Fukushima, Japan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:1176-1185. [PMID: 31412453 DOI: 10.1016/j.scitotenv.2019.06.158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/22/2019] [Accepted: 06/10/2019] [Indexed: 06/10/2023]
Abstract
Large areas of Fukushima's forests were contaminated with radiocesium (137Cs) after the Fukushima Dai-ichi Nuclear Power Plant accident. Most of the contaminated forests have not been decontaminated, and bioavailable 137Cs is likely to circulate within the forest environment's food web. Nephila clavata (Nephilidae: Arachnida) is a top predator in the forest arthropod community, and this web-building spider potentially consumes many arthropod species presented in the grazing and detrital food chains. We tested whether 137Cs in the spider could serve as a proxy for 137Cs contamination of these arthropod communities. We also examined whether N. clavata could serve as a proxy for soil bioavailable 137Cs. Nephila clavata was similarly or more contaminated with 137Cs compared with lower-trophic-level arthropods such as herbivores and other predators at the same trophic level. Thus, the 137Cs activity of N. clavata could represent the extent to which the arthropod community was contaminated with 137Cs. Data from nine 137Cs-contaminated sites in Fukushima showed a significant positive correlation between soil bioavailable 137Cs and N. clavata's 137Cs activity05 but the coefficient of determination was only moderate (R2 = 0.43), suggesting that N. clavata is only a weak proxy of soil bioavailable 137Cs. Our results also showed that the bioavailable fraction of 137Cs in Fukushima was strongly correlated with the total inventory and that the K and Na contents of the soil determined the soil-to-spider transfer factor for 137Cs and the 137Cs activity in N. clavata, respectively. These results improve our understanding of 137Cs transfer from the soil to arthropod species.
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Affiliation(s)
- Yoshiko Ayabe
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
| | - Tomohiro Yoshida
- Field Science Center, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
| | - Tsutomu Kanasashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
| | - Akane Hayashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Akihisa Fukushi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Naoki Hijii
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
| | - Chisato Takenaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
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Tanaka S, Adati T, Takahashi T, Fujiwara K, Takahashi S. Concentrations and biological half-life of radioactive cesium in epigeic earthworms after the Fukushima Dai-ichi Nuclear Power Plant accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 192:227-232. [PMID: 29986314 DOI: 10.1016/j.jenvrad.2018.06.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/08/2018] [Accepted: 06/26/2018] [Indexed: 06/08/2023]
Abstract
To understand the long-term behavior of radiocesium in the biological processes of a forest ecosystem, its concentration in Japanese epigeic earthworms (Megascolecidae), litter, and soil, and the ambient dose equivalent rates, were investigated after the Fukushima Dai-ichi Nuclear Power Plant accident. The metabolism of radiocesium in the earthworms was also investigated in the laboratory, and its biological half-life (Tb) was estimated. The concentration of 137Cs in the habitat soil and litter changed from 2014 to 2016, with levels in the litter going from 44.9 Bq/g dw (in 2014) to 45.3 Bq/g dw (2015) and 10.7 Bq/g dw (2016); in soil, these values were 9.79 Bq/g dw, 7.14 Bq/g dw and 18.0 Bq/g dw, respectively. By contrast, no significant changes were observed in the concentrations in the earthworms, which were 4.87 Bq/g fw, 5.30 Bq/g fw and 4.67 Bq/g fw in 2014, 2015, and 2016, respectively. The ambient dose equivalent rates at the sampling site declined significantly over these three years, going from 2.15 μSv/h to 1.68 μSv/h and 1.35 μSv/h, mostly corresponding to physical decay of radiocesium. The majority (95%) of the 137Cs in the earthworms, observed via autoradiography, was concentrated primarily in the intestine. The clearance of 137Cs from the earthworms was described by dual exponential functions: the half-life in the rapid loss due to gut clearance was 0.10 days and a second slower loss due to physiological clearance was 27.4 days.
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Affiliation(s)
- S Tanaka
- Kyoto University Graduate School of Agriculture, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
| | - T Adati
- Department of International Agricultural Development, Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Sakuragaoka, Setagaya, 156-8502 Tokyo, Japan
| | - T Takahashi
- Kyoto University Graduate School of Agriculture, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan; Division of Radiation Safety and Control, The Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - K Fujiwara
- Technical Staff Office, The Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - S Takahashi
- Division of Radiation Safety and Control, The Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
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Negishi JN, Sakai M, Okada K, Iwamoto A, Gomi T, Miura K, Nunokawa M, Ohhira M. Cesium-137 contamination of river food webs in a gradient of initial fallout deposition in Fukushima, Japan. LANDSCAPE AND ECOLOGICAL ENGINEERING 2017. [DOI: 10.1007/s11355-017-0328-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Fuma S, Ihara S, Takahashi H, Inaba O, Sato Y, Kubota Y, Watanabe Y, Kawaguchi I, Aono T, Soeda H, Yoshida S. Radiocaesium contamination and dose rate estimation of terrestrial and freshwater wildlife in the exclusion zone of the Fukushima Dai-ichi Nuclear Power Plant accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 171:176-188. [PMID: 28262604 DOI: 10.1016/j.jenvrad.2017.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/07/2016] [Accepted: 02/15/2017] [Indexed: 06/06/2023]
Abstract
To characterise the radioactive contamination of terrestrial and freshwater wildlife caused by the Fukushima Dai-ichi Nuclear Power Plant accident, biological samples, namely, fungi, mosses, plants, amphibians, reptiles, insects, molluscs, and earthworms, were collected mainly from the forests of the exclusion zone in the Fukushima Prefecture from 2011 to 2012. Caesium-134 and 137Cs were detected by gamma spectrometry in almost all the samples. Fungi, ferns, and mosses accumulated high amounts of radiocaesium, as they did in Chernobyl, with 134Cs + 137Cs activity concentrations of 104-106 Bq kg-1 fresh mass (FM). Earthworms, amphibians, and the soft tissue of the garden snail Acusta despecta sieboldiana, also had levels as high as 104-105 Bq kg-1 FM of 134Cs + 137Cs. Most of the estimated total (internal + external) dose rates to herbaceous plants, amphibians, insects, and earthworms were below the corresponding derived consideration reference levels (DCRLs) recommended by the ICRP. This suggests that, in most cases, there was little chance of deleterious effects of ionising radiation on these organisms in the exclusion zone for the first year after the accident, though the dose rates were underestimated mainly due to the lack of consideration of short-lived radionuclides.
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Affiliation(s)
- Shoichi Fuma
- Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
| | - Sadao Ihara
- Hokkaido University of Education Kushiro Campus, 1-15-55 Shiroyama, Kushiro, Hokkaido, 085-8580, Japan
| | - Hiroyuki Takahashi
- Tokyo Nuclear Services Co., Ltd., Sorimachi Building, 1-3-5 Taito, Taito-ku, Tokyo, 110-0016, Japan
| | - Osamu Inaba
- Minamisoma City Museum, 194 Deguchi, Gorai, Haramachi-ku, Minamisoma, Fukushima, 975-0051, Japan
| | | | - Yoshihisa Kubota
- Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Yoshito Watanabe
- Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Isao Kawaguchi
- Center for Radiation Protection Knowledge, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Tatsuo Aono
- Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Haruhi Soeda
- Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Satoshi Yoshida
- Department of Management and Planning, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
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11
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Strand P, Sundell-Bergman S, Brown JE, Dowdall M. On the divergences in assessment of environmental impacts from ionising radiation following the Fukushima accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 169-170:159-173. [PMID: 28119209 DOI: 10.1016/j.jenvrad.2016.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 06/06/2023]
Abstract
The accident at the Fukushima-Daiichi Nuclear Power Station on March 11, 2011, led to significant contamination of the surrounding terrestrial and marine environments. Whilst impacts on human health remain the primary concern in the aftermath of such an accident, recent years have seen a significant body of work conducted on the assessment of the accident's impacts on both the terrestrial and marine environment. Such assessments have been undertaken at various levels of biological organisation, for different species, using different methodologies and coming, in many cases, to divergent conclusions as to the effects of the accident on the environment. This article provides an overview of the work conducted in relation to the environmental impacts of the Fukushima accident, critically comparing and contrasting methodologies and results with a view towards finding reasons for discrepancies, should they indeed exist. Based on the outcomes of studies conducted to date, it would appear that in order to avoid the fractured and disparate conclusions drawn in the aftermath of previous accidents, radioactive contaminants and their effects can no longer simply be viewed in isolation with respect to the ecosystems these effects may impact. A combination of laboratory based and field studies with a focus on ecosystem functioning and effects could offer the best opportunities for coherence in the interpretation of the results of studies into the environmental impacts of ionising radiation.
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Affiliation(s)
- P Strand
- CERAD, Norwegian University of Life Sciences, 1430 Ås, Norway.
| | - S Sundell-Bergman
- Department of Soil and Environment, Swedish University of Agricultural Sciences (SLU), Box 7014, 750 07 Uppsala, Sweden
| | - J E Brown
- Norwegian Radiation Protection Authority, Grini næringspark 13, 1332 Østerås, Norway
| | - M Dowdall
- Norwegian Radiation Protection Authority, Grini næringspark 13, 1332 Østerås, Norway
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12
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Ishii Y, Hayashi S, Takamura N. Radiocesium Transfer in Forest Insect Communities after the Fukushima Dai-ichi Nuclear Power Plant Accident. PLoS One 2017; 12:e0171133. [PMID: 28125745 PMCID: PMC5268780 DOI: 10.1371/journal.pone.0171133] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/16/2017] [Indexed: 11/18/2022] Open
Abstract
To understand radiocesium transfer in the forest insect food web, we investigated the activity concentrations of radiocesium in forest insects in the Fukushima and Ibaraki Prefectures approximately 1.5–2.5 years after the Fukushima Dai-ichi Nuclear Power Plant. We analyzed 34 species of insects sampled from 4 orders and 4 feeding functional groups (herbivore, carnivore, omnivore, and detritivore) from three sites in each prefecture. 137Cs activity concentrations were lowest in herbivorous species and were especially high in detritivorous and omnivorous species that feed on forest litter and fungi. Radiocesium activity concentrations in any given species reflected the degree of contamination of that species’ primary food sources since radiocesium activity concentrations were found to be the lowest in leaves and grass and the highest in litter, bark, and fungi. This study confirmed that litter and other highly contaminated forest components such as fungi, decaying wood, bryophytes, and lichens serve as sources of 137Cs transfer into the forest insect community.
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Affiliation(s)
- Yumiko Ishii
- Environmental Impact Assessment Section, Fukushima Branch, National Institute for Environmental Studies, Miharu Town, Tamura County, Fukushima, Japan
- * E-mail:
| | - Seiji Hayashi
- Environmental Impact Assessment Section, Fukushima Branch, National Institute for Environmental Studies, Miharu Town, Tamura County, Fukushima, Japan
| | - Noriko Takamura
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
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13
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Sakai M, Gomi T, Negishi JN. Fallout volume and litter type affect 137Cs concentration difference in litter between forest and stream environments. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2016; 164:169-173. [PMID: 27479036 DOI: 10.1016/j.jenvrad.2016.07.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/19/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
It is important to understand the changes in the 137Cs concentration in litter through leaching when considering that 137Cs is transferred from basal food resources to animals in forested streams. We found that the difference of 137Cs activity concentration in litter between forest and stream was associated with both litter type and 137Cs fallout volume around Fukushima, Japan. The 137Cs activity concentrations in the litter of evergreen conifers tended to be greater than those in the litter of broad-leaved deciduous trees because of the absence of deciduous leaves during the fallout period in March 2011. Moreover, 137Cs activity concentrations in forest litter were greater with respect to the 137Cs fallout volume. The 137Cs activity concentrations in stream litter were much lower than those in forest litter when those in forest litter were higher. The 137Cs leaching patterns indicated that the differences in 137Cs activity concentration between forest and stream litter could change with changes in both fallout volume and litter type. Because litter is an important basal food resource in the food webs of both forests and streams, the 137Cs concentration gradient reflects to possible 137Cs transfer from lower to higher trophic animals. Our findings will improve our understanding of the spatial heterogeneity and variability of 137Cs concentrations in animals resident to the contaminated landscape.
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Affiliation(s)
- Masaru Sakai
- Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
| | - Takashi Gomi
- Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
| | - Junjiro N Negishi
- Faculty of Environmental Earth Science, Hokkaido University, N10, W5, Kita-ku, Sapporo, Hokkaido, 060-0860, Japan.
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14
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Hayashi C, Nakamura K, Hongo T, Hashimoto H, Harada R, Nakanishi K, Ishii T. Surveillance of Radioactive Cesium in Meats of Wild Animals Caught in Chiba Prefecture. Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) 2016; 57:32-6. [PMID: 27211916 DOI: 10.3358/shokueishi.57.32] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
From fiscal year 2012 to 2014, we surveyed the concentration of radioactive cesium in 39 wild animal meats obtained from 20 wild boars and 19 deer caught in Chiba prefecture, using a germanium semiconductor detector. Four wild boar meats in the fiscal years 2012 and 2013 exceeded the radioactive cesium limit in general foods (100 Bq/kg), whereas none of the deer meats exceeded the limit. The left side of the wild boar that showed a radioactive cesium concentration above 100 Bq/kg was divided into 14 parts. We compared the radioactive cesium concentration in the ham used for the screening test with those in other parts. The concentration was highest in ham, among the edible parts.
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15
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Okano T, Ishiniwa H, Onuma M, Shindo J, Yokohata Y, Tamaoki M. Effects of environmental radiation on testes and spermatogenesis in wild large Japanese field mice (Apodemus speciosus) from Fukushima. Sci Rep 2016; 6:23601. [PMID: 27005329 PMCID: PMC4804236 DOI: 10.1038/srep23601] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/10/2016] [Indexed: 02/08/2023] Open
Abstract
The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred after the Great East Japan Earthquake in March 2011 released large quantities of radionuclides to the environment. The long-term effects of radioactive cesium (Cs) on biota are of particular concern. We investigated the accumulation of radioactive Cs derived from the FDNPP accident, and chronic effects of environmental radionuclides on male reproduction, in the large Japanese field mouse (Apodemus speciosus). In 2013 and 2014, wild mice were captured at 2 sites in Fukushima Prefecture and at 2 control sites that were distant from Fukushima. Although the median concentrations of (134)Cs and (137)Cs in the mice from Fukushima exceeded 4,000 Bq/kg, there were no significant differences in the apoptotic cell frequencies or the frequencies of morphologically abnormal sperm among the capture sites. Thus, we conclude that radiation did not cause substantial male subfertility in Fukushima during 2013 and 2014, and radionuclide pollution levels in the study sites would not be detrimental to spermatogenesis of the wild mice in Fukushima.
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Affiliation(s)
- Tsukasa Okano
- Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Hiroko Ishiniwa
- Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Manabu Onuma
- Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Junji Shindo
- Laboratory of Wildlife Science, School of Veterinary Medicine, Kitasato University, Higashi 23-35-1, Towada, Aomori 034-8628, Japan
| | - Yasushi Yokohata
- Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama, Toyama 930-8555, Japan
| | - Masanori Tamaoki
- Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
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16
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Sakai M, Gomi T, Negishi JN, Iwamoto A, Okada K. Different cesium-137 transfers to forest and stream ecosystems. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 209:46-52. [PMID: 26629645 DOI: 10.1016/j.envpol.2015.11.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 11/14/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
Understanding the mechanisms of (137)Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of (137)Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of (137)Cs in stream litter was significantly lower than in forest litter, the result of (137)Cs leaching from litter in stream water. The difference in (137)Cs concentrations between the two types of litter was reflected in the (137)Cs concentrations in the animal community. While the importance of (137)Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of (137)Cs through terrestrial and aquatic ecosystems, and that (137)Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem.
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Affiliation(s)
- Masaru Sakai
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Takashi Gomi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Junjiro N Negishi
- Faculty of Environmental Earth Science, Hokkaido University, N10, W5, Kita-ku, Sapporo, Hokkaido 060-0860, Japan.
| | - Aimu Iwamoto
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Kengo Okada
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
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17
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Evrard O, Laceby JP, Lepage H, Onda Y, Cerdan O, Ayrault S. Radiocesium transfer from hillslopes to the Pacific Ocean after the Fukushima Nuclear Power Plant accident: A review. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 148:92-110. [PMID: 26142817 DOI: 10.1016/j.jenvrad.2015.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/11/2015] [Accepted: 06/22/2015] [Indexed: 06/04/2023]
Abstract
The devastating tsunami triggered by the Great East Japan Earthquake on March 11, 2011 inundated the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) resulting in a loss of cooling and a series of explosions releasing the largest quantity of radioactive material into the atmosphere since the Chernobyl nuclear accident. Although 80% of the radionuclides from this accidental release were transported over the Pacific Ocean, 20% were deposited over Japanese coastal catchments that are subject to frequent typhoons. Among the radioisotopes released during the FDNPP accident, radiocesium ((134)Cs and (137)Cs) is considered the most serious current and future health risk for the local population. The goal of this review is to synthesize research relevant to the transfer of FDNPP derived radiocesium from hillslopes to the Pacific Ocean. After radiocesium fallout deposition on vegetation and soils, the contamination may remain stored in forest canopies, in vegetative litter on the ground, or in the soil. Once radiocesium contacts soil, it is quickly and almost irreversibly bound to fine soil particles. The kinetic energy of raindrops instigates the displacement of soil particles, and their bound radiocesium, which may be mobilized and transported with overland flow. Soil erosion is one of the main processes transferring particle-bound radiocesium from hillslopes through rivers and streams, and ultimately to the Pacific Ocean. Accordingly this review will summarize results regarding the fundamental processes and dynamics that govern radiocesium transfer from hillslopes to the Pacific Ocean published in the literature within the first four years after the FDNPP accident. The majority of radiocesium is reported to be transported in the particulate fraction, attached to fine particles. The contribution of the dissolved fraction to radiocesium migration is only relevant in base flows and is hypothesized to decline over time. Owing to the hydro-meteorological context of the Fukushima region, the most significant transfer of particulate-bound radiocesium occurs during major rainfall and runoff events (e.g. typhoons and spring snowmelt). There may be radiocesium storage within catchments in forests, floodplains and even within hillslopes that may be remobilized and contaminate downstream areas, even areas that did not receive fallout or may have been decontaminated. Overall this review demonstrates that characterizing the different mechanisms and factors driving radiocesium transfer is important. In particular, the review determined that quantifying the remaining catchment radiocesium inventory allows for a relative comparison of radiocesium transfer research from hillslope to catchment scales. Further, owing to the variety of mechanisms and factors, a transdisciplinary approach is required involving geomorphologists, hydrologists, soil and forestry scientists, and mathematical modellers to comprehensively quantify radiocesium transfers and dynamics. Characterizing radiocesium transfers from hillslopes to the Pacific Ocean is necessary for ongoing decontamination and management interventions with the objective of reducing the gamma radiation exposure to the local population.
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Affiliation(s)
- Olivier Evrard
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France.
| | - J Patrick Laceby
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
| | - Hugo Lepage
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
| | - Yuichi Onda
- Graduate School of Life and Environmental Sciences, Center for Research in Isotopes and Environmental Dynamics (CRIED), University of Tsukuba, Tsukuba, Japan
| | - Olivier Cerdan
- Bureau de Recherches Géologiques et Minières, Orléans, France
| | - Sophie Ayrault
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France
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18
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Hasegawa M, Kaneko S, Ikeda S, Akama A, Komatsu M, Ito MT. Changes in radiocesium concentrations in epigeic earthworms in relation to the organic layer 2.5 years after the 2011 Fukushima Dai-ichi Nuclear Power Plant accident. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 145:95-101. [PMID: 25890129 DOI: 10.1016/j.jenvrad.2015.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 03/02/2015] [Accepted: 03/12/2015] [Indexed: 06/04/2023]
Abstract
We reported previously that radiocesium ((137)Cs) concentrations in earthworms increased with those in litter and/or soil in Fukushima Prefecture forests 0.5 y after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. This study provides further results for 1.5 and 2.5 y after the accident and discusses temporal changes in (137)Cs concentrations and transfer factors (TF) from litter to earthworms to better understand the mechanisms by which (137)Cs enters soil food webs. The concentration of (137)Cs in accumulated litter on the forest floor rapidly decreased, and the concentration in soil (0-5-cm depth) increased over time from 0.5 to 1.5 y, but changed only moderately from 1.5 to 2.5 y. The concentration of (137)Cs in earthworms consistently decreased during the study period; values 2.5 y after the accident were 18.8-68.5% of those 0.5 y after the accident. The TFs from accumulated litter to earthworms decreased over time: 0.24 ± 0.08 (mean ± SD) at 0.5 y and 0.16 ± 0.04 at 2.5 y. This decrease may be a result of decreases in the bioavailability of (137)Cs in litter and the surface soil layer. Changes in (137)Cs bioavailability should be continuously tracked to determine any changes in the relationship between radiocesium concentrations in earthworms and that in accumulated litter or soil.
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Affiliation(s)
- Motohiro Hasegawa
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
| | - Shinji Kaneko
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
| | - Shigeto Ikeda
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
| | - Akio Akama
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
| | - Masabumi Komatsu
- Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan.
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Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster. Sci Rep 2015; 5:9712. [PMID: 25857262 PMCID: PMC4392359 DOI: 10.1038/srep09712] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/11/2015] [Indexed: 11/08/2022] Open
Abstract
We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations ((134)Cs and (137)Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.
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Takahara T, Endo S, Takada M, Oba Y, Nursal WI, Igawa T, Doi H, Yamada T, Okuda T. Radiocesium accumulation in the anuran frog, Rana tagoi tagoi, in forest ecosystems after the Fukushima Nuclear Power Plant accident. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 199:89-94. [PMID: 25638689 DOI: 10.1016/j.envpol.2015.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/23/2015] [Accepted: 01/24/2015] [Indexed: 06/04/2023]
Abstract
Amphibians are key components in forest food webs. When examining radioactive contamination in anurans, it is important to understand how radiocesium transfer occurs from lower to higher trophic levels in forest ecosystems. We investigated the activity concentration of radiocesium ((134)Cs and (137)Cs) in Tago's brown frog (Rana tagoi tagoi) captured on the forest floor approximately 2.5 years after the Fukushima Nuclear Power Plant (FNPP) accident. We collected 66 R. tagoi tagoi at different distances from the FNPP. Radiocesium accumulation showed positive correlations with the air radiation dose rate and litter contamination but not with distance from the FNPP. Whole-body radioactivity showed no correlation with body mass or length. Our results suggest that differences in the available food items result in large variability in individual contamination. Contamination level monitoring in terrestrial and aquatic amphibian is necessary for clarifying the processes and mechanisms of radiocesium transfer through forest food webs.
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Affiliation(s)
- Teruhiko Takahara
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan.
| | - Satoru Endo
- Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
| | - Momo Takada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
| | - Yurika Oba
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
| | - Wim Ikbal Nursal
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
| | - Takeshi Igawa
- Graduate School of International Development and Cooperation, Hiroshima University, 1-5-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8529, Japan
| | - Hideyuki Doi
- Institute for Sustainable Sciences and Development, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Toshihiro Yamada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
| | - Toshinori Okuda
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
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21
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Sohtome T, Wada T, Mizuno T, Nemoto Y, Igarashi S, Nishimune A, Aono T, Ito Y, Kanda J, Ishimaru T. Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2014; 138:106-115. [PMID: 25216467 DOI: 10.1016/j.jenvrad.2014.08.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/04/2014] [Accepted: 08/19/2014] [Indexed: 06/03/2023]
Abstract
Radioactive cesium ((134)Cs and (137)Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3-500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher (137)Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of (137)Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall (137)Cs concentrations in invertebrates, the maxima of which (290 Bq kg(-1)-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of (137)Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta.
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Affiliation(s)
- Tadahiro Sohtome
- Fukushima Prefectural Fisheries Experimental Station, Iwaki, Fukushima 9700316, Japan
| | - Toshihiro Wada
- Soma Branch, Fukushima Prefectural Fisheries Experimental Station, Soma, Fukushima 9760022, Japan.
| | - Takuji Mizuno
- Fukushima Prefectural Fisheries Experimental Station, Iwaki, Fukushima 9700316, Japan
| | - Yoshiharu Nemoto
- Fisheries Office of Fukushima Prefectural Government, Iwaki, Fukushima 9708026, Japan
| | - Satoshi Igarashi
- Fukushima Prefectural Fisheries Experimental Station, Iwaki, Fukushima 9700316, Japan
| | - Atsushi Nishimune
- University of Fukui, Faculty of Medical Sciences, Yoshida-gun, Fukui 9101193, Japan
| | - Tatsuo Aono
- National Institute of Radiological Sciences, Chiba, Chiba 2638555, Japan
| | - Yukari Ito
- Tokyo University of Marine Science and Technology, Minato-ku, Tokyo 1088477, Japan
| | - Jota Kanda
- Tokyo University of Marine Science and Technology, Minato-ku, Tokyo 1088477, Japan
| | - Takashi Ishimaru
- Tokyo University of Marine Science and Technology, Minato-ku, Tokyo 1088477, Japan
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22
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Background internal dose rates of earthworm and arthropod species in the forests of Aomori, Japan. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3498-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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