1
|
Sakauchi K, Otaki JM. Soil Microbes and Plant-Associated Microbes in Response to Radioactive Pollution May Indirectly Affect Plants and Insect Herbivores: Evidence for Indirect Field Effects from Chernobyl and Fukushima. Microorganisms 2024; 12:364. [PMID: 38399767 PMCID: PMC10892324 DOI: 10.3390/microorganisms12020364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
The biological impacts of the nuclear accidents in Chernobyl (1986) and Fukushima (2011) on wildlife have been studied in many organisms over decades, mainly from dosimetric perspectives based on laboratory experiments using indicator species. However, ecological perspectives are required to understand indirect field-specific effects among species, which are difficult to evaluate under dosimetric laboratory conditions. From the viewpoint that microbes play a fundamental role in ecosystem function as decomposers and symbionts for plants, we reviewed studies on microbes inhabiting soil and plants in Chernobyl and Fukushima in an attempt to find supporting evidence for indirect field-specific effects on plants and insect herbivores. Compositional changes in soil microbes associated with decreases in abundance and species diversity were reported, especially in heavily contaminated areas of both Chernobyl and Fukushima, which may accompany explosions of radioresistant species. In Chernobyl, the population size of soil microbes remained low for at least 20 years after the accident, and the abundance of plant-associated microbes, which are related to the growth and defense systems of plants, possibly decreased. These reported changes in microbes likely affect soil conditions and alter plant physiology. These microbe-mediated effects may then indirectly affect insect herbivores through food-mass-mediated, pollen-mediated, and metabolite-mediated interactions. Metabolite-mediated interactions may be a major pathway for ecological impacts at low pollution levels and could explain the decreases in insect herbivores in Fukushima. The present review highlights the importance of the indirect field effects of long-term low-dose radiation exposure under complex field circumstances.
Collapse
Affiliation(s)
| | - Joji M. Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara 903-0213, Okinawa, Japan;
| |
Collapse
|
2
|
Sakauchi K, Otaki JM. Imaging Plate Autoradiography for Ingested Anthropogenic Cesium-137 in Butterfly Bodies: Implications for the Biological Impacts of the Fukushima Nuclear Accident. Life (Basel) 2023; 13:life13051211. [PMID: 37240856 DOI: 10.3390/life13051211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The Fukushima nuclear accident in March 2011 caused biological impacts on the pale grass blue butterfly Zizeeria maha. At least some of the impacts are likely mediated by the host plant, resulting in "field effects". However, to obtain the whole picture of the impacts, direct exposure effects should also be evaluated. Here, we examined the distribution of experimentally ingested anthropogenic cesium-137 (137Cs) in adult butterfly bodies using imaging plate autoradiography. We showed that 137Cs ingested by larvae was incorporated into adult bodies and was biased to females, although the majority of ingested 137Cs was excreted in the pupal cuticle and excretory material during eclosion. 137Cs accumulation in adult bodies was the highest in the abdomen, followed by the thorax and other organs. These results suggest that 137Cs accumulation in reproductive organs may cause adverse transgenerational or maternal effects mediated by reactive oxygen species (ROS) on germ cells. 137Cs accumulation was detected in field individuals collected in September 2011 and September 2016 but not in May 2011, which is consistent with the abnormality dynamics known from previous studies. Taken together, these results contribute to an integrative understanding of the multifaceted biological effects of the Fukushima nuclear accident in the field.
Collapse
Affiliation(s)
- Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara 903-0213, Okinawa, Japan
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara 903-0213, Okinawa, Japan
| |
Collapse
|
3
|
Otaki JM, Sakauchi K, Taira W. The second decade of the blue butterfly in Fukushima: Untangling the ecological field effects after the Fukushima nuclear accident. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2022; 18:1539-1550. [PMID: 35475314 DOI: 10.1002/ieam.4624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 02/24/2022] [Accepted: 04/24/2022] [Indexed: 06/14/2023]
Abstract
Many field observations of the biological effects of the Fukushima nuclear accident have been reported in the first decade after the accident. A series of observational and experimental studies have demonstrated causal adverse effects on the pale grass blue butterfly even at the low-level radiation exposure in the "field," contrary to the dosimetric view that insects are generally tolerant of radiation exposure. However, it has been demonstrated that the pale grass blue butterfly is tolerant of high oral doses of anthropogenic radioactive cesium (137 Cs) under "laboratory" conditions. This field-laboratory paradox can be explained by ecological field effects; for example, radiation stress in the field causes physiological and biochemical changes in the host plant, which then trophically affects butterfly larvae. The second decade of butterfly-based Fukushima research will be devoted to demonstrating how such adverse field effects occur. Changes in the host plant's nutritional contents likely affect butterfly physiology. The host plant may also upregulate secondary metabolites that affect herbivorous insects. The plant may be affected by changes in endophytic soil microbes in radioactively contaminated areas. If demonstrated, these results will reveal that the delicate ecological balances among the butterfly, its host plant, and soil microbes have been affected by radioactive pollution in Fukushima, which has important implications for environmental policies and human health. Integr Environ Assess Manag 2022;18:1539-1550. © SETAC.
Collapse
Affiliation(s)
- Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, Japan
- Research Planning Office, University of the Ryukyus, Okinawa, Japan
| |
Collapse
|
4
|
Ingestional Toxicity of Radiation-Dependent Metabolites of the Host Plant for the Pale Grass Blue Butterfly: A Mechanism of Field Effects of Radioactive Pollution in Fukushima. Life (Basel) 2022; 12:life12050615. [PMID: 35629283 PMCID: PMC9146399 DOI: 10.3390/life12050615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 12/17/2022] Open
Abstract
Biological effects of the Fukushima nuclear accident have been reported in various organisms, including the pale grass blue butterfly Zizeeria maha and its host plant Oxalis corniculata. This plant upregulates various secondary metabolites in response to low-dose radiation exposure, which may contribute to the high mortality and abnormality rates of the butterfly in Fukushima. However, this field effect hypothesis has not been experimentally tested. Here, using an artificial diet for larvae, we examined the ingestional toxicity of three radiation-dependent plant metabolites annotated in a previous metabolomic study: lauric acid (a saturated fatty acid), alfuzosin (an adrenergic receptor antagonist), and ikarugamycin (an antibiotic likely from endophytic bacteria). Ingestion of lauric acid or alfuzosin caused a significant decrease in the pupation, eclosion (survival), and normality rates, indicating toxicity of these compounds. Lauric acid made the egg-larval days significantly longer, indicating larval growth retardation. In contrast, ikarugamycin caused a significant increase in the pupation and eclosion rates, probably due to the protection of the diet from fungi and bacteria. These results suggest that at least some of the radiation-dependent plant metabolites, such as lauric acid, contribute to the deleterious effects of radioactive pollution on the butterfly in Fukushima, providing experimental evidence for the field effect hypothesis.
Collapse
|
5
|
Sakauchi K, Taira W, Otaki JM. Metabolomic Profiles of the Creeping Wood Sorrel Oxalis corniculata in Radioactively Contaminated Fields in Fukushima: Dose-Dependent Changes in Key Metabolites. Life (Basel) 2022; 12:life12010115. [PMID: 35054508 PMCID: PMC8780803 DOI: 10.3390/life12010115] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/11/2022] [Accepted: 01/11/2022] [Indexed: 12/27/2022] Open
Abstract
The biological impacts of the Fukushima nuclear accident, in 2011, on wildlife have been studied in many organisms, including the pale grass blue butterfly and its host plant, the creeping wood sorrel Oxalis corniculata. Here, we performed an LC–MS-based metabolomic analysis on leaves of this plant collected in 2018 from radioactively contaminated and control localities in Fukushima, Miyagi, and Niigata prefectures, Japan. Using 7967 peaks detected by LC–MS analysis, clustering analyses showed that nine Fukushima samples and one Miyagi sample were clustered together, irrespective of radiation dose, while two Fukushima (Iitate) and two Niigata samples were not in this cluster. However, 93 peaks were significantly different (FDR < 0.05) among the three dose-dependent groups based on background, low, and high radiation dose rates. Among them, seven upregulated and 15 downregulated peaks had single annotations, and their peak intensity values were positively and negatively correlated with ground radiation dose rates, respectively. Upregulated peaks were annotated as kudinoside D (saponin), andrachcinidine (alkaloid), pyridoxal phosphate (stress-related activated vitamin B6), and four microbe-related bioactive compounds, including antibiotics. Additionally, two peaks were singularly annotated and significantly upregulated (K1R1H1; peptide) or downregulated (DHAP(10:0); decanoyl dihydroxyacetone phosphate) most at the low dose rates. Therefore, this plant likely responded to radioactive pollution in Fukushima by upregulating and downregulating key metabolites. Furthermore, plant-associated endophytic microbes may also have responded to pollution, suggesting their contributions to the stress response of the plant.
Collapse
Affiliation(s)
- Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
| | - Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
- Research Planning Office, University of the Ryukyus, Okinawa 903-0213, Japan
| | - Joji M. Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
- Correspondence: ; Tel.: +81-98-895-8557
| |
Collapse
|
6
|
Li J, Wang Y, Li W, Bhat SA, Wei Y, Deng Z, Hao X, Li F. Accumulation capability for cesium differs among bacterial species: A comprehensive study using bacteria isolated from freshwater and coastal sediment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 292:118431. [PMID: 34743968 DOI: 10.1016/j.envpol.2021.118431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/29/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
The fate and behavior of radioactive cesium (Cs) in the water environment are of great concern. The involvement of bacteria regarding their accumulation capability for this element is the most fundamental factor that needs to be clarified even for exploring the interactions between many environmental factors that involve together in governing the transport and distribution of Cs. As the first systematical study that aimed to evaluate the accumulation capability of environmental bacteria for Cs, bacteria in the sediment of a freshwater reservoir and coastal water environment were isolated and multiplied for contact experiment with Cs under different temperature conditions (5, 25, and 35 °C). The accumulation concentration of Cs in bacteria from freshwater sediment varied in 3.95 × 10-6 to 5.68 × 10-4ng-Cs/cell, and that from coastal sediment in 1.52 × 10-6 to 7.41 × 10-4ng-Cs/cell, indicating obvious differences among bacterial species. Bacteria of coastal sediment possessed higher accumulation capability for Cs than bacteria from freshwater sediment, and temperature dependency was confirmed for bacteria from coastal sediment. The findings of this study have great reference value for better understanding and controlling the fate and behavior of radioactive Cs associated with bacteria in the water environment.
Collapse
Affiliation(s)
- Jiefeng Li
- Department of Architecture, Lu Liang University, Luliang, 033001, PR China.
| | - Yajie Wang
- Department of Life Science, Lu Liang University, Luliang, 033001, PR China; Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Wenjiao Li
- Graduate School of Global Environmental Studies, Kyoto University, Sakyo-Ku, Kyoto, 606-8501, Japan
| | - Sartaj Ahmad Bhat
- Department of Environmental Sciences, Government Degree College Anantnag, Khanabal, Jammu and Kashmir, 192101, India; River Basin Research Center, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yongfen Wei
- River Basin Research Center, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Zhiyi Deng
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, PR China
| | - Xiaodi Hao
- Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing University of Civil Engineering & Architecture, Beijing, 100044, PR China
| | - Fusheng Li
- Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan; River Basin Research Center, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| |
Collapse
|
7
|
Sakauchi K, Taira W, Otaki JM. Metabolomic Response of the Creeping Wood Sorrel Oxalis corniculata to Low-Dose Radiation Exposure from Fukushima's Contaminated Soil. Life (Basel) 2021; 11:life11090990. [PMID: 34575139 PMCID: PMC8472241 DOI: 10.3390/life11090990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/15/2021] [Accepted: 09/17/2021] [Indexed: 12/25/2022] Open
Abstract
The biological consequences of the Fukushima nuclear accident have been intensively studied using the pale grass blue butterfly Zizeeria maha and its host plant, the creeping wood sorrel Oxalis corniculata. Here, we performed metabolomic analyses of Oxalis leaves from Okinawa to examine the plant metabolites that were upregulated or downregulated in response to low-dose radiation exposure from Fukushima's contaminated soil. The cumulative dose of radiation to the plants was 5.7 mGy (34 μGy/h for 7 days). The GC-MS analysis revealed a systematic tendency of downregulation among the metabolites, some of which were annotated as caproic acid, nonanoic acid, azelaic acid, and oleic acid. Others were annotated as fructose, glucose, and citric acid, involved in the carbohydrate metabolic pathways. Notably, the peak annotated as lauric acid was upregulated. In contrast, the LC-MS analysis detected many upregulated metabolites, some of which were annotated as either antioxidants or stress-related chemicals involved in defense pathways. Among them, only three metabolite peaks had a single annotation, one of which was alfuzosin, an antagonist of the α1-adrenergic receptor. We conclude that this Oxalis plant responded metabolically to low-dose radiation exposure from Fukushima's contaminated soil, which may mediate the ecological "field effects" of the developmental deterioration of butterflies in Fukushima.
Collapse
Affiliation(s)
- Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
| | - Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
- Center for Research Advancement and Collaboration, University of the Ryukyus, Okinawa 903-0213, Japan
| | - Joji M. Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan; (K.S.); (W.T.)
- Correspondence: ; Tel.: +81-98-895-8557
| |
Collapse
|
8
|
Bomb 137Cs in modern honey reveals a regional soil control on pollutant cycling by plants. Nat Commun 2021; 12:1937. [PMID: 33782399 PMCID: PMC8007572 DOI: 10.1038/s41467-021-22081-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/26/2021] [Indexed: 12/30/2022] Open
Abstract
137Cs is a long-lived (30-year radioactive half-life) fission product dispersed globally by mid-20th century atmospheric nuclear weapons testing. Here we show that vegetation thousands of kilometers from testing sites continues to cycle 137Cs because it mimics potassium, and consequently, bees magnify this radionuclide in honey. There were no atmospheric weapons tests in the eastern United States, but most honey here has detectable 137Cs at >0.03 Bq kg−1, and in the southeastern U.S., activities can be >500 times higher. By measuring honey, we show regional patterns in the biogeochemical cycling of 137Cs and conclude that plants and animals receive disproportionally high exposure to ionizing radiation from 137Cs in low potassium soils. In several cases, the presence of 137Cs more than doubled the ionizing radiation from gamma and x-rays in the honey, indicating that despite its radioactive half-life, the environmental legacy of regional 137Cs pollution can persist for more than six decades. Radioactive 137Cs is a fission product remaining in the environment from mid-20th century nuclear testing. Here the authors show that vegetation thousands of kilometers from testing sites continues to cycle 137Cs, and consequently, bees magnify this contaminant in honey in regions with low soil potassium.
Collapse
|
9
|
Nutrient Imbalance of the Host Plant for Larvae of the Pale Grass Blue Butterfly May Mediate the Field Effect of Low-Dose Radiation Exposure in Fukushima: Dose-Dependent Changes in the Sodium Content. INSECTS 2021; 12:insects12020149. [PMID: 33572324 PMCID: PMC7916146 DOI: 10.3390/insects12020149] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/27/2021] [Accepted: 02/05/2021] [Indexed: 12/21/2022]
Abstract
The pale grass blue butterfly Zizeeria maha is sensitive to low-dose radioactive pollution from the Fukushima nuclear accident in the field but is also highly tolerant to radioactive cesium (137Cs) in an artificial diet in laboratory experiments. To resolve this field-laboratory paradox, we hypothesize that the butterfly shows vulnerability in the field through biochemical changes in the larval host plant, the creeping wood sorrel Oxalis corniculata, in response to radiation stress. To test this field-effect hypothesis, we examined nutrient contents in the host plant leaves from Tohoku (mostly polluted areas including Fukushima), Niigata, and Kyushu, Japan. Leaves from Tohoku showed significantly lower sodium and lipid contents than those from Niigata. In the Tohoku samples, the sodium content (but not the lipid content) was significantly negatively correlated with the radioactivity concentration of cesium (137Cs) in leaves and with the ground radiation dose. The sodium content was also correlated with other nutrient factors. These results suggest that the sodium imbalance of the plant may be caused by radiation stress and that this nutrient imbalance may be one of the reasons that this monophagous butterfly showed high mortality and morphological abnormalities in the field shortly after the accident in Fukushima.
Collapse
|
10
|
Consecutive sexual maturation observed in a rock shell population in the vicinity of the Fukushima Daiichi Nuclear Power Plant, Japan. Sci Rep 2021; 11:560. [PMID: 33436968 PMCID: PMC7803997 DOI: 10.1038/s41598-020-80686-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/15/2020] [Indexed: 11/26/2022] Open
Abstract
In 2012, after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) that followed the Tohoku earthquake and tsunami in March 2011, no rock shell (Thais clavigera; currently recognized as Reishia clavigera; Gastropoda, Neogastropoda, Muricidae) specimens were found near the plant from Hirono to Futaba Beach (a distance of approximately 30 km). In July 2016, however, rock shells were again found to inhabit the area. From April 2017 to May 2019, we collected rock shell specimens monthly at two sites near the FDNPP (Okuma and Tomioka) and at a reference site ~ 120 km south of the FDNPP (Hiraiso). We examined the gonads of the specimens histologically to evaluate their reproductive cycle and sexual maturation. The gonads of the rock shells collected at Okuma, ~ 1 km south of the FDNPP, exhibited consecutive sexual maturation during the 2 years from April 2017 to May 2019, whereas sexual maturation of the gonads of specimens collected at Hiraiso was observed only in summer. The consecutive sexual maturation of the gonads of the specimens collected at Okuma might not represent a temporary phenomenon but rather a site-specific phenotype, possibly caused by specific environmental factors near the FDNPP.
Collapse
|
11
|
Tanaka S, Kinouchi T, Fujii T, Imanaka T, Takahashi T, Fukutani S, Maki D, Nohtomi A, Takahashi S. Observation of morphological abnormalities in silkworm pupae after feeding 137CsCl-supplemented diet to evaluate the effects of low dose-rate exposure. Sci Rep 2020; 10:16055. [PMID: 32994421 PMCID: PMC7524783 DOI: 10.1038/s41598-020-72882-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 09/08/2020] [Indexed: 11/29/2022] Open
Abstract
Since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, morphological abnormalities in lepidopteran insects, such as shrinkage and/or aberration of wings, have been reported. Butterflies experimentally exposed to radiocesium also show such abnormalities. However, because of a lack of data on absorbed dose and dose-effect relationship, it is unclear whether these abnormalities are caused directly by radiation. We conducted a low dose-rate exposure experiment in silkworms reared from egg to fully developed larvae on a 137CsCl-supplemented artificial diet and estimated the absorbed dose to evaluate morphological abnormalities in pupal wings. We used 137CsCl at 1.3 × 103 Bq/g fresh weight to simulate 137Cs contamination around the FDNPP. Absorbed doses were estimated using a glass rod dosimeter and Monte Carlo particle transport simulation code PHITS. Average external absorbed doses were approximately 0.24 (on diet) and 0.016 mGy/day (near diet); the average internal absorbed dose was approximately 0.82 mGy/day. Pupal wing structure is sensitive to radiation exposure. However, no significant differences were observed in the wing-to-whole body ratio of pupae between the 137CsCl-exposure and control groups. These results suggest that silkworms are insensitive to low dose-rate exposure due to chronic ingestion of high 137Cs at a high concentration.
Collapse
Affiliation(s)
- Sota Tanaka
- Research Group for Environmental Science, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan.
| | - Tadatoshi Kinouchi
- Division of Radiation Life Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan
| | - Tsuguru Fujii
- Laboratory of Creative Science for Insect Industries, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Nishi-ku, Motooka, Fukuoka, 819-0395, Japan
| | - Tetsuji Imanaka
- Division of Nuclear Engineering Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan
| | - Tomoyuki Takahashi
- Division of Nuclear Engineering Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan
| | - Satoshi Fukutani
- Division of Nuclear Engineering Science, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan
| | - Daisuke Maki
- Technical Staff Office, Institute for Integrated Radiation and Nuclear Science, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, 590-0494, Japan
| | - Akihiro Nohtomi
- Quantum Radiation Sciences, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-ku, Fukuoka City, 812-8582, Japan
| | - Sentaro Takahashi
- Professor Emeritus, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| |
Collapse
|
12
|
Hiyama A, Otaki JM. Dispersibility of the Pale Grass Blue Butterfly Zizeeria m aha (Lepidoptera: Lycaenidae) Revealed by One-Individual Tracking in the Field: Quantitative Comparisons between Subspecies and between Sexes. INSECTS 2020; 11:insects11020122. [PMID: 32074952 PMCID: PMC7073966 DOI: 10.3390/insects11020122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/07/2020] [Accepted: 02/12/2020] [Indexed: 11/16/2022]
Abstract
The pale grass blue butterfly Zizeeria maha (Lepidoptera: Lycaenidae) has been used as an environmental indicator species for radioactive pollution after the Fukushima nuclear accident. Here, based on the one-individual tracking method in the field, we examined dispersal-associated and other behavioral traits of this butterfly, focusing on two subspecies, Z. maha argia in mainland Japan and Z. maha okinawana in Okinawa. The accumulated distances in the adult lifespan were 18.9 km and 38.2 km in mainland and Okinawa males, respectively, and 15.0 km and 7.8 km in mainland and Okinawa females, respectively. However, the mean distance from the starting point was only 24.2 m and 21.1 m in the mainland and Okinawa males, respectively, and 13.7 m and 7.4 m in the mainland and Okinawa females, respectively. Some quantitative differences in resting and feeding were found between subspecies and between sexes. The ARIMA (autoregressive integrated moving average) model indicated that the dispersal distance was 52.3 m (99% confidence interval value of 706.6 m) from the starting point in mainland males. These results support the idea that despite some behavioral differences, both subspecies of this butterfly are suitable as an environmental indicator because of the small dispersal ranges.
Collapse
Affiliation(s)
- Atsuki Hiyama
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan
- Laboratory of Conservation Ecology, Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan
- Japan Butterfly Conservation Society, Tokyo 140-0014, Japan
| | - Joji M. Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan
- Correspondence: ; Tel.: +81-98-895-8557
| |
Collapse
|
13
|
Overwintering States of the Pale Grass Blue Butterfly Zizeeria maha (Lepidoptera: Lycaenidae) at the Time of the Fukushima Nuclear Accident in March 2011. INSECTS 2019; 10:insects10110389. [PMID: 31690046 PMCID: PMC6920751 DOI: 10.3390/insects10110389] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 01/02/2023]
Abstract
The Fukushima nuclear accident in March 2011 caused the massive release of anthropogenic radioactive materials from the Fukushima Dai-ichi Nuclear Power Plant to its surrounding environment. Its biological effects have been studied using the pale grass blue butterfly, Zizeeria maha (Lepidoptera: Lycaenidae), but the overwintering states of this butterfly remain elusive. Here, we conducted a series of field surveys in March 2018, March 2019, and April 2019 in Fukushima and its vicinity to clarify the overwintering states of this butterfly at the time of the Fukushima nuclear accident. We discovered overwintering individuals in situ associated with the host plant Oxalis corniculata under natural straw mulch as first-instar to fourth-instar larvae in March 2018 and 2019. No other developmental stages were found. The body length and width were reasonably correlated with the accumulated temperature. On the basis of a linear regression equation between body size and accumulated temperature, together with other data, we deduced that the pale grass blue butterfly occurred as fourth-instar larvae in Fukushima and its vicinity at the time of the accident. This study paves the way for subsequent dosimetric analyses that determine the radiation doses absorbed by the butterfly after the accident.
Collapse
|
14
|
Gurung RD, Taira W, Sakauchi K, Iwata M, Hiyama A, Otaki JM. Tolerance of High Oral Doses of Nonradioactive and Radioactive Caesium Chloride in the Pale Grass Blue Butterfly Zizeeria maha. INSECTS 2019; 10:E290. [PMID: 31505757 PMCID: PMC6780287 DOI: 10.3390/insects10090290] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 12/20/2022]
Abstract
The biological effects of the Fukushima nuclear accident have been examined in the pale grass blue butterfly, Zizeeria maha (Lepidoptera: Lycaenidae). In previous internal exposure experiments, larvae were given field-collected contaminated host plant leaves that contained up to 43.5 kBq/kg (leaf) of radioactive caesium. Larvae ingested up to 480 kBq/kg (larva), resulting in high mortality and abnormality rates. However, these results need to be compared with the toxicological data of caesium. Here, we examined the toxicity of both nonradioactive and radioactive caesium chloride on the pale grass blue butterfly. Larvae were fed a caesium-containing artificial diet, ingesting up to 149 MBq/kg (larva) of radioactive caesium (137Cs) or a much higher amount of nonradioactive caesium. We examined the pupation rate, eclosion rate, survival rate up to the adult stage, and the forewing size. In contrast to previous internal exposure experiments using field-collected contaminated leaves, we could not detect any effect. We conclude that the butterfly is tolerant to ionising radiation from 137Cs in the range tested but is vulnerable to radioactive contamination in the field. These results suggest that the biological effects in the field may be mediated through ecological systems and cannot be estimated solely based on radiation doses.
Collapse
Affiliation(s)
- Raj D Gurung
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
| | - Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
- Instrumental Research Center, University of the Ryukyus, Okinawa 903-0213, Japan.
| | - Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
| | - Masaki Iwata
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
- Department of International Agricultural Development, Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
| | - Atsuki Hiyama
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
- Japan Butterfly Conservation Society, Tokyo 140-0014, Japan.
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa 903-0213, Japan.
| |
Collapse
|
15
|
Loss SR, Dorning MA, Diffendorfer JE. Biases in the Literature on Direct Wildlife Mortality from Energy Development. Bioscience 2019. [DOI: 10.1093/biosci/biz026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Scott R Loss
- Assistant professor in the Department of Natural Resource Ecology and Management at Oklahoma State University. Scott studies multiple aspects of global change ecology, including impacts of energy development and other human-caused mortality sources on wildlife, invasive species ecology, and urban and disease ecology
| | - Monica A Dorning
- Research scientist at the US Geological Survey (USGS) Geosciences and Environmental Change Science Center in Denver, Colorado. Monica applies spatially explicit modeling approaches to study energy development, landscape change, and human–environment interactions
| | - Jay E Diffendorfer
- Research ecologist, also at the USGS Geosciences and Environmental Change Science Center in Denver, Colorado. Jay currently studies the energy–environment nexus, land change impacts, ecosystem services, and applied ecology
| |
Collapse
|
16
|
Developmental and hemocytological effects of ingesting Fukushima's radiocesium on the cabbage white butterfly Pieris rapae. Sci Rep 2019; 9:2625. [PMID: 30796244 PMCID: PMC6385249 DOI: 10.1038/s41598-018-37325-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/04/2018] [Indexed: 12/22/2022] Open
Abstract
High morphological abnormality and mortality rates have been reported in the pale grass blue butterfly, Zizeeria maha, since the Fukushima nuclear accident. However, it remains uncertain if these effects are restricted to this butterfly. Here, we evaluated the effects of ingesting cabbage leaves grown with contaminated soils from Fukushima on the development and hemocytes of the cabbage white butterfly, Pieris rapae. Contaminated cabbage leaves containing various low levels of anthropogenic 134Cs and 137Cs radioactivity (less than natural 40K radioactivity) were fed to larvae from Okinawa, the least contaminated locality in Japan. Negative developmental and morphological effects were detected in the experimental groups. The cesium (but not potassium) radioactivity concentration was negatively correlated with the granulocyte percentage in hemolymph, and the granulocyte percentage was positively correlated with the pupal eclosion rate, the adult achievement rate, and the total normality rate. These results demonstrated that ingesting low-level radiocesium contaminants in Fukushima (but not natural radiopotassium) imposed biologically negative effects on the cabbage white butterfly, as in the pale grass blue butterfly, at both cellular and organismal levels.
Collapse
|
17
|
Hancock S, Vo NTK, Omar-Nazir L, Batlle JVI, Otaki JM, Hiyama A, Byun SH, Seymour CB, Mothersill C. Transgenerational effects of historic radiation dose in pale grass blue butterflies around Fukushima following the Fukushima Dai-ichi Nuclear Power Plant meltdown accident. ENVIRONMENTAL RESEARCH 2019; 168:230-240. [PMID: 30321736 DOI: 10.1016/j.envres.2018.09.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 06/08/2023]
Abstract
Low dose radiation effects have been investigated in Chernobyl for many years but there is uncertainty about initial doses received by many animal species. However, the Fukushima Dai-ichi Nuclear Power Plant accident opens an opportunity to study the effects of the initial low historic dose on directly exposed species and their progeny during a time where the contaminating radionuclides are decaying. In this paper, it is proposed that historic acute exposure and its resulting non-targeted effects (NTEs) may be partially involved in the high mortality/abnormality rates seen across generations of pale grass blue butterflies (Zizeeria maha) around Fukushima. Data from Hiyama et al. (2012) on the morphological abnormality frequencies in Z. maha collected around Fukushima and their progeny were used in this paper. Two dose reconstruction methods based on the Gaussian plume model were used to determine the external absorbed dose to the first exposed generation from both ground shine and plume shine. One method involved the use of the dose rate recorded at the time of collection and only took Cs-137 into account. The other involved using release rates and atmospheric conditions to determine the doses and considered Cs-137 and Cs-134. The reconstructed doses were plotted against the mortality rates and abnormality frequencies across generations. The mortality rates of the progeny from irradiated progenitors increased linearly with the increasing historic radiation doses reconstructed using both Cs-137 and Cs-134 sources. Additionally, a higher level of morphological abnormalities was observed in progeny than in the progenitors. The mean abnormality frequencies also increased throughout generations. As these results are a sign of NTEs being involved, it can be suggested that increasing mutation levels across generations may result, in part, from NTEs induced by the initial low dose received by the first exposed generation. However, continual accumulation of mutations over generations in their natural contaminated habitats remains a likely contributor into the observed outcome.
Collapse
Affiliation(s)
- Samuel Hancock
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Nguyen T K Vo
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Laila Omar-Nazir
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | | | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara, Okinawa 903-0123, Japan
| | - Atsuki Hiyama
- Laboratory of Conservation Ecology, Department of Integrated Science and Engineering for Sustainable Society, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Soo Hyun Byun
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Colin B Seymour
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Carmel Mothersill
- Department of Biology, McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
18
|
Giraudeau M, Bonzom JM, Ducatez S, Beaugelin-Seiller K, Deviche P, Lengagne T, Cavalie I, Camilleri V, Adam-Guillermin C, McGraw KJ. Carotenoid distribution in wild Japanese tree frogs (Hyla japonica) exposed to ionizing radiation in Fukushima. Sci Rep 2018; 8:7438. [PMID: 29743616 PMCID: PMC5943346 DOI: 10.1038/s41598-018-25495-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/03/2018] [Indexed: 12/28/2022] Open
Abstract
The nuclear accident in the Fukushima prefecture released a large amount of artificial radionuclides that might have short- and long-term biological effects on wildlife. Ionizing radiation can be a harmful source of reactive oxygen species, and previous studies have already shown reduced fitness effects in exposed animals in Chernobyl. Due to their potential health benefits, carotenoid pigments might be used by animals to limit detrimental effects of ionizing radiation exposure. Here, we examined concentrations of carotenoids in blood (i.e. a snapshot of levels in circulation), liver (endogenous carotenoid reserves), and the vocal sac skin (sexual signal) in relation to the total radiation dose rates absorbed by individual (TDR from 0.2 to 34 µGy/h) Japanese tree frogs (Hyla japonica). We found high within-site variability of TDRs, but no significant effects of the TDR on tissue carotenoid levels, suggesting that carotenoid distribution in amphibians might be less sensitive to ionizing radiation exposure than in other organisms or that the potential deleterious effects of radiation exposure might be less significant or more difficult to detect in Fukushima than in Chernobyl due to, among other things, differences in the abundance and mixture of each radionuclide.
Collapse
Affiliation(s)
- Mathieu Giraudeau
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA.
- Centre for Ecology & Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK.
| | - Jean-Marc Bonzom
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint Paul Lez Durance, France.
| | - Simon Ducatez
- School of Biological Sciences A08, University of Sydney, Sydney, NSW 2006, Australia
| | - Karine Beaugelin-Seiller
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint Paul Lez Durance, France
| | - Pierre Deviche
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA
| | - Thierry Lengagne
- Université de Lyon 1, CNRS, UMR 5023, Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, Bât. Darwin C, F-69622, Villeurbanne Cedex, France
| | - Isabelle Cavalie
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint Paul Lez Durance, France
| | - Virginie Camilleri
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint Paul Lez Durance, France
| | - Christelle Adam-Guillermin
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SRTE/LECO, Cadarache, 13115, Saint Paul Lez Durance, France
| | - Kevin J McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA
| |
Collapse
|
19
|
Otaki JM, Taira W. Current Status of the Blue Butterfly in Fukushima Research. J Hered 2018; 109:178-187. [PMID: 28431090 DOI: 10.1093/jhered/esx037] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/12/2017] [Indexed: 11/14/2022] Open
Abstract
Adverse biological impacts of the Fukushima nuclear accident have been revealed using the pale grass blue butterfly, Zizeeria maha, since 2012, which were often considered incompatible with the conventional understanding of radiation biology. This discrepancy likely originates from different system conditions and methodologies. In this article, we first respond to comments from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) regarding our study; "technical errors" in unit usage and mathematical models noted by UNSCEAR are not errors but reflect our research philosophy not to introduce theoretical assumptions associated with unit conversion and mathematical fit. Second, we review our recent studies to support the original 2012 conclusions. Because the high morphological abnormality rate and small body size detected in Fukushima in 2011 have already ceased, likely through adaptive evolution, their present geographical distributions were investigated throughout Japan. Local populations showing relatively high abnormality rates and small body sizes were rare and basically restricted to Miyagi and its northern populations excluding the Fukushima populations, supporting the causal involvement of the accident. Lastly, we stress the importance of understanding the whole picture of the biological impacts of the Fukushima accident. In addition to the direct radiation impacts, indirect impacts through unknown radiation-associated mechanisms, such as immunological responses to insoluble particulate matter and nutritional deficiencies in plants and animals, would be in effect. Further environmental studies beyond conventional radiation biology and physics are necessary to understand the complex responses of organisms, including humans, to the Fukushima nuclear accident.
Collapse
Affiliation(s)
- Joji M Otaki
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, Japan
| | - Wataru Taira
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, Japan
| |
Collapse
|
20
|
Nohara C, Hiyama A, Taira W, Otaki JM. Robustness and Radiation Resistance of the Pale Grass Blue Butterfly from Radioactively Contaminated Areas: A Possible Case of Adaptive Evolution. J Hered 2018; 109:188-198. [PMID: 28199653 DOI: 10.1093/jhered/esx012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/07/2017] [Indexed: 11/13/2022] Open
Abstract
The pale grass blue butterfly, Zizeeria maha, has been used to evaluate biological impacts of the Fukushima nuclear accident in March 2011. Here, we examined the possibility that butterflies have adapted to be robust in the contaminated environment. Larvae (n = 2432) were obtained from adult butterflies (n = 20) collected from 7 localities with various contamination levels in May 2012, corresponding to the 7th generation after the accident. When the larvae were reared on non-contaminated host plant leaves from Okinawa, the normality rates of natural exposure without artificial irradiation (as an indication of robustness) were high not only in the least contaminated locality but also in the most contaminated localities. The normality rates were similarly obtained when the larvae were reared on non-contaminated leaves with external irradiation or on contaminated leaves from Fukushima to deliver internal irradiation. The normality rate of natural exposure and that of external or internal exposure were correlated, suggesting that radiation resistance (or susceptibility) likely reflects general state of health. The normality rate of external or internal exposure was divided by the relative normality rate of natural exposure, being defined as the resistance value. The resistance value was the highest in the populations of heavily contaminated localities and was inversely correlated with the distance from the Fukushima Dai-ichi nuclear power plant. These results suggest that the butterfly population might have adapted to the contaminated environment within approximately 1 year after the accident. The present study may partly explain the decrease in mortality and abnormality rates later observed in the contaminated areas.
Collapse
Affiliation(s)
- Chiyo Nohara
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Atsuki Hiyama
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Wataru Taira
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Joji M Otaki
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan
| |
Collapse
|
21
|
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.
Collapse
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
| |
Collapse
|
22
|
Takino S, Yamashiro H, Sugano Y, Fujishima Y, Nakata A, Kasai K, Hayashi G, Urushihara Y, Suzuki M, Shinoda H, Miura T, Fukumoto M. Analysis of the Effect of Chronic and Low-Dose Radiation Exposure on Spermatogenic Cells of Male Large Japanese Field Mice ( Apodemus speciosus ) after the Fukushima Daiichi Nuclear Power Plant Accident. Radiat Res 2017; 187:161-168. [PMID: 28092218 DOI: 10.1667/rr14234.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this study we analyzed the effect of chronic and low-dose-rate (LDR) radiation on spermatogenic cells of large Japanese field mice ( Apodemus speciosus ) after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident. In March 2014, large Japanese field mice were collected from two sites located in, and one site adjacent to, the FNPP ex-evacuation zone: Tanashio, Murohara and Akogi, respectively. Testes from these animals were analyzed histologically. External dose rate from radiocesium (combined 134Cs and 137Cs) in these animals at the sampling sites exhibited 21 μGy/day in Tanashio, 304-365 μGy/day in Murohara and 407-447 μGy/day in Akogi. In the Akogi group, the numbers of spermatogenic cells and proliferating cell nuclear antigen (PCNA)-positive cells per seminiferous tubule were significantly higher compared to the Tanashio and Murohara groups, respectively. TUNEL-positive apoptotic cells tended to be detected at a lower level in the Murohara and Akogi groups compared to the Tanashio group. These results suggest that enhanced spermatogenesis occurred in large Japanese field mice living in and around the FNPP ex-evacuation zone. It remains to be elucidated whether this phenomenon, attributed to chronic exposure to LDR radiation, will benefit or adversely affect large Japanese field mice.
Collapse
Affiliation(s)
- Sachio Takino
- a Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan
| | - Hideaki Yamashiro
- a Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan
| | - Yukou Sugano
- a Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan
| | - Yohei Fujishima
- b Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan
| | - Akifumi Nakata
- c Division of Life Science, Hokkaido Pharmaceutical University School of Pharmacy, 7-15-4-1 Maeda, Teine, Sapporo, 006-8590, Japan; and
| | - Kosuke Kasai
- b Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan
| | | | | | | | - Hisashi Shinoda
- e Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aobaku, Sendai, 980-8575, Japan
| | - Tomisato Miura
- b Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan
| | | |
Collapse
|
23
|
Otaki JM. Fukushima's lessons from the blue butterfly: A risk assessment of the human living environment in the post-Fukushima era. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2016; 12:667-672. [PMID: 27640413 DOI: 10.1002/ieam.1828] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/11/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
A series of studies on the pale grass blue butterfly that were carried out to assess the biological effects of the Fukushima nuclear accident teach 3 important lessons. First, it is necessary to have an environmental indicator species, such as the pale grass blue butterfly in Japan, that is common (not endangered), shares a living environment (air, water, and soil) with humans, and is amenable to laboratory experiments. The monitoring of such indicator species before and immediately after a nuclear accident likely reflects acute impacts caused by initial exposure. To assess transgenerational and chronic effects, continuous monitoring over time is encouraged. Second, it is important to understand the actual health status of a polluted region and comprehend the whole picture of the pollution impacts, rather than focusing on the selected effects of radiation alone. In our butterfly experiments, plant leaves from Fukushima were fed to larval butterflies to access whole-body effects, focusing on survival rate and morphological abnormalities (rather than focusing on a specific disease or biochemical marker). Our results revealed that ionizing radiation is unlikely to be the exclusive source of environmental disturbances. Airborne particulate matter from a nuclear reactor, regardless of its radioactivity, is likely equally important. Finally, our butterfly experiments demonstrate that there is considerable variation in sensitivities to nuclear pollution within a single species or even within a local population. Based on these results, it is speculated that high pollution sensitivity in humans may be caused not only by low levels of functional DNA repair enzymes but also by immunological responses to particulate matter in the respiratory tract. These lessons from the pale grass blue butterfly should be integrated in studying future nuclear pollution events and decision making on nuclear and environmental policies at the local and international levels in the postFukushima era. Integr Environ Assess Manag 2016;12:667-672. © 2016 SETAC.
Collapse
Affiliation(s)
- Joji M Otaki
- BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, Japan.
| |
Collapse
|
24
|
Gurung RD, Iwata M, Hiyama A, Taira W, Degnan B, Degnan S, Otaki JM. Comparative Morphological Analysis of the Immature Stages of the Grass Blue Butterflies Zizeeria and Zizina (Lepidoptera: Lycaenidae). Zoolog Sci 2016; 33:384-400. [PMID: 27498798 DOI: 10.2108/zs150171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The pale grass blue butterfly has been used to assess the biological effects of the Fukushima nuclear accident. Zizeeria and Zizina are two closely related genera of grass blue butterflies that are widely distributed in tropical to temperate Asia, Australia, and Africa, making them suitable environmental indicators for these areas. However, the morphological features of the immature stages have been examined only in fragmentary fashion. Here, we reared Zizeeria maha argia, Zizeeria maha okinawana, Zizeeria karsandra karsandra, Zizina emelina emelina, Zizina otis labradus, and Zizina otis riukuensis using a standard rearing method that was developed for Zizeeria maha, and comparatively identified morphological traits to effectively classify the immature stages of species or subspecies. Morphological information on these and other subspecies including Zizeeria knysna knysna and Zizina otis antanossa from Africa was also collected from literature. The subspecies were all reared successfully. The subspecies all had dorsal nectary and tentacle organs with similar morphology. For the subspecies of Zizeeria maha, only minor morphological differences were noted. Similarly, the subspecies of Zizina otis shared many traits. Most importantly, Zizeeria and Zizina differed in the shape of the sensory hairs that accompany the dorsal nectary organ; Zizeeriahad pointed hairs, and Zizina had blunt or rounded hairs. However, Zizina emelina exhibited several intermediate features between these two genera. Overall, the morphological traits did not completely reflect the conventional systematic relationships. This comparative study describes the efficient rearing of the grass blue butterflies and provides a morphological basis for the use of these species as environmental indicators.
Collapse
Affiliation(s)
- Raj D Gurung
- 1 The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science,Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Masaki Iwata
- 1 The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science,Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Atsuki Hiyama
- 1 The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science,Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Wataru Taira
- 1 The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science,Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Bernard Degnan
- 2 Faculty of Science, School of Biological Sciences, University of Queensland,St. Lucia, Brisbane, QLD 4072, Australia
| | - Sandie Degnan
- 2 Faculty of Science, School of Biological Sciences, University of Queensland,St. Lucia, Brisbane, QLD 4072, Australia
| | - Joji M Otaki
- 1 The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science,Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| |
Collapse
|
25
|
Abstract
Protection of the environment is integral to the system of radiological protection, as outlined in the 2007 Recommendations of the International Commission on Radiological Protection (ICRP, Publication 103). The Commission's activities in this area are mainly pursued by Committee 5 and its associated Task Groups. Publication 91 broadly outlines the approach to radiological protection of the environment, and its alignment with approaches to environmental protection from hazardous substances in general. Publications 108 and 114 provide the cornerstones of the environmental protection system and relevant databases. Publication 124 considers its application in planned, existing, and emergency exposure situations. The system centres on 12 Reference Animals and Plants (RAPs) with broad relevance for environmental protection based on their ubiquity and significance as well as other criteria, as described in Publication 108 The databases comprise general biology of the RAPs, transfer parameters, dose conversion coefficients, and effects data. Derived Consideration Reference Levels (DCRLs) were established for each RAP; a DCRL represents a band of dose rates that might result in some deleterious effects in individuals of that type of RAP. Newly established Task Group 99 will compile the RAP-specific reference information into monographs, with the view of updating information and improving the applicability of the system in different exposure situations. For certain scenarios, more precise and ecosystem-specific protection benchmarks may be justified, which would have to be informed by consideration of representative organisms (i.e. representative of a particular ecosystem and relevant to the specific scenario; Publication 124). Committee 5 will explore this further, making use of a limited number of case studies.
Collapse
Affiliation(s)
- C-M Larsson
- Australian Radiation Protection and Nuclear Safety Agency, PO Box 655, Miranda, NSW 2228, Australia
| |
Collapse
|
26
|
Taira W, Hiyama A, Nohara C, Sakauchi K, Otaki JM. Ingestional and transgenerational effects of the Fukushima nuclear accident on the pale grass blue butterfly. JOURNAL OF RADIATION RESEARCH 2015; 56 Suppl 1:i2-i18. [PMID: 26661851 PMCID: PMC4732531 DOI: 10.1093/jrr/rrv068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/14/2015] [Accepted: 10/04/2015] [Indexed: 06/01/2023]
Abstract
One important public concern in Japan is the potential health effects on animals and humans that live in the Tohoku-Kanto districts associated with the ingestion of foods contaminated with artificial radionuclides from the collapsed Fukushima Dai-ichi Nuclear Power Plant. Additionally, transgenerational or heritable effects of radiation exposure are also important public concerns because these effects could cause long-term changes in animal and human populations. Here, we concisely review our findings and implications related to the ingestional and transgenerational effects of radiation exposure on the pale grass blue butterfly, Zizeeria maha, which coexists with humans. The butterfly larval ingestion of contaminated leaves found in areas of human habitation, even at low doses, resulted in morphological abnormalities and death for some individuals, whereas other individuals were not affected, at least morphologically. This variable sensitivity serves as a basis for the adaptive evolution of radiation resistance. The distribution of abnormality and mortality rates from low to high doses fits well with a Weibull function model or a power function model. The offspring generated by morphologically normal individuals that consumed contaminated leaves exhibited high mortality rates when fed contaminated leaves; importantly, low mortality rates were restored when they were fed non-contaminated leaves. Our field monitoring over 3 years (2011-2013) indicated that abnormality and mortality rates peaked primarily in the fall of 2011 and decreased afterwards to normal levels. These findings indicate high impacts of early exposure and transgenerationally accumulated radiation effects over a specific period; however, the population regained normality relatively quickly after ∼15 generations within 3 years.
Collapse
Affiliation(s)
- Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Atsuki Hiyama
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Chiyo Nohara
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Ko Sakauchi
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| |
Collapse
|
27
|
Iwata M, Taira W, Hiyama A, Otaki JM. The Lycaenid Central Symmetry System: Color Pattern Analysis of the Pale Grass Blue Butterfly Zizeeria maha. Zoolog Sci 2015; 32:233-9. [PMID: 26003977 DOI: 10.2108/zs140249] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The nymphalid groundplan has been proposed to explain diverse butterfly wing color patterns. In this model, each symmetry system is composed of a core element and a pair of paracore elements. The development of this elemental configuration has been explained by the induction model for positional information. However, the diversity of color patterns in other butterfly families in relation to the nymphalid groundplan has not been thoroughly examined. Here, we examined aberrant color pattern phenotypes of a lycaenid butterfly, Zizeeria maha, from mutagenesis and plasticity studies as well as from field surveys. In several mutants, the third and fourth spot arrays were coordinately positioned much closer to the discal spot in comparison to the normal phenotype. In temperature-shock types, the third and fourth array spots were elongated inwardly or outwardly from their normal positions. In field-caught spontaneous mutants, small black spots were located adjacent to normal black spots. Analysis of these aberrant phenotypes indicated that the spots belonging to the third and fourth arrays are synchronously changeable in position and shape around the discal spot. Thus, these arrays constitute paracore elements of the central symmetry system of the lycaenid butterflies, and the discal spot comprises the core element. These aberrant phenotypes can be explained by the black-inducing signals that propagate from the prospective discal spot, as predicted by the induction model. These results suggest the existence of long-range developmental signals that cover a large area of a wing not only in nymphalid butterflies, but also in lycaenid butterflies.
Collapse
Affiliation(s)
- Masaki Iwata
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | | | | | | |
Collapse
|
28
|
Taira W, Iwasaki M, Otaki JM. Body size distributions of the pale grass blue butterfly in Japan: Size rules and the status of the Fukushima population. Sci Rep 2015. [PMID: 26197998 PMCID: PMC4510528 DOI: 10.1038/srep12351] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The body size of the pale grass blue butterfly, Zizeeria maha, has been used as an environmental indicator of radioactive pollution caused by the Fukushima nuclear accident. However, geographical and temporal size distributions in Japan and temperature effects on size have not been established in this species. Here, we examined the geographical, temporal, and temperature-dependent changes of the forewing size of Z. maha argia in Japan. Butterflies collected in 2012 and 2013 from multiple prefectures throughout Japan demonstrated an inverse relationship of latitude and forewing size, which is the reverse of Bergmann’s cline. The Fukushima population was significantly larger than the Aomori and Miyagi populations and exhibited no difference from most of the other prefectural populations. When monitored at a single geographic locality every other month, forewing sizes were the largest in April and the smallest in August. Rearing larvae at a constant temperature demonstrated that forewing size followed the temperature-size rule. Therefore, the converse Bergmann’s rule and the temperature-size rule coexist in this multivoltine species. Our study establishes this species as a useful environmental indicator and supports the idea that the size reduction observed only in Fukushima Prefecture in 2011 was caused by the environmental stress of radioactive pollution.
Collapse
Affiliation(s)
- Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Mayo Iwasaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| |
Collapse
|
29
|
Hiyama A, Taira W, Nohara C, Iwasaki M, Kinjo S, Iwata M, Otaki JM. Spatiotemporal abnormality dynamics of the pale grass blue butterfly: three years of monitoring (2011-2013) after the Fukushima nuclear accident. BMC Evol Biol 2015; 15:15. [PMID: 25888050 PMCID: PMC4335452 DOI: 10.1186/s12862-015-0297-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 01/27/2015] [Indexed: 12/22/2022] Open
Abstract
Background Long-term monitoring of the biological impacts of the radioactive pollution caused by the Fukushima nuclear accident in March 2011 is required to understand what has occurred in organisms living in the polluted areas. Here, we investigated spatial and temporal changes of the abnormality rate (AR) in both field-caught adult populations and laboratory-reared offspring populations of the pale grass blue butterfly, Zizeeria maha, which has generation time of approximately one month. We monitored 7 localities (Fukushima, Motomiya, Hirono, Iwaki, Takahagi, Mito, and Tsukuba) every spring and fall over 3 years (2011–2013). Results The adult ARs of these localities quickly increased and peaked in the fall of 2011, which was not observed in non-contaminated localities. In the offspring generation, the total ARs, which include deaths at the larval, prepupal, and pupal stages and morphological abnormalities at the adult stage, peaked either in the fall of 2011 or in the spring of 2012, with much higher levels than those of the parent field populations, suggesting that high incidence of deaths and abnormalities might have occurred in the field populations. Importantly, the elevated ARs of the field and offspring populations settled back to a normal level by the fall of 2012 and by the spring of 2013, respectively. Similar results were obtained not only in the spatiotemporal dynamics of the number of individuals caught per minute but also in the temporal dynamics of the correlation coefficient between the adult abnormality rate and the ground radiation dose or the distance from the Power Plant. Conclusions These results demonstrated an occurrence and an accumulation of adverse physiological and genetic effects in early generations, followed by their decrease and leveling off at a normal level, providing the most comprehensive record of biological dynamics after a nuclear accident available today. This study also indicates the importance of considering generation time and adaptive evolution in evaluating the biological impacts of artificial pollution in wild organisms. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0297-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Atsuki Hiyama
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Wataru Taira
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Chiyo Nohara
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Mayo Iwasaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Seira Kinjo
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Masaki Iwata
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Okinawa, 903-0213, Japan.
| |
Collapse
|
30
|
Ruedig E, Beresford NA, Gomez Fernandez ME, Higley K. A comparison of the ellipsoidal and voxelized dosimetric methodologies for internal, heterogeneous radionuclide sources. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2015; 140:70-77. [PMID: 25461518 DOI: 10.1016/j.jenvrad.2014.11.004] [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: 08/22/2014] [Revised: 11/03/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
Non-human biota dosimetry has historically relied on ellipsoidal dosimetric phantoms. In 2008, the International Commission on Radiological Protection (ICRP) presented a set of ellipsoidal models representative of wildlife, including dosimetric data for homogeneously distributed internal radionuclide sources. Such data makes it possible to quickly and easily estimate radiation dose rate. Voxelized modeling, first developed for use in human medical dosimetry, utilizes advanced imaging technologies to generate realistic and detailed dosimetric phantoms. Individual organs or tissues may be segmented and dosimetric data derived for each anatomic area of interest via Monte Carlo modeling. Recently, dosimetric data derived from voxelized models has become available for organisms similar to the ICRP's Reference Animals and Plants in 2008. However, if the existing ellipsoidal models are conservative, there may be little need to employ voxel models in regulatory assessments. At the same time, existing dosimetric techniques may be inadequate to resolve recent controversies surrounding the impact of ionizing radiation exposure on wildlife. This study quantifies the difference between voxel-calculated and ellipsoid-calculated dose rates for seven radionuclides assumed to be heterogeneously distributed: (14)C, (36)Cl, (60)Co, (90)Sr, (131)I, (134)Cs, (137)Cs, and (210)Po. Generally, the two methodologies agree within a factor of two to three. Finally, this paper compares the assumptions of each dosimetric system, the conditions under which each model best applies, and the implications that our results have for the ongoing dialog surrounding wildlife dosimetry.
Collapse
Affiliation(s)
- Elizabeth Ruedig
- Colorado State University, Department of Environmental & Radiological Health Sciences, Fort Collins, CO 80523, USA.
| | - Nicholas A Beresford
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP, UK
| | | | - Kathryn Higley
- Oregon State University, Department of Nuclear Engineering & Radiation Health Physics, Corvallis, OR 97331, USA
| |
Collapse
|
31
|
Nohara C, Taira W, Hiyama A, Tanahara A, Takatsuji T, Otaki JM. Ingestion of radioactively contaminated diets for two generations in the pale grass blue butterfly. BMC Evol Biol 2014; 14:193. [PMID: 25330067 PMCID: PMC4171559 DOI: 10.1186/s12862-014-0193-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/19/2014] [Indexed: 11/10/2022] Open
Abstract
Background The release of radioactive materials due to the Fukushima nuclear accident has raised concern regarding the biological impacts of ingesting radioactively contaminated diets on organisms. We previously performed an internal exposure experiment in which contaminated leaves collected from polluted areas were fed to larvae of the pale grass blue butterfly, Zizeeria maha, from Okinawa, which is one of the least polluted localities in Japan. Using the same experimental system, in the present study, we further examined the effects of low-level-contaminated diets on this butterfly. Leaves were collected from two localities in Tohoku (Motomiya (161 Bq/kg) and Koriyama (117 Bq/kg)); two in Kanto (Kashiwa (47.6 Bq/kg) and Musashino (6.4 Bq/kg)); one in Tokai (Atami (2.5 Bq/kg)); and from Okinawa (0.2 Bq/kg). In addition to the effects on the first generation, we examined the possible transgenerational effects of the diets on the next generation. Results In the first generation, the Tohoku groups showed higher rates of mortality and abnormalities and a smaller forewing size than the Okinawa group. The mortality rates were largely dependent on the ingested dose of caesium. The survival rates of the Kanto-Tokai groups were greater than 80%, but the rates in the Tohoku groups were much lower. In the next generation, the survival rates in the Tohoku groups were below 20%, whereas those of the Okinawa groups were above 70%. The survival rates in the second generation were independent of the locality of the leaves ingested by the first generation, indicating that the diet in the second generation was the determinant of their survival. Moreover, a smaller forewing size was observed in the Tohoku groups in the second generation. However, the forewing size was inversely correlated with the cumulative caesium dose ingested throughout the first and second generations, indicating that the diet in the first generation also influenced the forewing size of the second generation. Conclusions Biological effects are detectable under a low ingested dose of radioactivity from a contaminated diet. The effects are transgenerational but can be overcome by ingesting a non-contaminated diet, suggesting that at least some of the observed effects are attributable to non-genetic physiological changes.
Collapse
|
32
|
Steen TY, Mousseau T. Outcomes of Fukushima: Biological Effects of Radiation on Nonhuman Species. J Hered 2014; 105:702-3. [DOI: 10.1093/jhered/esu049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|