Symposium
Radiation Monitoring and Conservation of Wildlife after Fukushima.

Symposium
Radiation Monitoring and Conservation of Wildlife after Fukushima.

Wednesday, Jul 29, 2015, 1:00 PM - 6:10 PM

The Sapporo Convention Center
1-1-1 Higashi-Sapporo 6-jo, Shiroishi-ku, Sapporo, 003-0006, Japan
TEL: +81-11-817-1010
FAX: +81-11-820-4300
URL: http://www.sora-scc.jp

This symposium is held as one of the symposia of the 5th International Wildlife Management Conference.

Supported By

Kyoto University Primate Research Institute Cooperative Research Fund

Organizers

Shoji Kawamura, University of Tokyo, Kashiwa, Japan
Tomoko Y. Steen, Georgetown University, Washington, DC, USA
Yuji Takenoshita, Chubu Gakuin University, Kagamigahara, Japan
Yoshi Kawamoto, Kyoto University, Inuyama, Japan
Jun Nakatani, National Agricultural Research Center, Tsukuba, Japan
Toru Oi, Ishikawa Prefectural University, Nonoichi, Japan
Fumio Yamada, Forestry and Forest Products Institute, Tsukuba, Japan

 

Presentations:

13:00-13:05 Shoji Kawamoto (The University of Tokyo)
Lead organizer

13:05-13:35 Satoshi Yoshida (National Institute of Radiological Sciences)
International Research Needs for the Effects of Radiation on Non-Human Biota and Ecosystems.

13:35-14:05 Manabu Fukumoto, Yusuke Urushihara, Masatoshi Suzuki, Yoshikazu Kuwahara, Gohei Hayashi (Tohoku University)
Establishment of Animal Archives in and around the Ex-Evacuation Zone of the Fukushima Nuclear Power Plant Accident.

14:05-14:35 Takuya Kato (Nippon Veterinary and Life Science University)
Hematological Characteristics and Muscle Radiocesium Concentrations in Wild Japanese Monkeys after Fukushima Disaster.

14:35-15:05 Joji Otaki, Atsuki Hiyama, Wataru Taira, Chiyo Nohara, Mayo Iwasaki, Seira Kinjo, Masaki Iwata (University of the Ryukyus)
The Pale Grass Blue Butterfly in Fukushima.

15:05-15:35 Shin-ichi Akimoto, Izumi Yao (Hokkaido University)
Effects of Radioactive Contamination around Fukushima Daiichi on the Morphology and Genetics of Aphids.

15:35-15:45 Break

15:45-16:15 Isao Nishiumi (National Museum of Nature and Science)
Research on Breeding of Ural Owl Using Nest-Boxes in Fukushima.

16:15-16:45 Tatsuo Aono (National Institute of Radiological Sciences)
The Effects of Radiation for Non-Human Biota in Marine Environment since the Fukushima NPS Accident.

16:45-17:15 Tomoko Steen (Georgetown University)
Studying Immunological Effects of Ionizing Radiation through Microbiome.

17:15-18:10 Discussion
Commentator Thimothy Mousseau (University of South Carolina)

　

Outline

Four years has passed since the accident at the Fukushima Daiichi Nuclear power plant. The event released and still continues to release ionizing radiation into the environment. Sporadic data on the exposure to ionizing radiation of wildlife have been produced over the years. However, the overall assessments of the actual condition and effective measures to manage and protect the future of wildlife in the area have not been developed, especially due to the limitations of scientists’ access to the area. In particular there is very limited knowledge on the biological effects of low level radiation and if threshold exposures exist. In this symposium, we report recent methods to monitor ionizing radiation developed individually by scientists working on specific wild animals namely, insects, birds, marine animals, and mammals including primates. We will also further our discussion to key issues on wildlife management. The Fukushima nuclear power plant accident and several subsequent events there have resulted in the accidental release of high levels of ionizing radiation on the soil, underground water, atmosphere, and ocean. The purpose of the symposium is to create a place to share, discuss and analyze future research plans for assessing, monitoring, and managing radioactive effects on wildlife in Fukushima and beyond, using multi-disciplinary approaches offered by experts in broad range of wildlife species. Commentator: Timothy Mousseau, University of South Carolina, Columbia, SC 29208, USA

 

Abstracts

International Research Needs for the Effects of Radiation on Non-Human Biota and Ecosystems.

Satoshi Yoshida
National Institute of Radiological Sciences

Most of the present systems of radiation protection have been developed to protect human health. However, increasing attention has been paid over the last two decades on the protection of the environment (i.e., non-human biota and ecosystems) from ionizing radiation. International organizations, such as International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), have organized meetings on environmental effect of radiation and published the up-to-date outcome as official reports. A series of European projects have played an important role in collecting scientific data currently available. However, they have also pointed out existing gaps of data. For example, data on the effect of exposed radiation dose (especially by chronic exposure) on biota is limited though essential for risk assessment. Many projects have attempted risk assessment in the contaminated areas of Chernobyl. Radiation exposure by the accident of Fukushima Daiichi Nuclear Power Plant in 2011 could be at a considerable level for non-human biota in highly contaminated areas, according to the derived consideration reference levels (DCRLs) proposed by ICRP. Although an extreme consequence, such as “red forests” seen in Chernobyl, has not been observed in Fukushima, several existing studies note possible effects of radiation exposure on some species in biota. This paper summarizes international and national efforts to protect non-human biota from ionizing radiation in the last two decades, and discusses research needs after the accident of Fukushima Daiichi Nuclear Power Plant.

Establishment of Animal Archives in and around the Ex-Evacuation Zone of the Fukushima Nuclear Power Plant Accident.

Manabu Fukumoto, Yusuke Urushihara, Masatoshi Suzuki, Yoshikazu Kuwahara and Gohei Hayashi
Institute of Development Aging and Cancer, Tohoku University

We have been establishing an archive system composed of animal tissue, grass and soil samples in and around the ex-evacuation zone of the Fukushima Nuclear Power Plant (FNPP) accident. We intend to make use of it for the assessment of radiation effects on ecosystem and the future radioprotection. As of December 1, 2014, we collected samples from 301 cattle, 57 pigs and 162 Japanese macaques. Four years after the accident, among radionuclides attributable to the accident, only radiocesium was detectable. Radiocesium concentration in each organ was proportional to that in peripheral blood and the highest in the skeletal muscle among organs examined irrespective of animal species. However, we have not observed abnormal findings in animals in and around the ex-evacuation including the leukocyte count in peripheral blood of Japanese macaques. Some of anti-oxidant activities examined were significantly correlated with the blood radiocesium level in cattle. These observations suggest that animals affected by the FNPP accident are under a stressful environment. However, we need a long-term follow-up study for decades to conclude whether the notions above are correct and how irradiation is involved in them.

　

Hematological Characteristics and Muscle Radiocesium Concentrations in Wild Japanese Monkeys after Fukushima Disaster.

Takuya Kato
Nippon Veterinary and Life Science University

The objective of this study is to monitor concentration of radiocesium Cs-134 and Cs-137 over time in the muscle of Japanese monkeys (Macaca fuscata) inhabiting Fukushima City located 70 km from the Fukushima Daiichi Nuclear Power Plant (NPP), and their health effect due to exposure to radioactive materials using the blood data. Cesium concentration in the muscle of monkeys was 6,000-25,000 Bq/kg in April 2011 and decreased over 3 months to around 1,000 Bq/kg. However, the concentration increased again to 2,000-3,000 Bq/kg for some individuals during winter period before returning to 1,000 Bq/kg in April 2012. In 2012, we carried out a one-year hematological study on a population of Fukushima City (n = 61) and the Shimokita Peninsula (n = 31) located approximately 400 km from the NPP as a control. Total muscle cesium concentration in Fukushima monkeys was in the range of 78-1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared to Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit. In Fukushima immature monkeys the white blood cell count showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.

　

The Pale Grass Blue Butterfly in Fukushima.

Joji Otaki, Atsuki Hiyama, Wataru Taira, Chiyo Nohara, Mayo Iwasaki, Seira Kinjo and Masaki Iwata,
University of the Ryukyus

To fully understand what has happened to organisms living in the radiation polluted areas, long-term monitoring of the biological impacts on organisms is required. We investigated spatial and temporal changes of the abnormality rate (AR) in both field-caught adult and laboratory-reared offspring populations of the pale grass blue butterfly, Zizeeria maha. They have generation time of approximately one month. We monitored 7 localities in and around Fukushima Prefecture every spring and fall over 3 years between 2011 and 2013 (n = 1,713 for field caught; n = 9,663 for offspring). The adult ARs peaked in the fall of 2011, while no AR increase was observed in non-contaminated localities. Among offspring, the total ARs, which include deaths at premature stages and morphological abnormalities at the adult, peaked either in the fall of 2011 or in the spring of 2012. The AR level was much higher than those of the parent field populations for those periods, suggesting that the similarly high level of deaths and abnormalities might have occurred also among the field populations. Importantly, the elevated ARs in the field and offspring came back to normal by the fall of 2012 and by the spring of 2013, respectively. These results demonstrate an occurrence and an accumulation of adverse physiological and genetic effects in early generations, followed by their decrease in AR and recovery to the normal. The study provides one of the most comprehensive records of biological dynamics after a nuclear accident available today.

　

Effects of Radioactive Contamination around Fukushima Daiichi on the Morphology and Genetics on Aphids.

Shin-ichi Akimoto and Izumi Yao
Graduate School of Agriculture, Hokkaido University

To evaluate the impact of fallout from the Fukushima Daiichi Nuclear Power Plant accident on organisms, the morphology and viability of the gall-forming aphid Tetraneura sorini were compared between a Fukushima population and seven populations from non-contaminated areas. The present study focused on first-instar gall formers derived from the first sexual reproduction after the accident. Of 164 first instars from T. sorini galls collected 32 km from Fukushima Daiichi in spring 2012, 13.2% exhibited morphological abnormalities, including 4 conspicuously malformed individuals (2.4%). In contrast, in the control populations, first instars with abnormal morphology accounted for 0.0-5.1% (on average, 3.8%). The incidence of abnormalities was significantly higher in Fukushima than in the control populations. We morphologically compared first instars of the first generation (hatching from eggs on the bark surface and inducing galls) with those of the second generation ("clones" of the first generation and produced parthenogenetically in the galls as larvae). Of 543 second-generation first instars in the Fukushima population, only 0.37% had abnormalities. This result suggests that radioactive contamination had deleterious effects on embryogenesis in eggs deposited on the bark surface, but a negligible influence on the second generation produced in closed galls. Analysis of samples collected in spring 2013 indicated that the viability and healthiness of the aphids were recovered compared to those in the 2012 samples. Thus, a reduced level of radiation may have led to the recovery of viability and healthiness of the Fukushima population.

　

Research on Breeding of Ural Owl Using Nest-Boxes in Fukushima.

Isao Nishiumi
National Museum of Nature and Science

Birds of prey are top level consumers in terrestrial ecosystems and are known to be less abundant with increasing levels of radiation around Chernobyl and Fukushima. Causes of the declining predators in radioactively contaminated areas are assumed to be both the ecological concentration of radioactive substances and reduced abundance of the prey. The Ural Owl Strix uralensis is one of the top predators in the forest of Fukushima, and is known as an opportunistic predator, namely opportunistically hunts any rodents, moles and/or small birds which is abundant and easy to catch in their territory. We can easily investigate the contents of their food by setting video cameras in the nest, by collecting the remnant of the nest after breeding (composed of the pellet of chicks) or even by directly collecting their food because they often keep the food in the nest during early stage of their nestling period. I set 81 nests in total: 42 nest-boxes in Iitate village as highly contaminated areas, where air radiation dose is from 0.8 to 4.0 μSv/h; 23 nests in Tsuchiyu-onsen as low contaminated areas of 0.2 to 0.3 μSv/h; and 16 nests in Aizu as control areas of 0.06 to 0.15 μSv/h. I will report the results of our on-going investigation on how much the breeding of predatory species is influenced by radiation exposure. Nest-boxes of Ural Owl would provide us with an excellent monitoring window to evaluate the effect of radiation to terrestrial ecosystem.

　

The Effects of Radiation for Non-Human Biota in Marine Environment since the Fukushima NPS Accident.

Tatsuo Aono
National Institute of Radiological Sciences

Monitoring and surveying of radioactivity in seawater, sediments and biota in the marine environment around the eastern Japan in the Pacific were carried out for understanding the dispersion of artificial radionuclides after the Fukushima Daiichi Nuclear Power Station (FD1NPS) accident. The Fukushima-derived radionuclides in the ocean were not only the release of the high level contaminated water from FD1NPS but also the deposition directly from atmosphere. The maximum of Cs-137 concentrations at the FD1NPS were about 70,000 Bq /L on March, 2011 and then the activity of Cs-137 in seawater had decreased gradually to 1-2 mBq /L in a few months after this accident, approaching the pre-accident levels. However, the Cs-137 activity variation in marine environment differed among seawater, sediments and marine biota. The monitoring was reported only on the gamma-emitting radionuclides iodine-131 and radioactive cesium (Cs-134 and Cs-137) in the marine environment after this accident. It is well known that marine biota concentrates elements in their organ. The observed artificial gamma emitter radionuclides include not only I and Cs but also Ag-110m in marine biota. It is necessary to clarify the effects of the Fukushima-derived radionuclides in marine biota off Fukushima. The aim of the study is to examine the temporal and spatial variation of radioactivity in marine biota after this accident. Studies on the effects of radiation on marine biota off Fukushima will be presented with some assessment models.

Studying Immunological Effects of Ionizing Radiation through Microbiome.

Tomoko Steen
Georgetown University

Since the nuclear power plant accidents of Chernobyl and of Fukushima, the main concern has been the biological effects of ionizing radiation on organisms including humans and wild animals resident in affected areas. It has been very difficult, however, to assess the actual short- and long-term effects of radiation on organisms accurately. Ionizing radiation is invisible, and the level of some isotope such as strontium cannot be assessed using a standard Geiger counter. Radioactive isotopes released by the nuclear accidents have long half-lives, thus they continue to expose organisms and accumulate in their bodies. Biological accumulation differs from simple physical assessments of isotopes and further complicates measurement of biological effects. In searching of a reliable tool to assess the health effects of radiation on organisms, I have been investigating the use of the microbial commensals found with every animal - the microbiome. Recent advances and sequencing cost reductions have significantly improved studies on microbiome composition. Recent studies clearly show that the composition of the gut microbiome changes to reflect an organisms’ health, age, and immune system status. In some cases, the use of microbiome as treatment of patients in the form of fecal transplant shows success. In this talk, I will discuss possibilities of using the gut microbiome to investigate minute effects of ionizing radiation on wild animals and potential use of the system to aid ecosystem recovery.