Abstract

Following the great East Japan earthquake, the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident happened 1–4 days later. In this proceedings, the author will introduce our experience, what we observed, and worked for recovering from this disaster. Apart from the initial radioactive iodine, the major source of radiation was radiocesium, namely ¹³⁴Cs and ¹³⁷Cs. Hopefully Strontium-90 was less than 1/1000 of radiocesium and was negligible. To present knowledge, apart from observation of abnormalities found in butterflies, fish, and birds, there is no report or observation on mammalian species that suffered from acute or chronic radiation effects. Those include chromosomal or DNA damage, anomaly, and/or radiation induced tumor or cancer in Fukushima. However, accidents will happen. But forewarned is forearmed. Prevention is better than the cure. VMAT (Veterinary Medical Assistant Team on disaster) was created and its guideline was proposed in Fukuoka (2012) and in Gunma (2016). They also started training veterinary experts. Therefore, you can never be too prepared before it starts.

Introduction

On 11th March 2011, the great East Japan earthquake (magnitude 9.0) happened followed by a gigantic Tsunami (wave height was over 10 m and the maximum run-up height was over 40 m) and the disaster caused by Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that happened 1–4 days later. In severely damaged areas, there was no electricity, no transport system, and/or no cars available simply because the roads were covered with mud, sea water, and rubble, cars with no drivers, and occasionally ships on the road. Moreover, many roads were cracking everywhere near FDNPP. In this series of the events over 15 thousand people were dead and about 91% of the cause was drowned by tsunami.

In this lecture the author would like to talk about the impact of nuclear accidents on animals and what we have seen and learned about Fukushima, especially focused on the eye from a veterinary radiologist working in the referral hospital and university; our experience and suggestive instruction from animal victims in the ex-evacuation zone since the disaster caused by FNPPF accident according to the following regime.

The purpose of this study is to explain the following successive issues:

• What happened soon after the FDNPP accident… escape from evacuation zone and refugee
• How to rescue animals; A proposal to the government from animal/radiology experts
• Problems and efforts for rescuing companion animals and creating animal shelters and their management
• Investigations of companion animal radiation exposure and cumulative radiobiological effects
• Investigations of farm animal radiation exposure and cumulative radiobiological effects
• Investigations of wild animals’ radiation exposure and cumulative radiobiological effects
• What we have learned from the nuclear accident and what should be done for the future prevention

Results and Discussion

Soon after the FDNPP accident, Fukushima local government declared to evacuate people within 2 km from FDNPP, followed by the Japanese government’s (JG)’s order to evacuate within 3 km. This was changed to 10 km later that night. The next morning JG declared a state of emergency… and finally, JG decided to create 20 km radius evacuation zone from FDNPP and people within 20–30 km radius should have to keep sheltering in each house instead of evacuating. But along the sea coast, roads and electricity were no longer useful, therefore, many people who succeeded in evacuating could not move to anywhere. Later in the FDNPP accident, the ground radioactivity was monitored from air flight and radioactivity monitoring cars, which were opened to the public for radioactivity-related information for initial evacuation.

IFAW: international fund for animal welfare immediately respond to this big event, calling Japanese and American veterinary, radiology, and evacuation/management experts to discuss and give tutorial information to support JG’s decision making for animal support. In the beginning of May 2011. They got together in Tokyo with observers from MAFF and MoE, with attendance of a politician. These committee members successfully did make a guidance supportive to the JG (Nuclear Accidents and the Impact on Animals committee recommendations) in two days. This was also sent to JG, media, including SNS, and politicians who may relate for this action. Hopefully, this could partially move JG to make it possible to start rescuing animals. However, in reality, only companion animal rescue was planned but farm animals were decided to be euthanize but only with the agreement of the owner farmers. Many farmers disagreed to kill them, since there is no clear reason.

Initial problems for animal rescue was there was no place or shelter, or prepared facility to accept animal refugees. This was one of the reasons the local government did not agree to start rescuing companion animals. In the meantime, with no action by local government, valuable animals (retrievers and/or qualified breeds, and puppies of breeders) were stolen and sold by someone. Or someone in fanatic or aggressive animal welfare organizations took the animals to their own shelters and charged relatively expensive fees for returning to the (original or) second owners. Such unwanted information also spread out through SNS. And some (personal) organization of animal welfare asked for fund raising to rescue animals through SNS, which created a scam or fake organization only to imitate animal welfare activities. Some aggressive animal welfare organization tried almost to thread local government by long time phone attacks.

However, an animal shelter in temporary use was created in June and voluntary staff to manage or support were asked to join. A voluntary staff, especially a famous actress, temporarily helping, worked effectively since it soon spread through SNS. Companion animal rescue has just started on the opening day of the temporary shelter. However, the rescuing had to stop by the first day, which was simply due to the very limited capacity of the shelter to accept them. Alternatively, this was because owners of companion animals could not take them for evacuation. This very severe experience moved the ministry to alter the law. The refugee principally should evacuate with their pets together and each local government should prepare for that.

Wada et al. (2017) has monitored radioactivity of animal refugees in a shelter in Fukushima frequently by animal whole-body counter. Concentration of ¹³⁷Cs at the time they were caught was in the range of 10 to 10⁷ Bq/kg in dogs and 10³ to 10⁶ Bq/kg in cats. And they concluded the biological average half-life of radiocesium was 54 days in dogs and 30 days in cats, and they discovered their biological half-lives prolongs from 20 to 70 days as they grew up. This whole-body counting system for small animal sounds valuable for long-term monitoring of radioactivity in the body and most likely applicable to other small animals including sheep, goats, and other wildlife.

Teams from the veterinary universities including Iwate, Kitasato, Tokyo, and Miyazaki joined to collaborate and investigate if there is/are any biological effects of the low-dose radiation. This team tried to evaluate radiation exposure from environmental and internal exposure via ingestion of grass. Since hundreds of cattle within 20 km from FDNPP are kept alive because these farmers disagreed to the JG’s decision to euthanize without any reasonable explanation. Farmers needed to know if there is/are any unwanted biological effects of the low dose radiation on cattle. Some cattle showed some white spot. The teams also evaluated routine blood tests, ambient radiation dose rate, radioisotope analyses from biological samples and soils in the farm where cattle are kept.

The cumulative radiation dose in the farm was estimated at most 1.2 to 1.5 Gy (or Sv for human effective dose) for 7 years since the FDNPP accident happened. However, blood tests and biochemistry from cattle was in the normal range and showed no abnormality. Comet assay to detect some degree of DNA degradation.

Sasaki et al. reported that the major sickness or abnormality was sporadically observed. The major cattle diseases or abnormalities found in the evacuation zone was nine cases (3.7%) of enzootic bovine leukosis (EBL) and three cases (1.2%) of goiter were diagnosed. Estimated integrating dose of external exposure in EBL cases ranged from a maximum of 1200 mSv to a minimum of 72 mSv. There was no evidence of a radiation effect on pathological findings in any of these autopsy cases. This is ironic, since they were kept outside so long, most of them are now positive for bovine leukemia virus infection and found sick or dead due to the onset of leukemia. Geographic distribution of the soil contamination, ambient radiation dose rate and its time course will be also discussed.

Some investigations on wild animals were performed in non-mammalian species including monkeys, wild boars, fish, insects, and plants. The initial observation demonstrated that there was a decrease of white and red blood cells in the blood of monkeys to some extent, but so far extended decrease of the blood cell is not reported.

• What happened soon after the FDNPP accident… escape from evacuation zone and refugee
• How to rescue animals; A proposal to the government from animal/radiology experts
• Problems and efforts for rescuing companion animals and creating animal shelters and their management
• Investigations of companion animal radiation exposure and cumulative radiobiological effects
• Investigations of farm animal radiation exposure and cumulative radiobiological effects
• Investigations of wild animals’ radiation exposure and cumulative radiobiological effects
• What we have learned from the nuclear accident and what should be done for the future prevention

Apart from the initial radioactive iodine, the major source of radiation was radiocesium, namely ¹³⁴Cs and ¹³⁷Cs. Hopefully Strontium-90 was less than 1/1000 of radiocesium and was negligible. To present knowledge, apart from observation of abnormalities found in pale grass blue butterflies, fish, and birds, there is no report or observation on mammalian species who suffered from acute or chronic radiation effects. Those include chromosomal or DNA damage, anomaly, and/or radiation induced tumor or cancer in Fukushima. However, accidents will happen. But forewarned is forearmed.

Prevention is better than the cure. VMAT (Veterinary Medical Assistant Team on disaster) was created and its guideline was proposed in Fukuoka (2012) and in Gunma (2016). They also started training veterinary experts. Therefore, you can never be too prepared before it starts. Concerning preparation of shelters and or VMAT, periodic intimate communications (and simulative trainings, if possible) are inevitable to keep good contact among veterinarians, assistants, support staff for local government, and volunteers.

References

1.  A committee of subject matter experts from Japan and the United States. Nuclear accidents and the impact on animals: Committee recommendations. May 2–3, 2011. https://s3.amazonaws.com/ifaw-pantheon/sites/default/files/legacy/IFAW-nuclear-accidents-impact-animals-decontamination-2014.pdf.

2.  Wada S, Ito N, Watanabe M, et al. Whole-body counter evaluation of internal radioactive cesium in dogs and cats exposed to the Fukushima nuclear disaster. PLoS One. 2017;12(1):e0169365. doi:10.1371/journal.pone.0169365.

3.  Sasaki J, Hiratani K, Sato I, et al. Pathological findings of Japanese black cattle living in the restricted area of the Fukushima Daiichi nuclear power plant accident 2013–2016. Anim Sci J. 2017;88(2):2084–2089.

4.  Ochiai K, Hayama S, Nakiri S, et al. Low blood cell counts in wild Japanese monkeys after the Fukushima Daiichi nuclear disaster. Sci Rep. 2014;4:5793.

5.  Hiyama A, Nohara C, Kinjo S, et al. The biological impacts of the Fukushima nuclear accident on the pale grass blue butterfly. Sci Rep. 2012;2:570.

6.  Hiyama A, Nohara C, Taira W, Kinjo S, Iwata M, Otaki JM. The Fukushima nuclear accident and the pale grass blue butterfly: evaluating biological effects of long-term low-dose exposures. BMC Evol Biol. 201313:168.

7.  Nohara C, Hiyama A, Taira W, Tanahara A, Otaki JM. The biological impacts of ingested radioactive materials on the pale grass blue butterfly. Sci Rep. 2014;4:4946.

8.  Taira W, Hiyama A, Nohara C, Sakauchi Ko, Otaki JM. Ingestional and transgenerational effects of the Fukushima nuclear accident on the pale grass blue butterfly. J Radiat Res. 2015 Dec;56 Suppl 1:i2–18. doi: 10.1093/jrr/rrv068.