SREL Reprint #3671

Radiocesium accumulation and germline mutations in chronically exposed wild boar from Fukushima, with radiation doses to human consumers of contaminated meat

Donovan Anderson1,2, Shingo Kaneko3, Amber Harshman4, Kei Okuda5, Toshihito Takagi3,
Sarah Chinn6, James C. Beasley6, Kenji Nanba7, Hiroko Ishiniwa7, and Thomas G. Hinton7,8

1Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Aomori, Japan
2Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba,
Tsukuba, Ibaraki, Japan
3Symbiotic Systems Science and Technology, Fukushima University, Fukushima City, Fukushima, Japan
4Environmental Protection Services Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
5Faculty of Human Environmental Studies, Hiroshima Shudo University, Hiroshima, Japan
6Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources,
University of Georgia, Aiken, SC, USA
7Institute of Environmental Radioactivity, Fukushima University, Fukushima City, Fukushima, Japan
8Centre for Environmental Radioactivity, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway

Abstract: Genetic effects and radioactive contamination of large mammals, including wild boar (Sus scrofa), have been studied in Japan because of dispersal of radionuclides from the Fukushima Dai-ichi Nuclear Power Plant in 2011. Such studies have generally demonstrated a declining trend in measured radiocesium body burdens in wildlife. Estimating radiation exposure to wildlife is important to understand possible long-term impacts. Here, radiation exposure was evaluated in 307 wild boar inhabiting radioactively contaminated areas (50–8000 kBq m-2) in Fukushima Prefecture from 2016 to 2019, and genetic markers were examined to assess possible germline mutations caused by chronic radiation exposures to several generations of wild boar. Internal Cs activity concentrations in boar remained high in areas near the power plant with the highest concentration of 54 kBq kg-1 measured in 2019. Total dose rates to wild boar ranged from 0.02 to 36 µGy h-1, which was primarily attributed to external radiation exposure, and dose rates to the maximally exposed animals were above the generic noeffects benchmark of 10 µGy h-1. Using the estimated age of each animal, lifetime radiation doses ranged from <0.1 mGy to 700 mGy. Despite chronic exposures, the genetic analyses showed no significant accumulation of mutation events. Because wild boar is an occasional human dietary item in Japan, effective dose to humans from ingesting contaminated wild boar meat was calculated. Hypothetical consumption of contaminated wild boar meat from radioactively contaminated areas in Fukushima, at the per capita pork consumption rate (12.9 kg y-1), would result in an average effective annual dose of 0.9 mSv y-1, which is below the annual ingestion limit of 1 mSv y-1. Additionally, a consumption rate of about 1.4 kg y-1 of the most contaminated meat in this study would not exceed annual ingestion limits.

Keywords: Radiation dose, Ingestion, Mutation, Uptake, Wild boar, Fukushima

SREL Reprint #3671

Anderson, D., S. Kaneko, A. Harshman, K. Okuda, T. Takagi, S. Chinn, J. C. Beasley, K. Nanba, H. Ishiniwa, and T. G. Hinton. 2022. Radiocesium accumulation and germline mutations in chronically exposed wild boar from Fukushima, with radiation doses to human consumers of contaminated meat. Environmental Pollution 306(2022): 119359.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).