Evaluation of DNA damage and stress in wildlife chronically exposed to low-dose, low-dose rate radiation from the Fukushima Dai-ichi Nuclear Power Plant accident. (October 2021)

• Record Type: Journal Article
• Authors: Cunningham, Kelly; Hinton, Thomas G.; Luxton, Jared J.; Bordman, Aryn; Okuda, Kei; Taylor, Lynn E.; Hayes, Josh; Gerke, Hannah C.; Chinn, Sarah M.; Anderson, Donovan; Laudenslager, Mark L.; Takase, Tsugiko; Nemoto, Yui; Ishiniwa, Hiroko; Beasley, James C.; Bailey, Susan M.
• Is Part Of: Environment international. Volume 155(2021)
• Publication Date: 2021-10
• Subjects: Cortisol -- Telomeres -- Dicentric chromosomes -- Low-dose -- Low-dose rate radiation -- Fukushima; BD Becton Dickinson -- Bq Becquerel -- DNA Deoxyribonucleic acid molecule -- EIA Enzyme Immunoassay -- ERICA Environmental risks from ionising contaminants: assessment and management -- FEZ Fukushima Exclusion Zone -- FISH Fluorescence in situ Hybridization -- GAMs generalized additive models -- Gy gray -- K2-EDTA dipotassium ethylenediaminetetraacetic acid -- LD-LDR low dose-low dose rate -- LED light-emitting diode -- MEXT Ministry of Education, Culture, Sports, Science and Technology -- mGy milli-gray -- MTL Mean telomere length -- NaI(Tl) Sodium-iodide (thallium) -- OSL optically stimulated luminescence -- PMA Phorbol myristate acetate -- qPCR quantitative Polymerase Chain Reaction -- RPMI-1640 Roswell Park Memorial Institute 1640 cell medium -- sCMOS scientific complementary metal oxide semiconductor -- TC-FISH Telomere-Centromere Fluorescence in situ Hybridization -- µGy micro-gray; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2021.106675
• Languages: English
• ISSNs: 0160-4120

Abstract

Graphical abstract: Highlights: Wildlife remained in areas evacuated by humans after the Fukushima nuclear accident. Wild boar and snakes were studied in Japan's most radioactively contaminated areas. Biomarkers of DNA damage (dicentrics) and stress (telomeres, cortisol) were studied. Comprehensive dosimetry was conducted for chronically exposed free-ranging animals. No harmful effects were detected from the low dose, low dose rate exposures. Abstract: The health effects associated with chronic low-dose, low-dose rate (LD-LDR) exposures to environmental radiation are uncertain. All dose-effect studies conducted outside controlled laboratory conditions are challenged by inherent complexities of ecological systems and difficulties quantifying dose to free-ranging organisms in natural environments. Consequently, the effects of chronic LD-LDR radiation exposures on wildlife health remain poorly understood and much debated. Here, samples from wild boar ( Sus scrofa leucomystax ) and rat snakes ( Elaphe spp.) were collected between 2016 and 2018 across a gradient of radiation exposures in Fukushima, Japan. In vivo biomarkers of DNA damage and stress were evaluated as a function of multiple measurements of radiation dose. Specifically, we assessed frequencies of dicentric chromosomes (Telomere-Centromere Fluorescence in situ Hybridization: TC-FISH), telomere length (Telo-FISH, qPCR), and cortisol hormone levels (Enzyme Immunoassay: EIA) in wild boar, and telomere length (qPCR) in snakes. These biological parameters were then correlated to robust calculations of radiation dose rate at the time of capture and plausible upper bound lifetime dose, both of which incorporated internal and external dose. No significant relationships were observed between dicentric chromosome frequencies or telomere length and dose rate at capture or lifetime dose (p value range: 0.20–0.97). Radiation exposure significantly associated only with cortisol, where lower concentrations were associated with higher dose rates (r 2 = 0.58; p < 0.0001), a relationship that was likely due to other (unmeasured) factors. Our results suggest that wild boar and snakes chronically exposed to LD-LDR radiation sufficient to prohibit human occupancy were not experiencing significant adverse health effects as assessed by biomarkers of DNA damage and stress.