Analysis of Radioactive Elements in Testes of Large Japanese Field Mice Using an Electron Probe Micro-Analyser after the Fukushima Accident

Abstract

The Fukushima Daiichi nuclear power plant (FDNPP) accident drew global attention to the health risks of radiation exposure. The large Japanese field mice (Apodemus speciosus) are rodents endemic to, and distributed throughout, Japan. This wild rodent live in and around the ex-evacuation zone on the ground surface and/or underground. In this study, we evaluated the effect of chronic radiation exposure associated with FDNPP accident on the testes of large Japanese field mice. Morphological analysis and electron-prove X-ray microanalysis (EPMA) was undertaken on the testes. Morphological analysis of testes based on H&E staining showed that the spermatogenesis was observed normally in the breeding season of wild mice in the heavily contaminated area. However, caesium (Cs) was not detected in all testes of wild mice from FDNPP ex-evacuation zone. In conclusion, even if the testes and the process of spermatogenesis are hypersensitive to radiation, we could not detect radiation effects on the spermatogenesis and Cs in the examined large Japanese field mice testes following chronic radiation exposure associated with the FDNPP accident.

Morphological reproductive characteristics of testes and fertilization capacity of cryopreserved sperm after the Fukushima accident in raccoon (Procyon lotor)

“…Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, large amounts of radioactive substances, particularly volatile elements, such as radioactive iodine, caesium and tellurium, were released into the environment. The ex‐evacuation zone comprises a 20‐km‐radius area around the FDNPP, from which we have established an archive system of livestock and wild animals (Ariyoshi et al., 2018; Fukuda et al., 2013; Fukuda et al., 2015; Fukuda et al., 2016; Koarai et al., 2016; Koarai et al., 2018; Koarai et al, 2020; Ohdaira et al., 2019; Suzuki et al, 2020; Takahashi et al., 2015; Takino et al., 2017; Urushihara et al., 2016; Meguro et al., 2019; Urushihara et al., 2018; Yamashiro et al., 2013; Yamashiro et al., 2014; Yamashiro et al., 2015).…”