Abstract

Purpose

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan on March 11 2011, the surroundings became contaminated with radionuclides. To understand the possible biological effects after chronic low dose-rate radiation in contaminated areas of Fukushima, we assessed the effects in large Japanese field mice (Apodemus speciosus) by means of chromosome aberration analysis.

Materials and methods

We collected A. speciosus in five sites around Namie Town, Fukushima (contaminated areas) and in two sites in Hirosaki City, Aomori (control areas, 350 km north of FDNPP) from autumn 2011 to 2013. The number of mice captured and ambient dose-rates were as follows: high (n = 11, 10.1–30.0 µGy h⁻¹), moderate (n = 10, 5.7–15.6 µGy h⁻¹), low (n = 12, 0.23–1.14 µGy h⁻¹) and control (n = 20, 0.04–0.07 µGy h⁻¹). After spleen extraction from rodents, spleen cell culture was performed to obtain metaphase spreads. Chromosome aberrations were assessed on Giemsa-stained metaphase spreads.

Results

Although the mice in the contaminated areas were chronically exposed, there was no radiation-specific chromosome aberrations observed, such as dicentric chromosomes and rings. Some structural aberrations such as gaps and breaks were observed, and these frequencies decreased annually in mice from Namie Town.

Conclusion

These findings suggest that chromosome aberration analysis is useful to evaluate and monitor radiation effects in wild animals.

中文翻译：

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福岛浪江镇大型日本田鼠 (Apodemus speciosus) 染色体畸变评估

摘要

目的

2011 年 3 月 11 日日本福岛第一核电站 (FDNPP) 事故后，周围环境被放射性核素污染。为了了解福岛受污染地区慢性低剂量率辐射后可能产生的生物学效应，我们通过染色体畸变分析评估了大型日本田鼠（Apodemus speciosus ）的影响。

材料和方法

我们从 2011 年秋季到 2013 年在福岛浪江镇周围的五个地点（污染区）和青森市弘前市的两个地点（控制区，FDNPP 以北 350 公里）收集了A. speciosus 。捕获的小鼠数量和环境剂量率如下：高（n  = 11, 10.1–30.0 µGy h ^-1），中等（n  = 10, 5.7–15.6 µGy h ^-1），低（n  = 12, 0.23–1.14 µGy h ^-1）和控制 ( n  = 20, 0.04–0.07 µGy h ^-1 )。从啮齿动物中提取脾脏后，进行脾细胞培养以获得中期扩散。在吉姆萨染色的中期扩散上评估染色体畸变。

结果

尽管受污染地区的小鼠长期暴露在外，但没有观察到辐射特异性染色体畸变，例如双着丝粒染色体和环。观察到一些结构异常，例如间隙和断裂，并且这些频率在纳米江镇的小鼠中逐年下降。

结论

这些发现表明，染色体畸变分析可用于评估和监测野生动物的辐射效应。