广西桂西北某退役铀矿山区周边食品放射性核素含量及所致居民剂量

Radionuclide contents in food collected from regions surrounding retired uranium mine in Northwest of Guangxi and their committed dose to public

目的通过检测广西壮族自治区桂西北某退役铀矿山区周边食品放射性核素含量,了解矿区周边食品放射性污染水平。方法2017-2018年,采集大米、红薯、黄豆共3种食品,用高纯锗γ能谱仪检测样品中的238U、226Ra、232Th、40K和137C的放射性核素的比活度。结果食品中除红薯中的226Ra含量超过标准限值以外,其余放射性核素含量均在标准限值以内;成年男子从大米、黄豆和红薯3类食品中摄入放射性核素所致年待积有效剂量为167.08μSv,仍属天然本底范围。结论食品中检出人工放射性核素137Cs,为大气中放射性核素沉降所致,238U、226Ra、232Th、40K含量偏高主要是由当地地质结构及周围环境所致,其水平不会对人体健康有影响。

Objective By detecting the radionuclide content of food around a retired uranium mine in the northwest of Guangxi Zhuang Autonomous Region,to understand the level of food radioactive pollution around the mine area.Methods From 2017-2018,samples of three kinds of food,including rice,sweet potato and soya bean,were collected and specific activity of238 U,226 Ra,232 Th,40 K and137 C were analyzed by using purity germanium(HPGe)gamma-ray spectrometry.Results The activity of226 Ra in sweet potato exceeded the standard limit,while the activity of other radionuclides met the standard limits.The total annual committed effective dose to adult man by the intake of radionuclides from rice,soybean and sweet potato was 167.08μSv,which was still within a natural background range.Conclusion The detected artificial radionuclide137 Cs in food is caused by the atmospheric radionuclide deposition,and the content of238 U,226 Ra,232 Th and40 K is relatively high,which is mainly caused by the local geological structure and the surrounding environment,and will not affect human health.