四川省部分地区食品放射性核素^(137)Cs含量及所致居民剂量

Content of^(137)Cs of radionuclide in food in parts of Sichuan Province and the resulting dose to residents

目的 调查四川省5个市(州)食品中人工放射性核素^(137)Cs含量情况,以掌握四川省各方位人工放射性核素^(137)Cs在食品中的水平、分布和变动趋势。方法 2016—2022年在乐山市、阿坝州、宜宾市、绵阳市和广元市采集粮食、蔬菜、奶粉、茶叶和肉类5类共计742个食品样品,使用高纯锗(HPGe)γ能谱仪测量样品中放射性核素^(137)Cs的活度浓度。采用SPSS 21.0软件处理数据,检验检出率的差异和检验平均活度浓度的差异采用方差分析,以P<0.05为差异具有统计学意义。结果 共有133个样品检出人工放射性核素^(137)Cs,总检出率为17.9%,活度浓度范围为0.006~2.770 Bq/kg。不同年度(F=5.708,P=0.017)、不同样品种类(F=4.899,P=0.027)的检出率存在差异,但不同年度的平均活度浓度(F=0.510,P=0.110)差异不明显。在4个方位地区上,检出结果无明显规律。食物中人工放射性核素137Cs所致居民年待积有效剂量为1.70×10^(-3)mSv。结论 放射性核素^(137)Cs在环境中是客观存在的,但活度浓度水平很低,本次调查结果仅为典型范围(0.2~0.8 mSv)最大值的0.21%。该水平对居民健康效应的剂量影响可忽略不计。

Objective To investigate the content of^(137)Cs of radionuclide in food in five cities(prefectures)of Sichuan Province from 2016 to 2022,in order to grasp the level,distribution,and the trend of changes of artificial radioactive nuclides^(137)Cs in food from various directions in Sichuan Province.Methods A total of 742 food samples were collected from five categories of grain,vegetables,milk powder,tea and meat,and the activity concentration of the radionuclide^(137)Cs in the samples was measured by a high-purity germanium(HPGe)gamma spectrometer.SPSS 21.0 statistical software was used for processing,the detection rate and the average activity concentration ware analyzed by variance,and the difference P<0.05 was considered statistical significance.Results Artificial radioactive nuclides^(137)Cs were detected in 133 samples,the total detection rate was 17.9%,the activity concentration range was 0.006-2.77 Bq/kg.There were differences in detection rates among different years(F=5.708,P=0.017)and sample types(F=4.899,P=0.027),but there was no significant difference in average activity concentration among different years(F=0.510,P=0.110)There was no obvious pattern in the detection results in four directions.The annual accumulative effective dose of ^(137)Cs in food was 1.70×10^(-3)mSv.Conclusions Radioactive nuclide^(137)Cs objectively exist in the environment,but the activity concentration level is very low,the results of this research are only 0.21%of the maximum value of the typical range(0.2-0.8 mSv).The dose effect of this level on residents'health is negligible.