某稀土冶炼厂及周边土壤放射性水平调查及风险评估  

Investigation and risk assessment of soil radioactivity levels at a rare earth refining factory and surrending area

作　　者：朱小铰 肖笔夫 谷洪[1] 吕映赋 刘佩[1] 周伟 李元东 唐辉 ZHU Xiaojiao;XIAO Bifu;GU Hong;LV Yingfu;LIU Pei;ZHOU Wei;LI Yuandong;TANG Hui(Sichuan Management and Monitoring Center Station of Radioactive Environmenth,Chengdu 611139;The College of Nuclear Technology and Automation Engineering,Chengdu University of Technology,Chengdu 610059)

机构地区：[1]四川省辐射环境管理监测中心站,成都611139 [2]成都理工大学核技术与自动化工程学院,成都610059

出　　处：《辐射防护》2024年第3期233-239,共7页Radiation Protection

基　　金：四川省生态环境保护科技项目计划——四川省铅锌矿放射性水平调查。

摘　　要：为查明某稀土冶炼厂及周边土壤放射性污染程度及危害,调查了该冶炼厂及周边土壤中^(238)U、^(232)Th、^(226)Ra在不同时期的质量活度浓度变化情况,采用地累积指数法、单因子污染指数与内梅罗综合污染指数法对土壤的放射性核素污染情况进行了评价,并用美国环保署(EPA)的健康风险评估模型开展了风险计算。结果表明^(238)U、^(232)Th、^(226)Ra 3种放射性核素的质量活度浓度范围分别为:20.9~92.6 Bq/kg、25.1~565.5 Bq/kg、17.3~83.1 Bq/kg;地累积指数法表明排放口下游、厂区西侧两个采样点为单核素污染;单因子污染指数与内梅罗综合污染指数法表明各点位土壤的综合污染均达到了轻度污染;健康风险评估表明该厂区^(238)U、^(232)Th、^(226)Ra导致的最大风险值均小于10^(-6),均在可接受范围内,主要暴露途径为摄入途径,其中最大风险来源于^(232)Th。调查结果表明该稀土冶炼厂及周边土壤中的^(238)U、^(232)Th、^(226)Ra对人体的健康风险在可接受范围内。In order to find out the range and harm of radioactive contamination in soil of a rare earth refining factory and its surrounding soil,the mass activity concentrations of ^(238)U,^(232)Th and ^(226)Ra in soil of a rare earth refining factory and its surrounding soil were investigated.The radionuclide contamination of soil in the study area was evaluated by geological accumulation index method,single factor pollution index method and Nemerow comprehensive pollution index method.The health risk assessment model of US EPA was used for risk calculation.The results showed that the mass activity concentration ranges of ^(238)U,^(232)Th and ^(226)Ra were 20.9-92.6 Bq/kg,25.1-565.5 Bq/kg,17.3-83.1 Bq/kg,respectively.The geological accumulation index method showed that the two sampling points downstream of the outlet and west side of the plant were mono-nuclide pollution.The single factor pollution index method and Nemerow comprehensive pollution index method showed that the comprehensive pollution of soil at each site reached mild pollution.Health risk assessment showed that the maximum risk values caused by ^(238)U,^(232)Th and ^(226)Ra were all less than 10^(-6),and all were within the acceptable range.The main exposure routes were ingestion routes,and the greatest risk came from ^(232)Th.The investigation shows that the health risk of ^(238)U,^(232)Th and ^(226)Ra in a rare earth refining factory and its surrounding soil is within the acceptable range.

关 键 词：土壤 放射性污染 放射性核素 风险评估 

分 类 号：X822.5[环境科学与工程—环境工程]