某铀矿区水体^(238)U和^(226)Ra污染源项特征及健康风险评价

Health Risk Assessment of U and Ra Water Sources in a Uranium Mine

为了解某铀矿区源项污染特征和对周边居民产生的潜在健康风险,采集场地污染源项水样,测试分析^(238) U和^(226) Ra活度浓度及有效剂量当量,采用箱线图及正态分布来分析其活度浓度分布特征,采用修正内梅罗法对研究区放射性核素和水质污染状况进行评价,对核素经饮水途径在不同年龄段(幼儿、儿童和成人)引起的健康风险进行评价。结果表明,研究区放射性核素^(238) U、^(226) Ra浓度均远超当地背景值,且^(238) U活度浓度高于^(226) Ra;矿井口水样放射性核素含量高于废石和工业场地,矿区水体受放射性核素污染严重;研究区贯穿辐射剂量对周边环境影响较小,核素致癌风险大小顺序为矿井口>工业场地>废石场地;放射性核素经饮水途径在不同年龄段引起的放射性风险敏感程度为幼儿>儿童>成人,其中幼儿终身致癌风险超过ICRP(国际辐射防护委员会)最大可接受风险值,儿童和成人超标率分别为85.7%、71.4%。

In order to understand pollution characteristics of source items in a uranium mining area and potential health risks to surrounding residents,water samples from pollution sources were collected,activity concentration and effective dose equivalent of ^(238) U and ^(226) Ra were tested and analyzed.The activity concentration distribution characteristics were analyzed by box line diagram and normal distribution.Radionuclide and water quality pollution status in the study area was evaluated by modified Nemero method,and health risks of radionuclide drinking water in different ages(infants,children and adults)were evaluated.The results show that concentrations of ^(238) U and ^(226) Ra in study area are far higher than the local background value,and activity concentration of ^(238) U is higher than that of^(226) Ra.Radionuclide content of mine entrance water is higher than that of waste rock and industrial site,and water body in mining area is seriously polluted by radionuclides.Penetrating radiation dose in study area has little impact on surrounding environment,and if sorted by impact size,the order of radionuclide carcinogenic risk is mine entrance>industrial site>waste rock.Sensitivity of radionuclides in different age groups is infants>children>adults.Lifetime cancer risk of children exceeds the maximum acceptable risk value of ICRP (International Commission on Radiation Protection).The exceeding rates of children and adults are 85.7%and 71.4%respectively.