某化工厂土壤与地下水Cr^(6+)污染分布及健康风险  

Distribution and Health Risk Assessment of Cr^(6+)in Soil and Groundwater of a Chemical Plant

作　　者：马海珍 张振师[1] 李权[1] 许林 戈洋 杨贞 MA Haizhen;ZHANG Zhenshi;LI Quan;XU Lin;GE Yang;YANG Zhen(Northwest Engineering Corporation Limited,Xi'an 710054,Shaanxi,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,陕西西安710054

出　　处：《西北地质》2024年第1期73-82,共10页Northwestern Geology

基　　金：2021年度中央水污染防治专项项目(第一批)资助。

摘　　要：为掌握某化工厂Cr^(6+)污染状况及风险水平,在研究区布设土壤与地下水采样点各19个,测定Cr^(6+)含量,分析污染特征与成因,并开展健康风险评估。结果表明:表层土壤(0~0.5 m)Cr^(6+)超标率为42.11%,其浓度随深度增加总体上降低,但在地下水位附近(15~20 m)回升,主要因长期淋溶作用使污染物向下迁移至含水层位富集。浅层地下水Cr^(6+)超标率为73.68%,深层地下水超标率为37.50%。整体而言该区土壤和地下水Cr^(6+)污染形势不容乐观,应开展水土协同治理。空间上表层土壤Cr^(6+)分布受人类活动影响,与投产期厂内功能区的划分相关性较低。地下水Cr^(6+)受水动力场影响,表现为西北高东南低,污染羽中心向下游方向迁移。土壤致癌风险均值为1.85×10^(-6),介于10^(-6)~10^(-4),风险中等,应引起必要重视。非致癌风险低于1,无慢性毒害影响。经口摄入土壤为主要暴露途径。地下水致癌风险高达10-2数量级,远超过10^(-4),风险不可接受。非致癌风险均值51.62,远大于1,极可能引发慢性毒害效应。另外需进一步考虑Cr^(6+)通过牛羊肉食物链进入人体的危害。In order to clarify the Cr^(6+)pollution status and risk level of a chemical plant,19 soil and groundwater sampling points were laid in the study area,and the content of Cr^(6+)was measured,to analyze the pollution characteristics and causes,and to carry out health risk assessment.The results showed that the excess rate of Cr^(6+)in topsoil(0~0.5 m)was 42.11%.In general,the Cr^(6+)concentration in soil decreased with the increase of depth,but it rose up near the groundwater level(15~20 m),which was mainly due to the longterm leaching effect that the pollutants migrated down to the aquifer and enriched.The excess rate of Cr^(6+)in shallow and deep groundwater was 73.68%and 37.50%,respectively.Overall,the Cr^(6+)pollution is not optimistic,and comprehensive water-soil treatment should be carried out.At the spatial scale the distribution of Cr^(6+)in topsoil was affected by human activities,and had a low correlation with the division of functional zones.And under the influence of hydrody-namic field,Cr^(6+)in groundwater is higher in the northwest than the southeast,and the center of the pollution plume has migrated downstream.In addition,the mean value of soil carcinogenic risk is 1.85×10^(-6),which is between 10^(-6)and 10^(-4),and the risk is moderate,which should be paid more attention to.Soil non-carcinogenic risk is less than 1 and doesn’t produce chronic toxic effects.Oral ingestion of soil was the main exposure route.The carcinogenic risk of groundwater is up to the order of 10^(-2),much more than 10^(-4),which is unacceptable.The average non-carcinogenic risk is 51.62,much higher than 1,which may cause chronic toxic effects.In addition,the health hazards caused by Cr^(6+)entering the human body through the beef and mutton food chain should be further studied.

关 键 词：重金属 铬 污染特征 健康风险 

分 类 号：P641.12[天文地球—地质矿产勘探] X523[天文地球—地质学]