福泉市磷矿开采聚集区地下水优先控制污染物的筛选及健康风险评估

Determination of Priority Control Pollutants and Health Risk Assessment of Groundwater in the Phosphate Mine Centralized Area in Fuquan City

福泉市是贵州省磷矿资源集聚区,也是重要的磷化工产业基地。磷矿开采产生的污染物造成区域地下水总磷(TP)、F~-、SO_(4)^(2-)及重金属污染,对影响区人群健康产生威胁。针对福泉市磷矿开采聚集区,采集代表性地下水样品,基于pH值、主要离子、重金属和有机物共计40项指标的检测结果,在地下水水质评价的基础上,通过潜在危害指数法和综合评分法确定了研究区地下水中优先控制污染物,分析了主要污染源,并利用健康风险评价模型评估了研究区地下水污染对人体产生的健康风险。结果表明:福泉市磷矿开采聚集区及周边地下水中TP、NH~+_(4)、SO_(4)^(2-)、CN~-、I~-、Pb、Mn、Sb和Ni等污染较突出,20%以上监测点地下水含量超过地下水Ⅲ类标准;其中地下水中TP与SO_(4)^(2-)、Ni、F~-、Al和Pb含量之间呈显著相关性,表明其具有同源性,地下水环境受磷矿开采等工业活动的影响明显;研究区地下水中优先控制污染物为F~-、Fe、Mn、Hg、Ni、Sb、As、Pb和Cd,人体健康风险评价显示,经饮水摄入途径造成的人群健康风险高于皮肤接触摄入途径,且儿童健康风险高于成人;不同评价单元健康风险排序为南部磷矿区>中部>北部;非致癌健康风险主要由F~-、As和Mn引起,As暴露通过饮水摄入途径和皮肤接触摄入途径以及Cd经饮水摄入途径的暴露人群致癌健康风险均高于最大可接受风险值。该研究结果可为区域地下水污染防控及供水安全提供依据。

Fuquan City is not only a concentrated area of phosphate mine resource in Guizhou Province,but also an important phosphate chemical industry base.Groundwater pollution of total phosphorus(TP),fluoride(F^(-)) and sulfate(SO_(4)^(2-)) were caused by phosphorus mining,which threatens the health of residents.In this paper,the representative groundwater samples were collected in the affected area of phosphate mine in Fuquan City.Based on the hydrochemical parameters,including pH,major ions,heavy metals and organic compounds,water quality evaluation and pollution source analysis were carried out.The priority control pollutants were determined using the method of potential hazard index and the comprehensive scoring.The health risk of groundwater pollution was evaluated,which provided basis for regional groundwater pollution prevention and control and water supply safety.The results show that the pollution of microorganism,TP、NH^(+)_(4)、SO_(4)^(2-)、CN^(-)、I^(-)、Pb、Mn、Sb and Ni in groundwater around phosphate mining area occurred obviously,and more than 20% of groundwater samples exceeded the grade of groundwater Ⅲ.TP is significantly correlated with SO_(4)^(2-)、Ni、F^(-)、Al、Pb,indicating their sources.Industrial activities such as phosphate mining have obvious influence on groundwater environment.The priority control pollutants in the study area are F^(-)、Fe、Mn、Hg、Ni、Sb、As、Pb、Cd,and human health risk assessments show that the health risk caused by drinking water exposure is higher than that caused by skin contact,and the health risk of children is higher than that of adults.The health risks of different evaluation units are ranked as follows:southern phosphorus mining area>central area>northern area.Non-carcinogenic health risks are mainly caused by F^(-),As and Mn,and the carcinogenic risks of exposed people through the two pathways of As,and Cd through drinking water are higher than the maximum acceptable risk value.