华北典型区域地下水重金属来源解析及健康风险识别

Source Apportionment and Health Risk Identification of Heavy Metals in Groundwater for Typical District in North China

科学评估地下水重金属健康风险并识别主要风险因子,对保障地下饮用水安全和开展地下水风险管控具有重要意义。选取华北典型区域地下水作为研究对象,根据地势和地下水流向选定了14个采样点,于2017—2019年采集了122个地下水样品,并对样品中的Cr6+、Cd、As、Mn、Fe、Cu、Hg、Pb、Se和Zn进行了检测,以多元统计分析和健康风险评价模型相结合的方式,明晰了地下水重金属的来源和主要风险因子。结果表明:①研究区域地下水中重金属的浓度均值排序为ρ(Fe)>ρ(Zn)>ρ(Mn)>ρ(As)>ρ(Se)>ρ(Cu),其余元素未检出。根据综合污染评价结果,研究区地下水水质整体较好。②就空间分布而言,S12采样点处的As(5.04μg/L)、Mn(4.36μg/L)、Fe(18.52μg/L)和Cu(0.38μg/L)浓度最高,Se在S5采样点(0.52μg/L)处浓度最高,Zn在S4采样点(12.88μg/L)处浓度最高。③多元统计分析结果显示,As、Cu、Fe和Mn可能来源于工业活动,Se可能来源于地质环境。④健康风险评价结果显示,儿童面临的风险高于成人,饮水是主要的重金属暴露途径,潜在风险主要来源于As。为保障居民地下饮用水安全,应当将As作为今后加强地下水保护的优先控制指标。

It is of great significance for groundwater drinking safety and risk control to scientifically evaluate the health risks of heavy metals in groundwater and identify the main risk factors.14 sampling sites in a typical region of North China were selected as the research object according to the topography and flow direction of groundwater.From 2017 to 2019,122 groundwater samples were collected and Cr6+,Cd,As,Mn,Fe,Cu,Hg,Pb,Se and Zn in the samples were analyzed.The sources and risk factors of heavy metals in groundwater were clarified by combining multivariate statistical analysis with health risk assessment model.The results showed that:①The mean concentration of heavy metals in groundwater in the study area wasρ(Fe)>ρ(Zn)>ρ(Mn)>ρ(As)>ρ(Se)>ρ(Cu),and the other elements were not detected.According to the comprehensive pollution assessment,the overall quality of groundwater was good.②In terms of spatial distribution,the concentrations of As(5.04μg/L),Mn(4.36μg/L),Fe(18.52μg/L)and Cu(0.38μg/L)were the highest at S12,Se was the highest at S5(0.52μg/L),the highest concentration of Zn was at S4(12.88μg/L).③Multivariate statistical results showed that the sources of As,Cu,Fe and Mn might come from industrial activities probably,and the source of Se might be geological origin.④The results of health risk assessment showed that children were at the higher risk than adults,drinking water was the main way of heavy metal exposure,and the main potential risk came from As.In order to ensure the drinking safety of groundwater,As should be taken as the priority control index to strengthen groundwater protection in the future.