Wang Hui-Man, Ge Qin, Wei Chao, Li Xiang, Liu Hai-Yan, Li Xin-Yan
School of Water Resources & Environmental Engineering, East China University of Technology, Nanchang 330013, China.
Jiangxi Province Key Laboratory of the Causes and Remediation of Groundwater Pollution, Nanchang 330013, China.
Huan Jing Ke Xue. 2025 Jun 8;46(6):3429-3439. doi: 10.13227/j.hjkx.202405145.
Groundwater metal elements pollution is one of the most serious environmental problems in the tailings area. Identifying its distribution characteristics and sources provides data and methodological support for precise prevention and control of groundwater pollution. Spatial distribution characteristics of nine metal elements （Al， Zn， Cu， Mn， Pb， Cd， Fe， Ba， and As） in groundwater were revealed using descriptive statistics and kriging interpolation. A comprehensive evaluation of groundwater quality was conducted using a random forest model. Combined with correlation analysis， principal component analysis-multiple linear regression model， and Monte Carlo simulation， the sources of metal element pollution were quantitatively analyzed， and health risks were assessed for specific sources. The results showed that： ① In some areas， the levels of Al， Mn， Pb， Fe， Ba， and As in groundwater exceeded the Class III standards of the Groundwater Quality Standards. The exceedance rates from highest to lowest were： Mn （60.94%） = Fe （60.94%） > Al （46.88%） > As （6.25%） > Pb （4.69%） > Ba （3.13%）. ② Evaluation using the random forest model indicated that groundwater quality in the study area mainly fell within Classes II to IV， reflecting generally poor water quality. Key indicators affecting groundwater quality levels were Al， Pb， Fe， and Mn， with higher concentrations observed in the central > southern > northern parts. ③ The primary sources of groundwater metal element pollution included geological background， industrial activities， agricultural activities， traffic emissions， and tailings slag. Among these sources， tailings slag contributed the most （37%） to the accumulation of metal elements in groundwater. ④ Monte Carlo simulation results highlighted carcinogenic health risks for adults and both carcinogenic and non-carcinogenic risks for children due to groundwater metal elements. ⑤ Tailings slag was identified as the main contributor to carcinogenic risks （38.5%）， with Cd being the major contributor. On the other hand， geological background and industrial activities were the primary contributors to non-carcinogenic risks （40.6%）， primarily due to Al， Mn， and As. Therefore， significant attention is required to address groundwater environmental pollution issues in tailings areas.
尾矿库区域地下水金属元素污染是最为严重的环境问题之一。识别其分布特征与来源可为地下水污染精准防控提供数据和方法支持。运用描述性统计和克里金插值法揭示了地下水中9种金属元素（铝、锌、铜、锰、铅、镉、铁、钡和砷）的空间分布特征。采用随机森林模型对地下水质量进行综合评价。结合相关性分析、主成分分析 - 多元线性回归模型以及蒙特卡罗模拟，对金属元素污染来源进行定量分析，并针对特定来源评估健康风险。结果表明：①部分区域地下水中铝、锰、铅、铁、钡和砷含量超过《地下水质量标准》Ⅲ类标准。超标率由高到低依次为：锰（60.94%） = 铁（60.94%）＞铝（46.88%）＞砷（6.25%）＞铅（4.69%）＞钡（3.13%）。②随机森林模型评价表明，研究区地下水质量主要处于Ⅱ - Ⅳ类，整体水质较差。影响地下水质量等级的关键指标为铝、铅、铁和锰，中部＞南部＞北部含量较高。③地下水金属元素污染的主要来源包括地质背景、工业活动、农业活动、交通排放和尾矿渣。其中，尾矿渣对地下水中金属元素累积贡献最大（37%）。④蒙特卡罗模拟结果显示，地下水金属元素对成人存在致癌健康风险，对儿童则同时存在致癌和非致癌风险。⑤尾矿渣被确定为致癌风险的主要贡献者（38.5%），镉为主要贡献元素。另一方面，地质背景和工业活动是非致癌风险的主要贡献者（40.6%），主要源于铝、锰和砷。因此，尾矿库区域的地下水环境污染问题需引起高度重视。
