Risk assessment and source identification of multi-pollutants are essential for accurate control of soil contamination. However, complexity in pollutant properties and diversity in source types raise challenges to the target. Therefore, this study constructed a hierarchical ecological risk quantification method combined with risk ranking, risk of single pollutant using potential affected fraction (PAF), and joint risk of multi-pollutants employing msPAF. Taking regional contamination in South China as a case, the risk ranking was determined, while single and joint effects showed msPAF reaching 79.4 %, with risk as heavy metals (HMs) > per- and polyfluoroalkyl substances (PFASs) > polycyclic aromatic hydrocarbons (PAHs). Meanwhile, an integrated source apportionment method was established from three layers by principal component analysis to classify source types, multiple linear regression of distance to identify key sources, and positive matrix factorization to track omitted sources. Consequently, key sources were captured, with 80.8 %−93.2 % contribution of farmland and electroplating to three main HMs, 52.2 %−69.4 % contribution of roads to three main PAHs, and 71.1 %−73.2 % contribution of electroplating to two main PFASs. Further, omitted sources were tracked with contribution of 31.2 %−84.1 % to eight pollutants. The established methods can identify control targets, including high-risk pollutants and their key sources.

中文翻译：

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多污染物复合污染区应优先控制哪些污染物和来源？


多污染物风险评估和来源识别对于土壤污染的精准控制至关重要。然而，污染物性质的复杂性和来源类型的多样性给目标带来了挑战。因此，本研究构建了结合风险排序、单一污染物使用潜在受影响分数（PAF）的风险以及使用msPAF的多污染物联合风险的分层生态风险量化方法。以华南区域污染为例，确定风险排序，单效应和联合效应均显示msPAF达到79.4%，风险为重金属(HMs)>全氟烷基物质(PFASs)>多环芳烃（多环芳烃）。同时，通过主成分分析对源类型进行分类，通过距离多元线性回归识别关键源，通过正矩阵分解跟踪遗漏源，从三层建立了综合源解析方法。因此，捕获了关键来源，农田和电镀对三种主要 HMs 的贡献率为 80.8%−93.2%，道路对三种主要 PAHs 的贡献率为 52.2%−69.4%，电镀对两种主要 PFAS 的贡献率为 71.1%−73.2%。此外，追踪到的遗漏来源对八种污染物的贡献率为 31.2%−84.1%。所建立的方法可以识别控制目标，包括高风险污染物及其关键来源。