Southern Zhejiang Water Research Institute, Zhejiang Provincial Key Laboratory of Watershed Science and Health, Wenzhou Medical University, Wenzhou, 325035, China.
Zhijiang College of Zhejiang University of Technology, Shaoxing, 312030, China.
Environ Pollut. 2019 Feb;245:1022-1030. doi: 10.1016/j.envpol.2018.11.078. Epub 2018 Nov 28.
Metal contamination in aquatic environments is a severe global concern to human health and aquatic ecosystems. This study used several risk assessment indices, to evaluate metal (Cu, Zn, Pb, Cd and Cr) environmental risk of riverine surface sediments across the rural-urban interface of the rapidly developing Wen-Rui Tang River watershed in eastern China. Risk assessments were determined for 38 sites based on the potential ecological risk index (RI), consensus-based sediment quality guidelines (SQGs) and risk assessment code (RAC). Land-use cluster analysis showed that sediments were severely contaminated, especially for Cd, whose concentrations were ∼100 times higher than background levels and had a high proportion in the bioaccessible fraction. According to RI, E was identified with extremely high risk potential, resulting in the highest ecological risk of Cluster 4 (industrial). Similarly, risk within Cluster 4 (industrial) was also ranked highest by SQGs assessment due to the high proportion of industrial land use. Zinc was determined with high risk due to its high concentration compared to its effect range medium (ERM) value. Discrepancies in predicting environmental risks from metals among the three indices were mainly attributed to the contrasting definitions of these metrics. Environmental risk uncertainty derived from spatial variation was further estimated by Monte Carlo simulation and ranked as: Zn > Cd > Cr > Pb > Cu. This comprehensive environmental risk assessment provides important information to guide remediation strategies for management of metal contamination at the watershed scale.
金属污染物在水生环境中对人类健康和水生生态系统构成了严重的全球性威胁。本研究采用了多种风险评估指标，对中国东部快速发展的温瑞塘河流域城乡交错带河流水体表层沉积物中的金属（Cu、Zn、Pb、Cd 和 Cr）环境风险进行了评估。基于潜在生态风险指数（RI）、基于共识的沉积物质量基准（SQGs）和风险评估准则（RAC），对 38 个采样点进行了风险评估。土地利用聚类分析表明，沉积物受到了严重的污染，尤其是 Cd 的污染，其浓度是背景值的约 100 倍，且具有较高的生物可利用分数。根据 RI，E 被认为具有极高的潜在风险，导致了工业用地为主的第 4 类（工业）的最高生态风险。同样，基于 SQGs 评估，由于工业用地比例较高，第 4 类（工业）的风险也被评为最高。由于其浓度高于效应范围中值（ERM）值，Zn 被确定为高风险。这三种指标对金属环境风险的预测存在差异，主要归因于这些指标定义的差异。通过蒙特卡罗模拟进一步评估了空间变化引起的环境风险不确定性，并按以下顺序进行了排序：Zn > Cd > Cr > Pb > Cu。这项综合环境风险评估为流域尺度上金属污染管理的修复策略提供了重要信息。
