Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan 650500, China.
Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan 650500, China.
Sci Total Environ. 2022 Oct 15;843:157031. doi: 10.1016/j.scitotenv.2022.157031. Epub 2022 Jul 2.
Toxic trace elements represent an ongoing environmental problem in aquatic ecosystems. However, a lack of quantitative analysis and accurate evaluation has led to unguided control and water management strategies. Lake Yangzong is the main freshwater resource for nearly one million people in Yunnan Province in southwestern China. It has been heavily contaminated in recent years by significant anthropogenic activities including an industrial phosphor-gypsum spill, sewage effluent, and chemical remediation processes. Herein, we combine eco-environmental indices with multiple statistical analyses to determine the ecological risk and degree of contamination of 11 toxic trace elements in the upper sediments of the lakebed. Local geochemical background concentrations were determined using robust regression models developed from sediment core data. Pollution indices (EF/PLI) indicate that severe As contamination was centralized in the southwestern part of the lake. Other toxic trace elements (e.g., Cd, Cu, Pb) are slightly to moderately enriched, and progressively decrease from the northwestern to the southeastern areas of the lake. A more accurate and sensitive index (PCR) was proposed herein, suggesting that contamination was dominated by As and Pb in different lake sections. The northern section of the lake and the southwestern bay exhibited higher contaminant levels than other regions of the lake. Bio-toxic indices (ERF/PERI) indicate that As and Cd pose a high ecological risk, whereas Cu and Pb pose a low risk to biota. Statistical analyses (PCA/PMF) demonstrate that metal contaminants originated from three types of anthropogenic sources: the smelting of metal ores, the leakage of tailings effluent, and coal consumption.
有毒痕量元素是水生生态系统中持续存在的环境问题。然而，由于缺乏定量分析和准确评估，导致控制和水管理策略缺乏指导。阳宗湖是中国云南省西南部近百万人口的主要淡水资源。近年来，由于工业磷石膏泄漏、污水排放和化学修复等人为活动的影响，该湖受到了严重污染。在这里，我们结合生态环境指数和多种统计分析方法，确定了湖床上部沉积物中 11 种有毒痕量元素的生态风险和污染程度。利用从沉积核心数据中开发的稳健回归模型确定了当地地球化学背景浓度。污染指数（EF/PLI）表明，西南部分的 As 污染严重。其他有毒痕量元素（如 Cd、Cu、Pb）则轻度至中度富集，并从湖的西北向东南逐渐减少。本文提出了一个更准确和敏感的指数（PCR），表明在不同的湖段，污染主要由 As 和 Pb 主导。湖的北部和西南部海湾的污染物水平高于其他湖区。生物毒性指数（ERF/PERI）表明，As 和 Cd 对生物具有高生态风险，而 Cu 和 Pb 则风险较低。统计分析（PCA/PMF）表明，金属污染物源自三种人为来源：金属矿石的冶炼、尾矿废水的泄漏和煤炭的消耗。
