College Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission, College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China.
Bureau of Hydrology, Changjiang Water Resources Commission, Wuhan 430010, China.
Sci Total Environ. 2022 Oct 10;842:156683. doi: 10.1016/j.scitotenv.2022.156683. Epub 2022 Jun 11.
Heavy metal contamination of river water and sediments is a global issue affecting ecological health. To reveal heavy metals' ecological risks and biological toxicity in the middle and lower Han River (MLHR), sediment samples collected in this area were analyzed based on a modified ecological risk assessment method (NIRI) and a biological toxicity assessment method. Also, Spearman correlation analysis and Positive Matrix Factorization (PMF) methods were applied to identify the potential sources of heavy metals. The results indicated that the heavy metal content significantly exceeded the background concentrations in Hubei Province. The average potential risk of heavy metals at sampling sites was: Cd > Hg > As > Pb > Cu > Zn. Consequently, high biological toxicity occurred along the MLHR due to the heavy metal enrichment. River damming and water diversion significantly enhanced the hydrologic regime variations and ecological risk in the MLHR. Moreover, two possible pollution sources of the MLHR were identified: one is a combined source of traffic pollution, agricultural pollution, and partial industrial pollution consisting of five heavy metals, Pb, Hg, Zn, Cu, and As, the other is an industrial pollution source dominated by Cd and As. This study provides insights into sediment heavy metal pollution management and ecological risk control in the MLHR and similar rivers worldwide.
河流水中和沉积物中的重金属污染是一个全球性问题，影响着生态健康。为了揭示中下游汉江水（MLHR）中重金属的生态风险和生物毒性，本研究基于改进的生态风险评估方法（NIRI）和生物毒性评估方法，对该地区采集的沉积物样品进行了分析。此外，还应用 Spearman 相关分析和正矩阵因子分析（PMF）方法来识别重金属的潜在来源。结果表明，重金属含量明显超过湖北省的背景浓度。采样点重金属的平均潜在风险为：Cd > Hg > As > Pb > Cu > Zn。因此，由于重金属的富集，MLHR 沿线出现了高生物毒性。河坝和引水工程显著增强了 MLHR 的水文学变化和生态风险。此外，还确定了 MLHR 的两个可能污染源：一个是由交通污染、农业污染和部分工业污染组成的综合污染源，包含 5 种重金属，即 Pb、Hg、Zn、Cu 和 As，另一个是由 Cd 和 As 主导的工业污染源。本研究为 MLHR 和世界其他类似河流的沉积物重金属污染管理和生态风险控制提供了新的见解。
