Basin Water Environmental Research Department, Hubei Provincial Key Laboratory of River and Basin Water Researchources and Ecoenvironental Sciences, Changjiang River Scientific Research Institute, Wuhan, 430010, China.
Changjiang River Scientifific Research Institute, Wuhan, 430010, China.
Environ Geochem Health. 2024 Sep 4;46(10):414. doi: 10.1007/s10653-024-02188-9.
Angqu, positioned in the eastern expanse of the Tibet Plateau, claims the title of the largest tributary to the Lancang River. In October and December of 2018, in the sediment of Angqu, a comprehensive investigation was conducted on nine heavy metals-arsenic (As), manganese (Mn), chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu), zinc (Zn), and nickel (Ni). This investigation aimed to scrutinize the spatial and temporal distribution patterns of these metals, assess the pollution status and ecological risks associated with the sediments, and delve into the sources contributing to their presence. The research results indicate that the average concentrations of As, Hg, and Cd in Angqu sediments exceed the soil background values of Tibet, while the concentrations of other heavy metals are below the soil background values of Tibet. Notably, arsenic poses potential ecological risks. In Angqu sediments, the concentrations of Mn, Cu, Ni, and Pb are generally higher in the wet season, but the seasonal variations of heavy metals in Angqu sediments are not significant. The sediments in the Angqu Basin are predominantly affected by mercury Hg, Cd, and As, with varying degrees of pollution at different sampling points. In the main stream of Angqu (City section), Hg pollution has reached above a moderate level, whereas As pollution near the tributary is only slightly polluted. The analysis of heavy metal sources reveals that there are five primary contributors to heavy metals in surface sediments of Angqu: parent material, agricultural activities, groundwater, atmospheric deposition, and other unidentified sources. Mn, Cr, Pb, and Ni are mainly derived from soil parent material, accounting for more than 50%. About 60.82% of As comes primarily from groundwater. Zn and Cd are mainly sourced from agricultural activities, accounting for 41.25% and 34.33%, respectively. Additionally, 20.6% of Hg originates from atmospheric deposition.
昂曲，地处青藏高原东部，是澜沧江最大的支流。2018 年 10 月和 12 月，在昂曲沉积物中，对砷（As）、锰（Mn）、铬（Cr）、镉（Cd）、铅（Pb）、汞（Hg）、铜（Cu）、锌（Zn）和镍（Ni）这 9 种重金属进行了综合调查。本次调查旨在研究这些金属的时空分布规律，评估沉积物的污染状况和生态风险，并探讨其来源。研究结果表明，昂曲沉积物中 As、Hg 和 Cd 的平均浓度超过了西藏土壤背景值，而其他重金属的浓度低于西藏土壤背景值。砷具有潜在的生态风险。在昂曲沉积物中，Mn、Cu、Ni 和 Pb 在雨季的浓度普遍较高，但昂曲沉积物中重金属的季节性变化并不显著。昂曲流域沉积物主要受汞（Hg）、Cd 和 As 的影响，不同采样点的污染程度不同。在昂曲干流（城区段），Hg 污染已达到中度以上水平，而支流附近的 As 污染仅为轻度污染。重金属源分析表明，昂曲表层沉积物中重金属有 5 个主要来源：母质、农业活动、地下水、大气沉降和其他不明来源。Mn、Cr、Pb 和 Ni 主要来源于土壤母质，占比超过 50%。约 60.82%的 As 主要来源于地下水。Zn 和 Cd 主要来源于农业活动，分别占 41.25%和 34.33%。此外，20.6%的 Hg 来源于大气沉降。
