Abstract：
Heavy metals present in aquatic ecosystems constitute a significant threat to both the environment and human health. In this study, we analyzed various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb and Sb) using extensive surface water samples collected from the Tibetan Plateau in 2021 and 2023. Results showed that downstream water samples exhibited higher content (mean 12.6 μg/L) of heavy metals compared to those from the glacier basins. It is noteworthy that heavy metal content varied significantly both in the glacier basin and downstream (4.6-29.1 μg/L and 7.8-55.2 μg/L, respectively). However, elevated concentrations at certain sites (e.g., Saga County and Dangque Zangbu River) were primarily attributed to the disproportionate contribution of individual heavy metals, possibly stemming from specific human activities or natural conditions. In the glacier basin, only Cr exhibited a decreasing trend in enrich factors (EF) with increasing Sc concentration, whereas, in the downstream areas, most elements displayed a declining trend. Furthermore, apart from a few sampling sites, heavy metal concentrations in the glacier basin remained relatively balanced, suggesting that these metals predominantly originate from natural sources. The values of potential ecological risk for an individual element (Eri) and potential ecological risk index (PER) indicate that the ecological and human risks associated with almost heavy metals (except As) in the aquatic ecosystem are minimal. ENVIRONMENTAL IMPLICATION: Heavy metals in aquatic ecosystems pose a significant threat to ecological and human health. Due to delicate ecological balance of the Tibetan Plateau and its critical role as a water resource, we analyzed various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb and Sb) concentrations and EF in land surface river water, to find out the pollution levels and possible sources of heavy metals in the aquatic ecosystems. The results of risk assessment showed that the prevention and management of arsenic in Tibetan Plateau needs attention, but most heavy metals pose no threaten to ecological and human health.
摘要：
水生生态系统中存在的重金属对环境和人类健康构成重大威胁。在这项研究中,我们分析了各种重金属(As，Cr,Co,Ni,Cu,Mo,Cd,Pb和Sb）使用2021年和2023年从青藏高原收集的大量地表水样品。结果表明，与冰川盆地相比，下游水样的重金属含量更高（平均12.6μg/L）。值得注意的是，冰川盆地和下游的重金属含量差异显着（4.6-29.1μg/L和7.8-55.2μg/L，分别)。然而,某些地点的浓度升高(例如，佐贺县和当克藏布河）主要归因于单个重金属的不成比例的贡献，可能源于特定的人类活动或自然条件。在冰川盆地，随着Sc浓度的增加，只有Cr的富集因子（EF）呈下降趋势，然而,在下游地区，大多数元素呈现下降趋势。此外，除了几个采样点，冰川盆地的重金属浓度保持相对平衡，这表明这些金属主要来自天然来源。单个元素（Eri）和潜在生态风险指数（PER）的潜在生态风险值表明，与水生生态系统中几乎重金属（As除外）相关的生态和人类风险最小。环境意义：水生生态系统中的重金属对生态和人类健康构成重大威胁。由于青藏高原微妙的生态平衡及其作为水资源的关键作用，我们分析了各种重金属(As，Cr,Co,Ni,Cu,Mo,Cd,陆地地表水中的Pb和Sb）浓度和EF，了解水生生态系统中重金属的污染水平和可能来源。风险评估结果表明,青藏高原地区砷的防治工作需要重视,但是大多数重金属对生态和人类健康没有威胁。
