National Centre of Excellence in Geology, University of Peshawar, Peshawar, 25130, Pakistan.
Department of River Ecology, Helmholtz Centre for Environmental Research-UFZ, Brückstra, 3a, 39114, Magdeburg, Germany.
Environ Monit Assess. 2024 Nov 12;196(12):1188. doi: 10.1007/s10661-024-13361-z.
Lake ecosystems in northern Pakistan are the most critical resources that maintain and regulate water flow for downstream agricultural, domestic, industrial, and ecological processes. One consequence of these processes is that ecosystems deposit heavy metals (HMs), where lake stagnant conditions result in high vulnerability of water resources. For this purpose, the present study examined HMs such as cadmium (Cd), chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) concentrations in high-altitude lakes (HAL) sediments of Mansehra district, northern Pakistan. Sediment samples were collected from the five HAL. This study used HM concentrations in lake sediments for the pollution factors such as contamination factor (C), pollution load index (PLI), sediment pollution index (SPI), ecological risk assessment (ERA), and risk index (RI). Among HMs, Fe showed the uppermost levels of 1410 mg/kg in lake sediment, while Cd with lowermost levels of 1.05 mg/kg. Results revealed that most HM concentrations in HAL sediments were within the threshold of sediments quality guidelines (SQGs), except for Cd. Among lakes, the sediments of Siri Lake showed higher contamination of HMs than others. Siri Lake sediments also showed higher C, PLI, ERA, and RI values than others. The majority of HMs in HAL sediments showed no contamination, except for Cd (considerable) and Pb (moderate) levels to the exposed aquatic ecosystem. This study revealed that 95% of sediment samples in HAL were noted low to medium-level risks to the exposed aquatic communities. Statistical and geospatial analyses revealed that geogenic sources of contamination are a significant contributor to HM contamination of HAL sediments compared to others.
巴基斯坦北部的湖泊生态系统是维持和调节下游农业、国内、工业和生态过程用水的最关键资源。这些过程的一个后果是，生态系统会沉积重金属（HM），而湖泊停滞的条件会导致水资源高度脆弱。为此，本研究检测了巴基斯坦曼塞赫拉地区高海拔湖泊（HAL）沉积物中的重金属（如镉（Cd）、铬（Cr）、钴（Co）、铁（Fe）、锰（Mn）、镍（Ni）、铅（Pb）和锌（Zn））浓度。本研究从五个 HAL 采集了沉积物样本。本研究使用湖泊沉积物中的重金属浓度来评估污染因子，如污染因子（C）、污染负荷指数（PLI）、沉积物污染指数（SPI）、生态风险评估（ERA）和风险指数（RI）。在重金属中，Fe 在湖泊沉积物中的含量最高，为 1410 mg/kg，而 Cd 的含量最低，为 1.05 mg/kg。结果表明，除 Cd 外，大多数 HAL 沉积物中的重金属浓度均在沉积物质量指南（SQGs）的阈值范围内。在湖泊中，Siri 湖的沉积物中重金属污染程度高于其他湖泊。Siri 湖沉积物的 C、PLI、ERA 和 RI 值也高于其他湖泊。除 Cd（大量）和 Pb（中度）对暴露水生态系统外，大多数 HAL 沉积物中的重金属没有污染。本研究表明，95%的 HAL 沉积物样本对暴露水生物群落的风险处于低至中度水平。统计和地理空间分析表明，与其他来源相比，地质来源的污染是 HAL 沉积物重金属污染的一个重要因素。
