Kaphle Binija, Wang Junbo, Ju Jianting, Lü Xinmiao, Kai Jinlei, Clarke Leon, Khanal Binish Raj, Humagain Sima, Srivastava Gaurav, Paudayal Khum Narayan
State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Nam Co Observation and Research Station (NAMORS), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Monit Assess. 2024 Dec 26;197(1):97. doi: 10.1007/s10661-024-13566-2.
Freshwater ecosystems, including high-altitude lakes, can be affected by trace metal pollution derived from a mix of natural sources and anthropogenic activities. These pollutants often collect in surface sediments, with notable concentrations in the deeper areas of lakes. To evaluate the environmental risk associated with metal contaminated sediment in Rara Lake, southern Himalaya, surface sediment samples were systematically collected in November 2018, with a subsequent specific emphasis on determinations of trace element concentrations. Subsequent analysis revealed nine elements exhibiting a descending mean concentrations order: iron (Fe) > manganese (Mn) > chromium (Cr) > rubidium (Rb) > nickel (Ni) > strontium (Sr) > cobalt (Co) > copper (Cu) > cadmium (Cd), of 7205.55 mg kg, 2290.34 mg kg, 176.29 mg kg, 153.78 mg kg, 51.86 mg kg, 44.61 mg kg, 38.89 mg kg, 29.11 mg kg, and 0.10 mg kg, respectively. Comparisons to sediment quality guidelines highlight that Mn, Cr, Cu, and Cd as significant threats to the aquatic ecosystem in Rara Lake. To assess the impact of metal pollution, enrichment factor (EF), geo-accumulation index (I), pollution load index (PLI), and contamination factor (CF) were computed. All metals (except Cd) had I value exceeding 5, displaying strong contamination. EF values for Mn, Cr, Co, and Ni metals were > 10, indicating severe effects of anthropogenic influences. CF and PLI values also indicated significant pollution for most of the investigated sites. Elevated trace element concentrations have the potential to adversely affect water, sediment, and aquatic life, also potentially impacting nutrient cycling and microbial activity. This study enhances our understanding of the metal compositions within Rara Lake sediments and provides a basis for more effective lake management and pollution control strategies. Urgent action by regional governing bodies is crucial to address the early stages of metals pollution, including identification and controlling of pollution sources, by appropriate regulations, optimizing industrial practices, and remediating existing pollution to prevent further contamination and protect the lake ecosystem.
包括高海拔湖泊在内的淡水生态系统，可能会受到源自自然源和人为活动混合的微量金属污染的影响。这些污染物通常会在表层沉积物中聚集，在湖泊较深区域有显著的浓度。为了评估喜马拉雅山脉南部拉腊湖金属污染沉积物相关的环境风险，于2018年11月系统地采集了表层沉积物样本，随后特别着重于微量元素浓度的测定。后续分析揭示了9种元素呈现出平均浓度递减顺序：铁（Fe）＞锰（Mn）＞铬（Cr）＞铷（Rb）＞镍（Ni）＞锶（Sr）＞钴（Co）＞铜（Cu）＞镉（Cd），其含量分别为7205.55毫克/千克、2290.34毫克/千克、176.29毫克/千克、153.78毫克/千克、51.86毫克/千克、44.61毫克/千克、38.89毫克/千克、29.11毫克/千克和0.10毫克/千克。与沉积物质量指南的比较表明，锰、铬、铜和镉对拉腊湖的水生生态系统构成重大威胁。为了评估金属污染的影响，计算了富集因子（EF）、地累积指数（I）、污染负荷指数（PLI）和污染因子（CF）。所有金属（镉除外）的I值均超过5，显示出强烈的污染。锰、铬、钴和镍金属的EF值＞10，表明人为影响的严重程度。CF和PLI值也表明大多数调查地点存在显著污染。微量元素浓度升高有可能对水、沉积物和水生生物产生不利影响，也可能影响养分循环和微生物活动。本研究增进了我们对拉腊湖沉积物中金属成分的了解，并为更有效的湖泊管理和污染控制策略提供了依据。区域管理机构采取紧急行动对于应对金属污染的早期阶段至关重要，包括通过适当法规识别和控制污染源、优化工业实践以及修复现有污染，以防止进一步污染并保护湖泊生态系统。
