Department of Earth Sciences, Indian Institute of Technology, Roorkee, 247667, India.
Hydrological Investigations Division, National Institute of Hydrology, Roorkee, 247667, India.
Environ Sci Pollut Res Int. 2024 May;31(25):37196-37214. doi: 10.1007/s11356-024-33601-6. Epub 2024 May 20.
The transport and deposition of atmospheric pollutants in the Himalayas have a adverse impact on the climate, cryosphere, ecosystem, and monsoon patterns. Unfortunately, there is a insufficiency of data on trace element concentrations and behaviors in the high-altitude Himalayan region, leading to limited research in this area. This study presents a comprehensive and detailed comprehension of trace element deposition, its spatial distribution, seasonal variations, and anthropogenic signals in the high-altitude Kashmir region of the Western Himalayas. Our investigation involved the analysis of 10 trace elements (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) in glacier ice, snow pits, surface snow, and rainwater collected at various sites including Kolahoi, Thajwas, Pahalgam (Greater Himalayan ranges), and Kongdori and Shopian (Pir Panjal Ranges) during 2021. The study reveals distinct ranges of concentrations for the trace elements at different sampling sites. Our analysis of trace element concentration depth profiles in snow pits reveals seasonal fluctuations during the deposition year. The highest concentrations were found in the autumn (below 20 cm) and summer (top layer), compared to the winter concentration (10-20 cm). The high enrichment factors (EFs) suggest the severity of human-induced trace metal deposition in the western Himalayan region, relative to surrounding regions. Surprisingly, the concentrations and EFs of trace elements showed seasonal contradictions, with lower concentration values and higher EFs during the non-monsoon season and vice versa. A source apportionment analysis using the positive matrix factorization (PMF) technique identified five sources of trace element deposition in the region, including crustal sources (32.33%), coal combustion (15.62%), biomass burning (17.63%), traffic emission (18.8%), and industrial sources (15.6%). Additionally, the study incorporated backward trajectories coupled with δO using the NOAA HYSPLIT model to estimate moisture sources in the region, which suggests atmospheric pollutants predominately deposited from the large-scale atmospheric circulation from westerlies (75%) during non-monsoon season. These findings underscore the urgent need for enhanced monitoring and research efforts in the future.
大气污染物在喜马拉雅山脉的传输和沉积对气候、冰冻圈、生态系统和季风模式都有不利影响。不幸的是，关于高海拔喜马拉雅地区微量元素浓度和行为的数据不足，导致该领域的研究有限。本研究全面详细地了解了微量元素在喜马拉雅山西部高海拔克什米尔地区的沉积、空间分布、季节性变化和人为信号。我们的研究包括分析 2021 年在科拉霍伊、塔杰瓦斯、帕哈甘姆（大喜马拉雅山脉）以及孔多里和肖皮安（皮尔潘杰尔山脉）等不同地点采集的冰川冰、雪坑、表面雪和雨水样品中的 10 种微量元素（Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、Cd 和 Pb）。研究结果揭示了不同采样点的微量元素浓度范围不同。我们对雪坑中微量元素浓度深度剖面的分析表明，在沉积年中存在季节性波动。秋季（<20cm）和夏季（顶层）的浓度最高，而冬季（10-20cm）的浓度最低。高富集因子（EF）表明，与周边地区相比，人类活动导致西喜马拉雅地区痕量金属沉积的严重程度较高。令人惊讶的是，痕量元素的浓度和 EF 表现出季节性矛盾，即非季风季节的浓度值较低，EF 值较高，反之亦然。使用正定矩阵因子（PMF）技术进行的源分配分析确定了该地区痕量元素沉积的五个来源，包括地壳源（32.33%）、煤炭燃烧（15.62%）、生物质燃烧（17.63%）、交通排放（18.8%）和工业源（15.6%）。此外，该研究还结合了使用 NOAA HYSPLIT 模型的后向轨迹和 δO，以估计该地区的水汽来源，这表明非季风季节大气污染物主要是从西风（75%）的大规模大气环流中沉积下来的。这些发现强调了未来加强监测和研究工作的迫切需要。
