重金属对环境和人类健康都构成重大威胁。考虑到青藏高原(TP)的微妙生态平衡及其对人为影响的高度敏感性,学术界的注意力逐渐转向对高原环境中重金属污染的研究。在这项研究中,我们对各种重金属(As,Cr,Co,Ni,Cu,Mo,Cd,Pb,和Sb),利用2018-2021年期间从TP收集的表土样品。此外,在同一时间段内从TP冰川获得的雪和冰冻岩样品也进行了分析。结果表明,东部和西部TP的总重金属浓度升高(328.7μg/g),与中部和南部TP(145.7μg/g)相反。大多数重金属表现出一致的空间分布模式。As和Cd的高富集因子(EF)和地积累指数(Igeo)值表明它们在TP表层土壤中的富集。受体模型确定了表层土壤中重金属的三种主要来源:工业来源(42.3%),表层土壤中固有的天然来源(20.6%),和车辆排放(14.2%)。在表层土壤和冰川雪-冰冻岩基质之间观察到重金属浓度和空间分布的显着差异。雪-冰冻岩基质中Sb的突出存在,与其在表土中的低丰度相比,表明两种环境之间远程运输材料的不同来源影响。我们的推断表明,由于当地本地重金属的存在,来自远处污染物的重金属的影响在表层土壤中发生混合和稀释,尽管在TP的冰川表面上明显观察到了这种影响。因此,这突显了远距离运输来源对重金属的重大影响,超越当地TP土壤的影响,到青藏高原的高山冰川甚至其他大气沉积物。
Heavy metals present a substantial threat to both the environment and human health. Considering the delicate ecological equilibrium of the Tibetan Plateau (TP) and its heightened susceptibility to anthropogenic impacts, scholarly attention has progressively turned toward the examination of heavy metal pollution within the plateau\'s environment. In this study, we conducted a comprehensive analysis of various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb, and Sb), utilizing
topsoil samples collected from the TP during the period of 2018-2021. Additionally, snow and cryoconite samples obtained from TP glaciers during the same timeframe were also subjected to analysis. The results indicate elevated concentrations of total heavy metals in the eastern and western TP (328.7 μg/g), as opposed to the central and southern TP (145.7 μg/g). Most heavy metals exhibit a consistent spatial distribution pattern. High Enrichment Factors (EFs) and Geoaccumulation Index (Igeo) values for As and Cd suggest their enrichment in TP
topsoil. Receptor modeling identified three primary sources of heavy metals within the
topsoil: industrial sources (42.3%), inherent natural sources within the surface soil (20.6%), and vehicular emissions (14.2%). Substantial differences in heavy metal concentrations and spatial distribution were observed between the topsoil and the glacial snow-cryoconite matrix. The prominent presence of Sb in the snow-cryoconite matrix, in contrast to its low abundance in the
topsoil, indicates distinct source influences of long-range transported materials between the two environments. Our inference suggests that the influence of heavy metals from distant pollutants undergo mixing and dilution in the
topsoil due to the presence of local indigenous heavy metals, although such influence is notably observed on the glacier surface of the TP. Consequently, this underscores the significant impact of long-range transported sources on heavy metals, surpassing the influence of local TP soils, to the alpine glaciers and even other atmospheric sediments in Tibetan Plateau.