School of Geographical Sciences, Southwest University, Chongqing 400045, China; State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
School of Geographical Sciences, Southwest University, Chongqing 400045, China.
Sci Total Environ. 2022 Nov 1;845:157308. doi: 10.1016/j.scitotenv.2022.157308. Epub 2022 Jul 15.
Knowledge of the elemental composition of aerosols at remote sites is important for evaluating the influence of anthropogenic activities. In this study, the elemental composition and sources of total suspended particles (TSP) at Yaze, a remote site in the southeastern Tibetan Plateau (TP), were investigated. The results showed that the mean elemental concentrations at Yaze were relatively low compared with those in other areas of the TP. Seasonal variations in the studied elements was characterized by low and high concentrations during the monsoon and non-monsoon periods, respectively. The enrichment factors (EFs) for some heavy metals at Yaze were slightly higher than those at Nam Co station (inland TP) but much lower than those at Mt. Yulong (southeastern TP) and in the Indian megacity of Delhi, indicating fewer anthropogenic influences at the study site relative to sites close to severely polluted regions. For the studied elements, three major sources were identified: crustal origins (e.g., Al and Fe), anthropogenic origins (e.g., Zn and Cd) and mixed origins (e.g., As and Bi). Further analysis by potential source contribution functions showed that the local TP was the primary source for elements of crustal origins. Correspondingly, the typical heavy metals were mainly attributed to pollution emitted from anthropogenic activities and transported over long-range from both South and Southeast Asia. This work demonstrates the transport of heavy metals from external sources to remote sites in the southeastern TP. These results are also useful for interpreting the historical profiles of heavy metals in the ice cores of the TP.
在偏远地区了解气溶胶的元素组成对于评估人为活动的影响非常重要。本研究调查了青藏高原东南部雅则偏远地区总悬浮颗粒物（TSP）的元素组成和来源。结果表明，与青藏高原其他地区相比，雅则的平均元素浓度相对较低。研究元素的季节性变化特征是季风期和非季风期分别为低浓度和高浓度。雅则的一些重金属的富集因子（EF）略高于那木错站（内陆青藏高原），但远低于玉龙雪山（青藏高原东南部）和印度大都市德里，表明与靠近污染严重地区的站点相比，研究点的人为影响较少。对于研究的元素，确定了三个主要来源：地壳来源（如 Al 和 Fe）、人为来源（如 Zn 和 Cd）和混合来源（如 As 和 Bi）。潜在源贡献函数的进一步分析表明，当地的青藏高原是地壳起源元素的主要来源。相应地，典型的重金属主要归因于来自南亚和东南亚的人为活动排放并长距离传输的污染。这项工作表明，重金属从外部源向青藏高原东南部的偏远地区传输。这些结果对于解释青藏高原冰芯中重金属的历史分布也很有用。
