Dong Huike, Wang Lanxiang, Wang Xiaoping, Xu Li, Chen Mengke, Gong Ping, Wang Chuanfei
Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
School of Science, University of Chinese Academy of Sciences, Beijing, Beijing 100049, China.
Environ Sci Technol. 2021 Oct 5;55(19):12951-12960. doi: 10.1021/acs.est.1c03227. Epub 2021 Sep 15.
Plastic pollution is fast becoming one of the most pressing global issues that we currently face. Remote areas, such as the polar regions and the Tibetan Plateau, are now also exposed to microplastic contamination. However, with the impact of global warming, the transport of microplastics within the glacier-lake basins in such regions remains unclear. In this work, the Nam Co Basin in the Tibetan Plateau was selected to study the characteristics of microplastics in the rain fallout, lake water, glacial runoff, and non-glacial runoff. Fiber and films were the most common microplastic morphologies in all water samples; a higher proportion (37%) of light-weighing polypropylene and small-size (50-300 μm, ∼30%) microplastics were found in the glacial runoff. Air mass trajectory analysis showed that microplastics could be transported through the atmosphere over a distance of up to 800 km. For microplastic loading in lakes, the atmospheric fallout was estimated to be 3.3 tons during the monsoon season, whereas the contributions of glacial runoff (∼41 kg) and non-glacial runoff (∼522 kg) were relatively low. For the microplastic loading in glaciers, the atmospheric deposition was ∼500 kg/yr, and the output caused by glacial melting only accounted 8% of the total atmospheric input. All these results suggested that the dominant pathway through which microplastics enter remote mountainous lake basins is atmospheric deposition, and once deposited on glaciers, microplastics will be stored for a long time. This work provides quantitative evidence elucidating the fate of microplastics in alpine lake environments.
塑料污染正迅速成为我们当前面临的最紧迫的全球问题之一。偏远地区，如极地地区和青藏高原，现在也受到微塑料污染的影响。然而，受全球变暖的影响，这些地区冰川湖泊流域内微塑料的迁移情况仍不清楚。在这项研究中，选取了青藏高原的纳木错流域，以研究降雨、湖水、冰川径流和非冰川径流中微塑料的特征。纤维和薄膜是所有水样中最常见的微塑料形态；在冰川径流中发现较高比例（37%）的轻质聚丙烯和小尺寸（50 - 300μm，约30%）的微塑料。气团轨迹分析表明，微塑料可通过大气传输达800公里。对于湖泊中的微塑料负荷，季风季节大气沉降估计为3.3吨，而冰川径流（约41公斤）和非冰川径流（约522公斤）的贡献相对较低。对于冰川中的微塑料负荷，大气沉降约为500公斤/年，冰川融化造成的输出仅占大气总输入的8%。所有这些结果表明，微塑料进入偏远山区湖泊流域的主要途径是大气沉降，一旦沉积在冰川上，微塑料将长期储存。这项工作提供了定量证据，阐明了微塑料在高山湖泊环境中的归宿。
