Microplastics in a remote lake basin of the Tibetan Plateau: Impacts of atmospheric transport and glacial melting

Plastic is fast becoming one of the most pressing global that we currently face. Remote areas, such as the polar regions the Tibetan Plateau, are now also exposed to microplastic contamination. , with the impact of global warming, the transport of microplastics the glacier-lake basins in such regions remains unclear. In work, the Nam Co Basin in the Tibetan Plateau was selected to the characteristics of microplastics in the rain fallout, lake, glacial runoff, and non-glacial runoff. Fiber and films were most common microplastic morphologies in all water samples; a proportion (37%) of light-weighing polypropylene and small-size (50–300 μm, ∼30%) microplastics were found in glacial runoff. Air mass trajectory analysis showed that microplastics be transported through the atmosphere over a distance of up 800 km. For microplastic loading in lakes, the atmospheric fallout estimated to be 3. 3 tons during the monsoon season, whereas the of glacial runoff (∼41 kg) and non-glacial runoff (∼522 kg) were relatively low. For the microplastic loading glaciers, the atmospheric deposition was ∼500 kg/yr, and output caused by glacial melting only accounted 8% of the total input. All these results suggested that the dominant pathway which microplastics enter remote mountainous lake basins is deposition, and once deposited on glaciers, microplastics be stored for a long time. This work provides quantitative evidence the fate of microplastics in alpine lake environments.