Microplastics Found from Glaciers of the Tibetan Plateau
Microplastics are globally prevalent on a large scale in various marine and terrestrial environments, including Arctic snow and precipitation in protected areas of the United Sates. However, reports of microplastics from glaciers are rare, especially for the Tibetan Plateau (TP), which is widely known as the world's Third Pole and Asian Water Tower. Adjacent to human settlements in South Asia, East China, and Central Asia, the TP features regular cross-border air pollution (e.g., black carbon and mercury), which can affect its vulnerable and pristine environments. In previous studies, abundant microplastics have been reported from Tibetan rivers/lakes water and sediments, and surface soils.
Recently, Prof. KANG Shichang’s group from the Northwest Institute of Eco-Environment and Resources (NIEER), Chinese Academy of Sciences (CAS), reported that microplastics were found from glacier surface snow on the TP. The results of indicated that three shapes of MPs were detected (fiber, fragment, and film) (Fig. 1a). For the measured MPs in snow, most fibers were black, similar to those detected from urban atmospheric deposition (Fig. 2a).
Tentative atmospheric particle modeling for 100 μm MP particles suggested local input of MPs in the studied areas (Fig. 1b). However, particle dispersion modeling, undertaken to consider 10 and 1 μm MP particles, suggested that the atmospheric transportation of MPs deposited on the studied glaciers mainly originated from Central Asia and South Asia (Fig. 1b). The population density and gross domestic product were intensively distributed around the TP (Fig. 2a and b). Simulations of annual ERA-Interim mean wind indicated that one branch of the westerly was forced from a high terrain into a northwesterly path (along the Himalayas) (Fig. 2c). Particularly in the spring season, when atmospheric brown clouds occur over South Asia, the polluted airmasses could reach the southern Himalayas and are further carried by the mountain-valley breeze circulation into the TP (Fig. 2d).
This work has been published on “Science of the Total Environment” recently entitle with “Microplastics in glaciers of the Tibetan Plateau: Evidence for the long-range transport of microplastics”. Dr. ZHANG Yulan is the first and co-corresponding authors.
Fig. 1 Microplastics measured from glacier snow in the Tibetan Plateau (a), and (b) atmospheric particle dispersion modeling of 100, 10, and 1 μmMP particles arriving at the Laohugou Glacier and Qiangyong Glacier. (Image by Dr. ZHANG)
Fig. 2 Distributions of (a) population and (b) gross domestic product around the Tibetan Plateau, and simulated ERA-Interimannual wind (c) and spring wind (d) in the Tibetan Plateau and its surroundings. (Image by Dr. ZHANG)
State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.