LANZHOU, April 2 (Xinhua) -- A new study by Chinese researchers has helped people better understand how microplastics "move" on the Qinghai-Tibet Plateau and has sustained plastic pollution prevention and control efforts, according to the Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences.
Through in situ sampling and quantitative analysis, the study explored the dynamics of suspended atmospheric microplastics and their wet deposition in the Qilian Mountains in the northeastern part of the Qinghai-Tibet Plateau, said the institute.
Also known as the "Water Tower of Asia," the Qinghai-Tibet Plateau has been considered a remote area with little direct impact from anthropogenic pollutants due to its high altitude, cold climate, and sparse human activities. However, recent studies show that new pollutants, such as microplastics, can reach this plateau region via long-distance atmospheric transport.
Compared with understanding the dynamics of microplastics in densely populated areas, it is more significant to better understand the distribution patterns, deposition processes, and driving mechanisms of atmospheric microplastics in plateau regions, according to Zhang Yulan, a researcher at the NIEER.
The NIEER study team conducted systematic atmospheric sampling in the Qilian Mountains.
Researchers analyzed atmospheric suspended microplastics and their wet deposition dynamics, accurately measuring the size, polymer type, and various morphological parameters of individual microplastic particles.
In general, microplastic abundance in the study areas was lower than in high-density population areas. Suspended atmospheric microplastics and wet deposition microplastics were dominated by fragments, with the percentage over 70 percent, according to the study results.
This study indicates that suspended microplastics in these regions have a wider size range and a higher degree of fragmentation, suggesting they underwent longer atmospheric transport and aging processes.
The research team introduced "sphericity" as a continuous variable to quantify the atmospheric transport potential of microplastics of different shapes. Analysis showed that low-sphericity microplastics are more likely to achieve long-distance transport, while high-sphericity particles tend to undergo local deposition.
"Our new study provides key scientific evidence for unveiling the transport and deposition of atmospheric microplastics in high-altitude regions," Zhang said.
These new findings offer important scientific support for improving global atmospheric microplastic cycle models, more rigorously assessing ecological risks in remote cryospheric regions, and supporting the formulation of plastic pollution prevention policies, according to Zhang.
The study results have been published in the Journal of Environmental Sciences. ■
