Characteristics and potential ecological risk assessment of atmospheric microplastics in Lhasa city

Abstract Atmospheric microplastics is a key contributor to environmental contamination in aquatic and terrestrial systems, posing potential ecological risks. However, studies on atmospheric microplastics are still limited in urban regions of the Tibetan Plateau, a sentinel region to climate and environmental change under the warming climate. Based on samples of suspended atmospheric microplastics (SAMPs) in Lhasa City collected during the Tibetan New Year in February 2023, the occurrence, potential ecological risk of atmospheric microplastics were investigated. The results showed that the average abundance of microplastics in the atmospheric environment of Lhasa was 7.15 ± 2.46 ietms·m− 3.The sizes of detected microplastic ranged from 20.34 µm to 297.18 µm, with approximately 87% smaller than 100 µm. Fragmented microplastics (95.76%) were the dominant format, followed by fibers (3.75%), and pellets (0.49%), respectively. The primary polymer chemical components identified were polyamide (PA,68.73%) and polystyrene (PS,16.61%), respectively. According to the analysis of meteorological data and backward trajectory model, the trajectory of the air mass in Lhasa is obviously westward, and the atmospheric microplastics mainly come from the long-distance transmission of the atmosphere. The results of potential ecological risk index (PERI) assessment indicated that the atmospheric microplastic pollution in Lhasa was at a low level. This study provides valuable insights and a scientific foundation for future research on the prevention and control of atmospheric microplastic pollution in Lhasa and other ecologically sensitive cities.