Unveiling the suspended atmospheric microplastic pollution in a coastal urban landscape

This study investigated the presence and insights of suspended atmospheric microplastics (SAMPs) in a coastal urban setting of Xiamen, China, focusing on the downtown tourist and urban-rural fringe areas. The abundance of SAMPs in Xiamen ranged from 0 to 0.062 items m−3, with an average of 0.011 ± 0.012 items m−3. Notably, the urban-rural fringe area exhibited a higher abundance of SAMPs compared to the tourist area, attributing to surrounding pollution sources and the effectiveness of environmental policies. Fibers emerged as the dominant form of SAMPs, with microbeads and films also observed. Polyethylene terephthalate emerged as the dominant type, and transparent and blue SAMPs constituted the largest proportion. Over 50% of the SAMPs were smaller than 1 mm, with the smallest particle measuring 29 μm. Correlation and principal component analyses revealed that atmospheric pressure, relative humidity, wind speed, and wind direction significantly influenced the distribution of SAMPs. Backward trajectory modeling indicated that marine air masses diluted the SAMP pollution, whereas continental air masses exacerbated it. This study represents the first assessment of SAMP pollution in Xiamen, shedding light on the interplay between local pollution sources, environmental factors, air masses, industrial layout, and environmental policies. It emphasizes the need for increased attention to atmospheric microplastic pollution in coastal urban landscapes and underscores the importance of effective mitigation strategies.