New insights into the long-term dynamics and deposition-suspension distribution of atmospheric microplastics in an urban area

Atmospheric microplastics (AMPs) transmitted through the atmosphere are critical to global microplastic pollution. However, little is known about the long-term dynamics and distribution patterns of deposited (DAMPs) and suspended (SAMPs) AMPs. In this study, simultaneous sampling was conducted over one year to examine the deposition-suspension distribution of AMPs. Monthly and seasonal variations in abundance were evident, with an annual average of 302.31 ± 107.40 items/m2/day for DAMPs and 1.31 ± 0.62 items/m3 for SAMPs. The dynamics of DAMP and SAMP abundance demonstrated the dynamic distribution of AMPs between deposition and suspension. Both meteorological factors and particle features were found to influence the AMP distribution, manifesting as morphological differences and abundance variations. AMPs were most likely derived from traffic, industry, construction, and synthetic textiles, with diverse source areas up to 1750 km away. The estimated deposition flux of 7.28 × 1014 items per year and inhalation exposure of up to 12,777 items per year highlight the potential ecological and health risks of AMPs.