Assessment of suspended atmospheric microplastics in Tianjin Binhai New Area: characterization, human health risks, and correlation with weather conditions and Air Quality Index.

Suspended atmospheric microplastics (SAMPs), as a critical component of environmental microplastic pollution, have garnered substantial scientific interest. The characterization of SAMPs in urban environments, as well as the potential risks on health, continues to be a topic of significant research interest. This study provides a comprehensive report on the presence of SAMPs in the Binhai New Area of Tianjin, China, based on samples collected during the autumn and winter of 2023-2024 using a medium-flow total suspended particulate (TSP) sampler at a monitoring station. Microplastics were detected in all samples, with concentrations ranging from 0.2 to 1.8 items/m in autumn and from 0.1 to 1.1 items/m in winter, and a total mean of 0.6 ± 0.4 items/m. Particle sizes spanned 12.28-3248.58 µm, with fibrous shapes dominating the morphological composition. Observed colors included black, blue, yellow, transparent, red, and green, with black microplastics being the most prevalent. These SAMPs were composed of polyethylene terephthalate, polyethylene, rayon, polypropylene, and ethylene-ethyl acrylate copolymer. A risk assessment indicated that residents of Binhai New Area, Tianjin City, face a measurable health risk from microplastic exposure. Significant correlations were identified between SAMPs and dew point temperature as well as relative humidity in the autumn. In the winter, significant correlations were observed between the abundance of SAMPs and ground barometric pressure and wind velocity. Weak negative correlations were observed between SAMP abundances and the Air Quality Index (AQI) in both seasons Future research will utilize more advanced technologies and establish a global monitoring network to further explore the sources, distribution, and impacts of atmospheric microplastics.