Composition, interactions and resulting inhalation risk of micro- and nano-plastics in urban air

Abstract Airborne micro- and nano-plastics represent an underestimated threat to urban environments and human health. We characterized their concentrations and polymer composition in size-fractionated particulate matter collected in Leipzig, Germany, using pyrolysis gas chromatography mass spectrometry. Total concentrations of plastic particles <10 µm averaged 0.6 ± 0.2 µg/m 3 , with fine and coarse fractions contributing equally. Tire wear particles dominated, accounting for about 65% total plastics, followed by polyvinyl chloride, polyethylene, and polyethylene terephthalate. These polymers correlated strongly with carbonaceous aerosol markers, indicating co-emission and atmospheric mixing. Exposure and risk assessment suggest that inhalation of approximately 2.1 µg of these airborne plastic particles per day may increase cardiopulmonary mortality by 9% and lung cancer mortality by 13% in humans. By integrating exposure, risk assessment, and analytical data, these findings highlight the need for global policy action, emphasizing the value of region-specific research for air quality and public health initiatives.