Microplastics in ambient air: a review of atmospheric abundance, human exposure and urgent research needs

Microplastics are plastic particles less than 5 mm in size that have been identified as important pollutants in the environment today. In this study, the results from 84 studies published between 2019 and 2025 were reviewed and important findings regarding microplastics, which include abundance, composition, routes of human exposure and health hazards were addressed. Microplastics have been identified in all environments, including indoor, outdoor, urban and even the natural environment in remote areas such as Antarctica, demonstrating the importance of the atmospheric transport of microplastics and their subsequent movement in the air over long distances. The results of these studies show that fibers, among the microplastic forms identified, were the most predominant type, particularly particulates less than 100 µm in size. Additionally, regarding polymer compositions, PET, PE, PP and PS were reported at higher abundances in the results. Various analytical assays have been performed to identify and analyze microplastics, including Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, which have been used throughout the studies. Health studies provide evidence that these particles are associated with respiratory inflammation, oxidative stress and metabolic conditions, necessitating further epidemiological studies to assess both short- and long-term exposures. Furthermore, microplastics pose significant environmental concerns.