Ecological and human health risks of atmospheric microplastics (MPs): a review

Microplastics (MPs) in the atmosphere are ubiquitous and persistent emerging pollutants which have been an environmental issue of global concern. This overview summarizes the sources, morphological size and compositional characteristics, spatial-temporal distributions, transport and fates, and both ecological and human health risks of MPs in the atmospheric environment. The results suggest that atmospheric MPs could be long-range transported and deposited into aquatic and terrestrial habitats, which pose ecological risks through bio-absorption, bio-concentration, bio-accumulation, ecotoxicity and associated chemical pollution. Since a large number of small-sized MPs are present in the atmosphere, exposure to them affects ingestion, metabolism and reproduction. Human exposure to atmospheric MPs by inhalation may induce health risks, including oxidative stress and inflammatory damage. Moreover, atmospheric MPs may also serve as carriers for other harmful chemical pollutants like heavy metals. Finally, further research studies on atmospheric MPs are recommended for future work.