Understanding the atmospheric cycle of microplastics: from emission to deposition

Abstract

Atmospheric microplastic (AMP) has recently emerged as a potential vector in the global carbon cycle, and a novel factor influencing the climate system. Previous studies on microplastics primarily focused on terrestrial and aquatic ecosystems, while research on AMP remains insufficient. Given the unique mobility of AMP and its function as a vector linking land, ocean, and atmosphere, this review provides a comprehensive synthesis of current knowledge on AMPs, with a focus on their sources, spatiotemporal distribution, transport and deposition processes, and detection and quantification techniques. Previous literature indicates that AMP originates from diverse sources, and its atmospheric distribution exhibits pronounced spatial heterogeneity, with transmission and deposition processes driven by meteorological conditions, particle properties, and surface–atmosphere interactions. However, substantial knowledge gaps remain regarding standardized monitoring methods, long-range transport mechanisms, and the implications of AMPs for atmospheric processes and climate forcing. In particular, limitations in detection and quantification techniques hinder accurate assessment of AMP in the atmosphere. Here, this review provides theoretical support for a comprehensive understanding of the global cycle of AMP, which offers a scientific basis for relevant environmental risk assessment and climate management decisions.