Dynamics of microplastic transport: A comprehensive review of atmospheric, terrestrial, and aquatic environments

Microplastics (MPs) are globally distributed contaminants that move across atmospheric, terrestrial, freshwater, and marine environments, transforming local pollution into a planetary-scale challenge. This review provides an integrated synthesis of the physical, chemical, and biological processes governing MP transport and fate across environmental compartments. In the atmosphere, wind-driven resuspension, waste incineration, and marine spray facilitate long-range dispersal through atmospheric circulation and deposition processes. In terrestrial systems, runoff, erosion, infiltration, and bioturbation drive both horizontal and vertical migration, intensified by agricultural practices. Rivers act as major transport pathways linking land-based sources to coastal and marine ecosystems. In aquatic environments, hydrodynamic forces, biofouling, aggregation, and biological interactions regulate particle transport, redistribution, and retention, ultimately promoting accumulation in sediments and other long-term environmental sinks. Attention is given to the influence of particle properties, environmental variables, and anthropogenic activities on transport dynamics. The review further examines the role of extreme weather events and climate change in modifying transport pathways and enhancing MP redistribution across environmental boundaries. Contrasting evidence regarding the effects of natural organic matter and biofilms is discussed, together with emerging challenges associated with MPs. Finally, key knowledge gaps related to methodological standardization, remote observations, and integrated multi-compartment modeling are identified. A mechanistic understanding of MP transport is essential for improving environmental risk assessment and supporting effective mitigation strategies.