Microplastics in freshwater and marine ecosystems: Occurrence, characterization, sources, distribution dynamics, fate, transport processes, potential mitigation strategies, and policy interventions

Most of the literature on microplastics (MPs) focuses on freshwater or terrestrial ecosystems, frequently overlooking their interconnections with the marine environments. This oversight is worrying given that both ecosystems serve as primary pathways for the introduction of MPs into marine environments. This review synthesizes existing literature on MPs in both freshwater and marine ecosystems across all six continents. The most commonly produced plastic polymers in industry are polyethylene (36 %) and polypropylene (21 %), and studies revealed that these two materials are the most abundant in aquatic ecosystems. Primary and secondary MPs originate from a range of sources including land-based disposal, the…