Microplastics in marine ecosystems: regional patterns, organism-level impacts and human exposure pathways
Description
Microplastics contaminate coastal and oceanic environments and create ecological risk through ingestion, tissue retention and trophic transfer. This review synthesised evidence from Scopus-indexed open-access research articles published from 2020 to 2024 and complemented it with National Centers for Environmental Information records on oceanic microplastic pollution from 2017 to 2022. The search retrieved 241 records and 42 studies met the eligibility criteria after title, abstract and full-text screening. The results show a regionally uneven evidence base, with stronger research concentration in the Atlantic and Pacific oceans and weaker coverage in the Indian, Arctic and Antarctic basins. Fibres were the dominant particle form, while polyethylene, polyester and polyethylene terephthalate were the most frequent polymers. The gastrointestinal tract and gills were the principal accumulation sites, with reported effects including digestive obstruction, respiratory impairment, oxidative stress, histopathological damage and reduced nutrient absorption. The evidence indicates plausible exposure pathways for humans through seafood, although methodological heterogeneity limits comparability among regions and taxa. Standardised sampling, polymer identification and reporting protocols, together with expanded monitoring in data-poor marine regions, are required to support risk assessment, pollution control and management of food species.