Microplastics in Aquatic Ecosystems: Pathways, Impacts and Integrated Solutions for Environment and Human Health

Plastic pollution has rapidly evolved into a global environmental crisis, with microplastics emerging as ubiquitous and persistent contaminants across freshwater and marine ecosystems. This review synthesizes current knowledge on the origin, distribution, and ecological consequences of microplastics, emphasizing their complex environmental behavior and widespread biological uptake. Microplastics are introduced through diverse pathways, including wastewater effluents, urban and agricultural runoff, atmospheric deposition, and the degradation of larger plastic debris. Once in the aquatic environment, they undergo transformation via photochemical, mechanical, and biological processes, facilitating their dispersal and interaction with biota and co-pollutants. Ingestion of microplastics by a broad range of organisms has been documented, with evidence of bioaccumulation, trophic transfer, and physiological harm. Moreover, microplastics act as vectors for hazardous chemicals and pathogens, raising critical concerns for food safety and human health. Current removal technologies are limited in scope and efficiency, particularly in natural settings. We highlight an urgent need for integrated solutions that combine upstream interventions (e.g., reduced plastic use and improved product design) with downstream innovations (e.g., advanced filtration, bioremediation, and policy enforcement). A global, interdisciplinary response is essential to mitigate the long-term impacts of microplastic pollution and safeguard aquatic ecosystems and public health.