Microplastics in Aquatic Ecosystems: Sources, Impacts, and Challenges for Biodiversity, Food Security, and Human Health - A Meta Analysis

Background: Microplastics (MPs), plastic fragments under 5 mm in size, have become a pervasive global environmental concern due to their durability, prevalence in aquatic ecosystems, and adverse effects on biodiversity and human health. Originating as primary MPs from industrial applications or secondary MPs from the degradation of larger plastics, they infiltrate aquatic environments through various pathways. Their ability to bioaccumulate in food webs and release harmful chemicals poses significant ecological and health risks, particularly in regions with inadequate waste management. Methods: This study employed a comprehensive literature review, analyzing research on MP pollution in freshwater and marine ecosystems from November 2022 to June 2023. Keywords included “plastic pollution,” “microplastic contamination,” and “plastic waste management.” Sources encompassed peer-reviewed journals, grey literature, and unpublished reports from platforms like Google Scholar, ResearchGate, and local periodicals. Data were synthesized to assess MPs' ecological impacts, bioaccumulation, and interaction with pollutants. Results: Findings reveal the ubiquitous presence of MPs across aquatic habitats, with polyethylene (23%) and polystyrene (22%) being the most prevalent types. MPs were detected in various aquatic species, including fish (44%), crustaceans (21%), and mollusks (14%), often through ingestion or bioaccumulation. Evidence shows MPs induce oxidative stress, reproductive issues, and neurotoxicity in organisms. Their interaction with persistent organic pollutants (POPs) exacerbates toxicity, facilitating pollutant transfer across trophic levels. Regions with high plastic usage and poor waste management, particularly in Asia, contribute significantly to MP pollution. Conclusion: MP pollution represents a critical threat to aquatic ecosystems and human health, necessitating urgent global action. Sustainable practices, enhanced waste management, and public awareness are pivotal in mitigating MP contamination. Further research is required to address knowledge gaps, particularly concerning terrestrial impacts and the long-term effects of MP exposure on human health.