Microplastics as Emerging Contaminants: Challenges in Inland Aquatic Food Web

Microplastic (MP) pollution in inland water bodies, such as rivers, lakes, and reservoirs, is a growing environmental concern, yet research on its ecological impacts in freshwater ecosystems remains limited compared to marine environments. Microplastics, defined as particles smaller than 5 mm, have been detected in freshwater systems globally, and their presence is widespread across diverse aquatic habitats. This review examines the sources, distribution, persistence, and ecological consequences of microplastics in freshwater ecosystems, emphasizing their bioaccumulation in organisms from plankton to fish, and the potential risks to human health through microplastic-contaminated fish consumption. Ingestion of microplastics by aquatic organisms can cause physical harm, such as entanglement, and chemical toxicity, including oxidative stress and the accumulation of harmful substances. The trophic transfer of microplastics through the food web raises concerns about higher-level organisms, including humans. Despite these risks, significant knowledge gaps exist regarding the long-term effects of microplastics on freshwater ecosystems. The review calls for improved monitoring, mitigation strategies, and regulatory frameworks to address this issue. Further research is needed to understand the full extent of microplastic pollution in freshwater environments and its impacts on both biodiversity and human health.