The Impact of Microplastic Footprints in Developing Countries: Threats to Ecosystems, Human Health, and Catalysts for Climate Change

Abstract

Microplastics, defined as plastic particles smaller than 5 mm, are emerging environmental pollutants with increasingly significant global impacts, particularly in developing countries where waste management and pollution control remain challenging. This systematic review examines the occurrence and distribution of microplastics in aquatic ecosystems and evaluates their potential implications for ecological systems, human health, and climate change. Microplastics have been detected in major rivers across Asia and Africa at concentrations ranging from 0.5 to more than 3,000 particles/m³. Their ecological impacts include adverse effects on plankton, shellfish, and fish, as well as potential alterations in sediment dynamics, food webs, and biogeochemical carbon cycling. Human exposure may occur through multiple pathways, including seafood consumption, fish-derived products, sea salt, and drinking water, raising concerns regarding potential long-term health risks. Moreover, microplastics in aquatic environments may influence greenhouse gas dynamics, including the release of methane (CH₄) and ethylene (C₂H₄), while potentially reducing plankton-mediated carbon sequestration. These interconnected effects highlight the need for integrated mitigation strategies addressing plastic pollution, ecosystem degradation, human exposure, and climate-related impacts.