Plastic Currents: Distribution, Fate, and Risks of Micro- and Nanoplastics in Freshwater Systems

Plastic pollution presents a significant and complex environmental challenge worldwide, impacting terrestrial, freshwater, and marine ecosystems. In freshwater systems, plastic debris is transported through rivers, lakes, and wetlands, influenced by hydrological and land-use factors, and can act both as sinks and sources of pollution. Microplastics (MPs) and nanoplastics (NPs) are increasingly recognized as emerging pollutants, originating from the breakdown of larger plastics or direct manufacturing processes. These tiny particles pose risks to both marine and terrestrial ecosystems, as well as potentially to human health. This chapter provides a comprehensive overview of the plastic pollution crisis, particularly regarding MPs and NPs, highlighting their pervasive nature and complex origins. Furthermore, it elaborates on the diverse origins of plastic debris, noting that pollution is not confined to urban areas but extends to remote regions, such as the Arctic and mountaintops, and results from various sources, including tire wear from traffic, household activities, synthetic textiles, and industrial processes. Analytical techniques, such as micro-FTIR and chromatography, are crucial for detecting and characterizing these pollutants; however, significant knowledge gaps remain, particularly regarding the long-term health impacts and the behavior of MPs and NPs in the environment. The chapter advocates for a multifaceted approach that integrates technological innovation, policy measures, international cooperation, and public awareness to combat plastic pollution effectively. It underscores the necessity of transforming production, consumption, and waste management paradigms to safeguard ecosystems and human health from this pervasive threat.