Microplastics in Freshwater Environments: Sources, Fates and Toxicity

Plastic debris at micro- and nanoscales has been detected in widespread aquatic environments. Accordingly, microplastics primarily pose serious threats to freshwater ecosystems, causing physical and histophysiological damage similar to that in marine environments. The sources, fates, and toxicities of microplastics in freshwater ecosystems are detailed in this review. Additionally, microplastics serve as vehicles, and therefore, the action modes of the combined toxicity of microplastics with other pollutants in biota are discussed in freshwater environments. Finally, the knowledge gaps regarding microplastics that exist between laboratory and realistic environmental studies, such as the sizes, shapes, colors, "ages," and types of microplastics, are identified for extrapolating laboratory findings to natural aquatic ecosystems. To establish management strategies and assess the environmental risks of MPs in freshwater systems, the sources, fates, and toxicities of microplastics in freshwater environments, particularly in drinking water source areas, should be considered seriously and require future in-depth investigation.