Occurrence, fate, and sorption behavior of contaminants of emerging concern to microplastics: Influence of the weathering/aging process

Microplastics have been observed in most environments, and their concentrations are expected to increase over the coming decades given the continued and increased production of synthetic polymer products. The expected increase in microplastic pollution may elevate the risk posed by these synthetic particles to the health of both the aquatic environment and humans. This review seeks to provide a current overview of the occurrence, fate, and impacts of microplastics in aquatic environments worldwide. We first summarize studies recording the occurrence of representative microplastics in marine and freshwater environments, revealing the sources and composition of microplastics. Then, the sorption behavior and relationship between microplastics and pollutants are discussed. The influence of the weathering/aging process and environmental factors on sorption behavior in laboratory tests and real environments is reviewed with particular emphasis on contaminants of emerging concern (CECs). Finally, the potential toxic effects of microplastics on aquatic biota and human health are discussed. This review aims to advance our understanding of the fate and impacts of microplastics in aquatic environments and to shed light on important questions warranting further investigation.