Sorption of Potentially Toxic Elements to Microplastics

In recent decades, plastic pollution has been the focus of environmental research, with particular focus on the distribution and potential effects of a novel emerging contaminant: microplastics. These solid particles of microscopic dimensions which have been found throughout the environment, from mountain tops to the bottom of the ocean, are a reason for concern. Studies so far have mainly assessed baseline concentrations in several environmental compartments (e.g., soil, air, surfacewaters, water column and biota), and as the research field developed, focus has shifted to the interactions between plastics, wildlife, the environment, and human health. Interactions with wildlife either by entanglement, uptake, or ingestion are commonly reported, nonetheless the ecotoxicological effects of microplastic ingestion are not fully understood. The complex relationships and interactions between persistent, bioaccumulative, and toxic chemicals (PBTC) and plastic litter items need to be further assessed. Future research challenges lie on understanding fragmentation and sorption rates of PBTC such as trace metals and persistent organic pollutants (POP) into and/or onto micro- and nanoplastics, but also understanding the effects caused by the leaching of additives into the environment. This chapter highlights the need to conduct ecotoxicological risk assessments that focus on the sorption mechanisms of pollutants into and/or onto plastics, in order to understand potential bioaccumulation mechanisms and the antagonist, synergistic or other relationships of PBTC, plastics, and the environment.