Chelsea Rochman

"Over the last decade, it has become indisputable that small plastic debris contaminates s and wildlife globally. Of concern is that this material, which is ingested by hundreds of species across multiple trophic levels, is associated with a complex mixture of hazardous chemicals. Models, laboratory exposures, and field studies have all demonstrated that plastic debris can act as a source for hazardous chemicals to bioaccumulate in animals. This has been demonstrated with several plastic types, including , (PVC), , and , and for several different organic chemicals, including s, s, , , and . What remains less certain is the ecological importance of this transfer, i.e., the relative contribution of plastic as a source of chemicals to wildlife relative to other sources. ... Further research is warranted to better understand the mechanisms by which plastic-associated contaminants transfer to organisms and if the chemicals are biomagnified in higher trophic level animals leading to ecological consequences or even human health effects via consumption of contaminated seafood."

"Effects from small plastic debris and sorbed chemicals may not be additive and future research is needed to identify the nature of the risks from this combination of s. It is likely that the risk to an will vary by type and size of plastic debris, which may affect its ability to concentrate chemicals from ambient water ... and in s … Risks may also vary over space and time due to the concentration of hazardous chemicals available for ... and the length of time the debris has interacted with ambient water and sunlight. of plastic increases surface area, and may enable greater accumulation of hazardous chemicals. Such complexity begs the initiation of research programs and risk assessments that are ecologically relevant ..."

"For decades we have learned about the physical hazards associated with in the , but recently we are beginning to realize the s. Assessing hazards associated with plastic in is not simple, and requires knowledge regarding s that may be exposed, the exposure concentrations, the types of s comprising the debris, the length of time the debris was present in the aquatic environment (affecting the size, shape and fouling) and the locations and transport of the debris during that time period. Marine plastic debris is associated with a ‘cocktail of chemicals’, including chemicals added or produced during manufacturing and those present in the marine environment that accumulate onto the debris from surrounding . This raises concerns regarding: (i) the complex mixture of chemical substances associated with marine plastic debris, (ii) the environmental fate of these chemicals to and from plastics in our oceans and (iii) how this mixture affects wildlife, as hundreds of species ingest this material in nature."

"Research on (small particles of plastic <5 in size) has long focused on their largest sink: the ocean. More recently, however, researchers have expanded their focus to include freshwater and terrestrial environments. This is a welcome development, given that an estimated 80% of microplastic pollution in the ocean comes from land ... and that rivers are one of the dominant pathways for microplastics to reach the oceans ... Like other , such as s (PCBs), microplastics are now recognized as being distributed across the globe. Detailed understanding of the fate and impacts of this ubiquitous environmental contaminant will thus require a concerted effort among scientists with expertise beyond the marine sciences."