Microplastics in the Environment

Key Points Polyester fibers make up a majority of microplastic pollution in the oceans. Fibers are likely to have multiple distribution pathways in the environment. There is a need to examine all processes of microfiber generation. Synthetic fabric and textiles continuously shed microfibers during wear.

Key Points Microplastics were found in the marine environment, the freshwater environment, and atmospheric fallout. Microplastics not only act as a source of toxic chemicals but also a sink for toxic chemicals. Fate of microplastics might associate with sedimentation, shore deposition, nanofragmentation, and ingestion. Further research is needed, and what we should do depends on better understanding.

Key Points Microplastic distribution may be greatly altered by global climate change. Incorporating predicted changes into models of plastic transport may enable the prediction of at-risk habitats.

Key Points Ingestion of microplastics by marine species, including bivalves, crustaceans, and fish of commercial importance, is a widespread and pervasive phenomenon, as is the transfer of these contaminants through food webs. Evidence for direct impacts of microplastics on the physiology and health of marine species is growing, and concerns remain regarding their potential role in accumulating, transferring, and delivering doses of harmful pollutants. It is almost inevitable that humans consuming seafood will also be ingesting some level of microplastic pollution, although the possible health implications are only beginning to be considered. Other urgent priorities include harmonization of methods for isolation and analysis of microplastics from biological tissues, to allow reliable investigation of spatial and temporal trends, as well as efforts to identify, control, and, where possible, eliminate sources of plastic pollution.

Key Points Our results suggest that urban runoff contributes microplastics to surface waters in addition to treated effluent. Our findings clarify the potential contribution of secondary microplastics into aquatic environments.

Number of scientific studies identified over the past 8 yr with the word “microplastic” in the title, abstract, or keywords (extracted from the Scopus and Web of Science databases). Word clouds containing the 50 most frequently occurring words in abstracts from 2008 to 2011, from 2012 to 2014, and from 2015 to 2016 are overlaid.