Plastics have become ubiquitous in natural and built environments which has caused concern regarding potential harms to human and aquatic life. Microplastics (plastic particles ranging in size from 5 mm to 1 nm) and nanoplastics (plastic particles smaller than 1 nm) have been found in every ecosystem on the planet from the Antarctic tundra to tropical coral reefs. The wide range of particle sizes, densities, and compositions pose a challenge for researchers because there is not a single method that can be used to characterize the wide variety of micro and nanoplastic particles. There is a pressing need to develop and standardize collection, extraction, quantification, and identification methods for micro/nanoplastics to improve reliability, consistency and comparability across studies.
EPA research addresses plastic pollution in the aquatic environment by establishing reliable and reproducible approaches for sampling micro/nanoplastics, separating plastics from organic and inorganic interferences found in environmental samples, and extracting plastics without harsh chemicals or heat that further degrade plastic. Using state-of-art analytical chemistry instrumentation, researchers are working to determine appropriate analytical methods to characterize and quantify total microplastics in sediment and water samples, as well as the different types of plastic polymers. This research helps inform recommendations for best practices and standardized methodologies to characterize and assess the extent of micro and nanoplastics pollution in water.