Microplastics entering northwestern Lake Ontario are diverse and linked to urban sources. (1st May 2020)

• Record Type: Journal Article
• Authors: Grbić, Jelena; Helm, Paul; Athey, Samantha; Rochman, Chelsea M.
• Is Part Of: Water research. Volume 174(2020)
• Publication Date: 2020-05-01
• Subjects: Microplastic -- Great lakes -- Source apportionment -- Runoff -- Wastewater; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2020.115623
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: The sources of microplastics and other anthropogenic particles in freshwater are not well understood. The Greater Toronto Area, Canada's most populous urban area, offers a great study area for understanding the sources and pathways for microplastics to enter freshwater ecosystems. Here, we quantified and characterized microplastics and other anthropogenic particles from Lake Ontario surface waters and source waters (including stormwater runoff, agricultural runoff, and treated wastewater effluent) to better understand sources to the Great Lakes. Anthropogenic particle concentrations in lake samples were 0.8 particles L −1 . In source waters, average concentrations were relatively higher in stormwater and wastewater, with 15.4 particles L −1 and 13.3 particles L −1, respectively, compared to 0.9 particles L −1 on average in agricultural runoff. Source waters revealed distinct signatures related to the morphologies of anthropogenic particles, e.g., fibers in wastewater. In addition, many upstream watershed characteristics were found to be significant predictors of anthropogenic particle concentration. Proximity to urban areas were positively correlated to anthropogenic particle concentrations. Future studies should focus on local source-apportionment to inform management and prevent further contamination of microplastics to freshwater ecosystems. Graphical abstract: Image 1 Highlights: Microplastics were found in treated wastewater and agricultural and urban runoff. Source waters had unique communities of microparticles that varied by morphology. Proximity to urban areas was positively correlated with microplastics.