Plastic Microbead Accumulation in Our Freshwaters: North American Great Lakes Assessments and Perspectives

Plastic microbeads, widely incorporated into personal care and cleansing products, have emerged as a pervasive contaminant in freshwater systems, including in North America. Historical estimates indicate that North American consumers alone contributed trillions of microbeads daily to municipal wastewater, with global usage reaching quadrillions per day. Regulatory actions in 2017 in Canada and the USA to ban microbeads in personal care products appear to have greatly reduced microbead contamination levels, including a decrease in microbead proportion from 2 to 5% to 0.003%, and an 86% reduction in PE microbead discharge from wastewater treatment plants. Yet these particles still persist in the environment due to their resistance to degradation and continued release from unregulated sources, including industrial abrasives and certain cleaning agents. Studies across the Great Lakes, one of the world’s largest freshwater systems, have documented widespread microbead contamination in surface waters, sediments, and shorelines, highlighting their persistence and accumulation. This review synthesizes findings from key studies conducted between 2013 and 2017 to establish a pre-ban baseline of microbead distribution in the Great Lakes, and presents new data collected from 2018 to 2021 as a post-ban contamination assessment. The review emphasizes the unique challenges posed by microbeads within the broader context of microplastic pollution. We also hope that this paper underscores the critical role of polymer chemists and engineers in developing innovative materials and removal strategies to mitigate future contamination.