Clean Wisconsin says mounting evidence shows these tiny plastic particles are becoming more numerous in the Great Lakes. Microbeads are used in body scrubs and toothpaste. They can pass through wastewater treatment plants and enter waterways, aquatic life and human bodies. Once there, they keep adding up because they don’t easily break down. Recent research suggests an average of 17,000 microbeads per square kilometer in Lake Michigan. Their chemicals can harm digestive systems of fish, cause other abnormalities and also pose problems higher up the food chain. We join Clean Wisconsin in applauding legislation to halt their use. Two Republicans, Sen. Rob Cowles of Green Bay and Rep. Mary Czaja of Irma, are seeking cosponsors for bills based on a 2014 Illinois law. The legislation would require manufacturers to phase out their use.