“Great Lakes' latest pollution threat is 'microplastics'” is an August 12, 2019 Star Tribune story. It notes that the discovery of microplastic in lake water “… has prompted researchers at the University of Minnesota, Duluth to expand testing to other Minnesota lakes and the fish that inhabit them. The exact source of the microplastics remains something of a puzzle, and it’s not clear yet how to gauge their impact on people, aquatic life and the environment … ‘Depending on the chemistry of the particles, they not only enter the food web, but they could also absorb other pollutants, and those pollutants could also enter the food web,’ said Kathryn Schreiner, the university environmental chemist leading the project … The Health Department has just begun to examine the question, a spokesman said …”