Researchers Marcus Eriksen and Anna Cummins were taking water samples from Lakes Erie, Huron, and Superior in 2012 when they noticed something puzzling—millions of plastic beads, each one smaller than a grain of sand. The California couple had spent years researching the Great Pacific Garbage Patch and studying plastic pollution in the world’s oceans. They were finding much of the same debris in the Great Lakes—bottles, bags, straws, caps, and countless other single-use plastics—but they were stymied by the vast amount of mysterious plastic beads in every trawl. After some research, Eriksen says, they realized the spherical particles were “the same size, shape, texture, and color of the microbeads you find in consumer beauty products”—facial scrubs, cleansers, and other common products that leave our skin clean but also send millions of plastic particles down the drain. The beads are so tiny that most pass right through our sewer systems and into rivers, lakes, and oceans, where they accumulate—a single tube of Johnson & Johnson’s Clean & Clear facial scrub can contain u …