In the years since, headlines about the scourge of microplastics have only grown more breathless: We consume a credit card’s weight in plastic every week! But reliable data are, in fact, hard to come by. Imagine streaming a song off your phone’s speakers during a rock concert: You can’t distinguish it from what’s pumping out of the PA. When testing for plastic, the background noise is the nine billion tons of the stuff humans have produced since the 1950s, present in nearly every aspect of our lives. And if we can’t accurately determine how much plastic is in a fillet of fish or a vial of blood, how can we regulate or remediate it?