From Fish to Humans, A Microplastic Invasion May Be Taking a Toll

From Fish to Humans, A Microplastic Invasion May Be Taking a Toll

Andrea Thompson

Mark Browne had a suspicion. He hoped the samples of dried blood taken from a blue mussel and placed under a special microscope would tell him if he was correct. As a fuzzy, three-dimensional image of the mussel’s blood cells appeared, there they were, right in the middle—tiny specks of plastic.

Whereas photos of sea turtles eating plastic bags have become the poster child of the environmental harm wrought by humanity’s plastic waste, research like Browne’s illustrates the scope of the problem is far larger than the trash we can see. Tiny pieces of degraded plastic, synthetic fibers and plastic beads, collectively called microplastics, have turned up in every corner of the planet—from Florida beach sands to Arctic sea ice, from farm fields to urban air.

Their size—from about five millimeters, or the size of a grain of rice, down to microscopic—means they can be ingested by a wide range of creatures, from the plankton that form the basis of the marine food chain to humans. As Browne’s 2008 study was one of the first to demonstrate, those plastic particles don’t always pass harmlessly through the body. The finding “was one of those sort of bittersweet moments,” the ecotoxicologist at the University of New South Wales in Sydney says. “You’re pleased that some prediction you’ve made has come true—but then you’re devastated” because of the potentially profound ecological implications.