When Melanie Bergmann, an ecologist at the Alfred Wegener Institute in Germany, collected snow and ice samples for her new study, she had to work extra hard not to contaminate them. She and her colleagues always looked for the freshest snow. They always stood with their backs to the wind. They picked up the ice with unorthodox metal tools—including, at one point, a household soup ladle—and deposited it in glassware.
And—most unusually—they always worked with their bare hands, never touching the plastic gloves that most scientists automatically don in the field. “Plastic gloves,” Bergmann told me, “are not the best if you want to sample microplastics.”
In just the past decade, scientists have discovered that microplastics—defined as any plastic detritus that’s about the size of a sesame seed or smaller—are a major new pollutant, the spread of which we’re only now understanding. Microplastics are present in 94 percent of tap water in the United States, according to one study. They form as larger plastic items—toys, clothing, paint chips, car tires—get worn down and torn to shreds.
In a new study, published today in Science Advances, Bergmann and her colleagues looked at whether microplastics collect in the air, as well. They looked for microplastics trapped in snow from the Alps, sea ice from the Arctic Ocean, and snow from the High Arctic island of Svalbard. Snow tends to be good at shaking out particles hanging in the air, so any microplastics in the snow would likely have come from the air, especially in the remote Arctic locations.