The discovery, published in a recent study (pdf) titled “It is raining plastic”, raises new questions about the amount of plastic waste permeating the air, water, and soil virtually everywhere on Earth.

“I think the most important result that we can share with the American public is that there’s more plastic out there than meets the eye,” said Wetherbee. “It’s in the rain, it’s in the snow. It’s a part of our environment now.”

Rainwater samples collected across Colorado and analyzed under a microscope contained a rainbow of plastic fibers, as well as beads and shards. The findings shocked Wetherbee, who had been collecting the samples in order to study nitrogen pollution.

“My results are purely accidental,” he said, though they are consistent with another recent study that found microplastics in the Pyrenees, suggesting plastic particles could travel with the wind for hundreds, if not thousands, of kilometers. Other studies have turned up microplastics in the deepest reaches of the ocean, in UK lakes and rivers and in US groundwater.

More than 90% of plastic waste is not recycled, and as it slowly degrades it breaks into smaller and smaller pieces. Plastic fibers also break off your clothes every time you wash them and plastic particles are byproducts of a variety of industrial processes.

IThough scientists have been studying plastic pollution in the ocean for more than a decade, they can only account for 1% of it. Researchers know even less about the amount of plastic in freshwater and in the air, said Stefan Krause at the University of Birmingham. “We haven’t really started quantifying it,” he said.

Another unknown is whether it would be theoretically possible to flush all plastic out of the natural world, and how long that might take.

Let’s do our best to avoid plastic use and get it out of the environment!