Scientist discovers plastic rain over America’s Rocky Mountains

Plastic was the furthest thing from Gregory Weatherbee’s mind when he began analysing rainwater samples collected from the Rocky Mountains. “I guess I expected to see mostly soil and mineral particles,” said the US Geologic Survey researcher. Instead, he found multicoloured microscopic plastic fibres.

The discovery, published in a recent study titled “It is raining plastic”, is raising 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 Weatherbee. “It’s in the rain, it’s in the snow. It’s a part of our environment now.”

Rainwater samples collected across Colorado and analysed under a microscope contained a rainbow of plastic fibres, as well as beads and shards. The findings shocked Weatherbee, 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 France’s Pyrenees Mountains, suggesting that plastic particles could travel with the wind for hundreds, if not thousands, of kilometres. Other studies have turned up microplastics in the deepest reaches of the ocean, in UK lakes and rivers and in US groundwater.

A major contributor is trash, said Sherri Mason, a microplastics researcher and sustainability coordinator at Penn State Behrend. More than 90 per cent of plastic waste isn’t recycled, and as it slowly degrades it breaks into smaller and smaller pieces. “Plastic fibres also break off your clothes every time you wash them,” Mason said, and plastic particles are by-products of a variety of industrial processes.