SOURCE: High Country News

DATE: September 10, 2018

SNIP: TO THE EXTENT THAT most of us think about microplastics, we’re probably familiar with microbeads, the tiny plastic scrubbers that became common in face washes and toothpastes in the late 1990s. Following a surge in public awareness about the dangers microbeads pose when eaten by fish and other wildlife, Congress voted to ban them in personal care products beginning in 2017. But Danielle Garneau, an associate professor of environmental science at SUNY Plattsburgh who studies microplastics, says that microbeads never made up a large percentage of the microplastics she and her colleagues found in freshwater. A bigger culprit, she says, are plastic fibers. Head to any coffee shop in Bozeman on a wintry Saturday morning, and the problem is in plain sight. Fleece pullovers. Polypropylene leggings. Polyester hats. Globally, production of synthetic fibers — long, thin strands of plastics spun into threads much as wool is spun into yarn — more than doubled from 2000 to 2017. Today, roughly 58 percent of clothing is woven with them, including many technical outdoor fabrics. While these fabrics excel at keeping us warm and dry in the elements, they shed every time they’re washed: up to 250,000 plastic fibers per jacket, per wash cycle.

IF FUTURE SCIENTISTS digging through layers of rock and sediment come upon the geologic strata being set down today, they’ll find a colorful stripe of earth atop the plain rock and dirt of the pre-industrial era. Since plastics first became widespread in the mid-20th century, more than 9 billion tons have been manufactured, most of which has been thrown away.

Once they’re buried, scientists have no reason to believe that these Crayola-colored bits and bobs will ever fully biodegrade. Instead of calling our current geologic epoch the Anthropocene, or Age of Humans, scientists who study plastics sometimes refer to it as the Plastocene. Geologists even recognize a type of rock — “plastiglomerate” — that’s made from plastic and sediment that have naturally fused together.

So perhaps it should come as no surprise that when Egnew and Paulus turned in their water bottles, together with more than 700 additional samples collected from 72 sites along the Gallatin over a two-year period, the samples were flush with tiny pieces of plastic. In peer-reviewed research soon to be published, Barrows found that 57 percent of the samples contained microplastics, with an average of 1.2 pieces per liter of water. If that doesn’t sound like much, consider that the Gallatin flows at a rate of 6,000 cubic feet of water per second at its peak, and this seemingly clear mountain river begins to look like a conveyor belt for tiny pieces of trash.

Microplastics have been found in numerous other Western water bodies, from alpine tarns to the giant reservoir of Lake Mead. But the upper Gallatin is one of the most pristine watersheds in the Lower 48 — a playground for fly fishermen, whitewater boaters, mountain bikers and hikers. Much of the river flows through protected public lands. So where’s the plastic coming from?

One source could be the outdoor recreation industry. Mixed in with the organic material floating in the river water, Barrows finds shreds of synthetic rubber like that used in mountain bike tires, the neoprene used in wetsuits, and the PVA used in fishing line. It’s intriguing, she says, “to have the materials from your study directly point to the land uses in a particular area.”