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Danny Katz, left, CoPIRG Foundation executive director and Lexi Kilbane, Environment Colorado intern from the University of Denver, stand at the waterÕs edge of the South Platte River in Confluence Park, to discuss a new report from the research they have performed finding micro plastics in 100% of the water they tested in sixteen different sites. The two demonstrate their sample collection-using a simple mason jar. (Kathryn Scott, Special to The Colorado Sun)

Lexi Kilbane knew, in a vague, nonscientific way, that plastic pollution was a growing problem, and that tiny shards of plastics were showing up everywhere a microscope might look. 

But the magnitude of the contamination finally hit home after she dipped a water testing kit into a City Park lake, right near her house, and filtered the sample. Fibers from shredded tarps, jackets and carpet popped into view, in a dystopian kaleidoscope. 

“There’s no mistaking that for a natural particle,” said Kilbane, a University of Denver graduate student and microplastics project manager for Environment Colorado Research and Policy Center. 

“Unless you’re a fish, of course,” Kilbane added. “It was stunning that someone like me, without any sort of background in this, could plainly see the issue in front of my eyes.” 

CoPIRG and partners sampled water in 16 Colorado locations from Monument Creek to the Arkansas and South Platte Rivers, and found microplastics in all samples. (Provided by CoPIRG)

Using national protocols for detecting microplastics, Kilbane and the nonprofit advocacy group CoPIRG sampled 16 waterways in Colorado and found the plastics pollution in every one. They are sharing results of their study with national sampling networks, and urging Colorado policymakers to double down on recent efforts to slow use of plastics that deteriorate into dangerous particles but never biodegrade. 

“They’re going to be in our environment, for hundreds and hundreds of years,” CoPIRG director Danny Katz said. The Colorado Legislature has taken action in banning certain single-use consumer plastics like plastic bags, with more rules kicking in Jan. 1, but local governments and consumers must do more, he said. 

“Clearly given how much microplastic we’re finding and how many other sources are out there, from clothing to packaging, to things like straws and utensils, there’s more action that needs to be done,” Katz said. 

Studies around the world, from Asian lagoons to Colorado’s high country snowpack, are showing there’s no escape from potential environmental impacts of ubiquitous, petroleum-based plastics. Production, industrial use and consumer handling of plastics makes the material shed particles and fibers 5 mm or less in size. The pieces that studies filter out range from the size of a sesame seed to particles too tiny for the human eye to detect. 

Researchers from the U.S. Geological Survey in Colorado and the Center for Snow and Avalanche Studies started finding microplastics when they were analyzing blown-in dust in mountain snowpack. They focused on the plastics, and in dozens of samples from water years 2015 and 2016, found the frequency of microplastics at 11 Upper Colorado River Basin sites was greater than in 2013 and 2014.

Back at the CoPIRG Foundation offices in lower downtown, a small pile of Petri dishes used for the groupÕs testing and report, line the tables in their citizen science lab. (Kathryn Scott, Special to The Colorado Sun)

Meanwhile, plastics production only increases. 

“The world produced 348 million metric tons of plastic in 2017, and this number grows every year by about 5%,” Utah researchers said in a study published in the journal Science in 2020. “A large proportion of this production accumulates as waste in the environment, and progressive fragmentation” sends the microplastics abroad on the wind, the study said.

“Eleven billion metric tons of plastic are projected to accumulate in the environment by 2025,” they add.

Researchers are concerned that microplastics enter the food chain, and that little is known so far about impacts on wildlife or humans who ingest the materials. Fish consume the plastic, intentionally or not; other wildlife consume the fish, or drink from tainted waterways. Cattle drink from streams and ponds. Plants may take up the tiniest microplastics through their roots. 

“As a headwater state, we need to reduce the amount of plastic that flows out of our borders and protect our wildlife and ecosystems here in Colorado,” Kilbane said, at a news conference May 25 at the confluence of the South Platte River and Cherry Creek, where some of the study samples were taken. 

CoPIRG outlined several steps by Colorado lawmakers that may help start a reduction in plastics pollution in the state: 

  • Requiring consumers to pay for plastic bags at large retailers in 2023, and banning the plastic bags altogether on Jan. 1, 2024. 
  • Polystyrene, or styrofoam, plastic food containers used in fast food and takeout retailers are banned starting Jan. 1, 2024. 
  • Removing state restrictions on local governments passing more stringent bans and recycling than covered in state law. Some Colorado cities have moved to reduce or ban more single-use plastics, such as plastic utensils in retail settings. 

Less than 10% of consumer plastics are actually recycled, studies show, despite municipal recycling programs encouraging the adding of used plastics into recycling bins. Even the recycling process can produce dangerous microplastics, a recent study showed, through the abrasion and deterioration of plastics in the handling process that are then blown or washed into the environment. 

Back at the CoPIRG Foundation offices in Lower Downtown Denver, Lexi Kilbane, Environment Colorado intern from the University of Denver, joins East High School junior Gabe Curcio, 17. The two take the water sample Kilbane just collected from the South Platte River that they poured through a filter and then they placed the filter under a digital microscope. A microplastic fiber from their water sample was visible on their computer screen (black, squiggly line about 2/3 up on the screen). (Kathryn Scott, Special to The Colorado Sun)

CoPIRG and others are focusing attention on reducing first-time plastics use, whether through reusable cloth grocery bags, or consumers bringing their own reusable containers to retail food and goods outlets. Starbucks recently announced that Colorado consumers could bring reusable coffee mugs for their drinks ordered at drive-throughs for a limited time, in addition to indoor store counters. 


Katz would like to see more local governments allowing consumers to bring their own containers to food retailers for takeout, though such practices might require coordination with local health departments. There are also consumer goods stores that provide bulk refills of items previously shipped in plastic, including shampoo and cleaning products, Katz said. 

“There’s lots of ways that consumers can be part of the solution,” he said. 

Michael Booth is The Sun’s environment writer, and co-author of The Sun’s weekly climate and health newsletter The Temperature. He and John Ingold host the weekly Sun-Up podcast on The Temperature topics every Thursday. He is co-author with...