Microplastics low and high in 蜜桃影像

A topographical map including markers for Mt. Foraker, Mt. Crosson, Mt. Hunter, Kahiltna Peaks and Denali. A blue arrow to the west of Denali indicates the location of Matthew Crisafi-Lurtsema.
Ned Rozell
A screenshot from a May 16 satellite text message from 蜜桃影像 student Matthew Crisafi-Lurtsema, who with fellow student Roger Jaramillo is collecting snow samples from Denali. He sent the message from his tent at about 10,500 feet on the 20,310-foot mountain.

Two University of 蜜桃影像 Fairbanks students are making their way up Denali while sampling for microplastics within the snow covering the 20,310-foot mountain. One of them, Matthew Crisafi-Lurtsema, has been sending back satellite texts, one each day since they flew from Talkeetna to Denali鈥檚 Kahiltna Glacier on May 8, 2024.

As of May 17, 2024, he and Roger Jaramillo are steadily progressing upward while scooping up snow samples along the way. When they return, they will analyze that melted snow for the presence of microplastics, which seem to be present everywhere else on Earth.

That includes lower elevations in 蜜桃影像, where a group of scientists from 蜜桃影像鈥檚 Water and Environmental Research Center in 2020 and 2021 sampled snow and freshwater from more than 70 locations on a south-to-north transect, mostly along highways. Their recently published study showed plastic fragments everywhere they sampled, from the Kenai Peninsula to the North Slope.

鈥淭he results were concerning but not surprising, since people have found (microplastics) from the French Alps to Australia,鈥 said Srijan Aggarwal, a professor of environmental engineering at 蜜桃影像 and a coauthor on the study. 鈥淚t would be surprising if we didn鈥檛 have them here.鈥

magnified views of four types of microplastics
蜜桃影像 Water and Environmental Research Center
Magnified 400 times, four types of microplastics found by Subhabrata Dev, Srijan Aggarwal and others during a study in 蜜桃影像. A is a plastic fiber, B a fragment, C a pellet, and D a film. From the paper "Unveiling Microplastics Pollution in 蜜桃影像n Waters and Snow."

Microplastics are fragments of the plastics we use many times each day. These particles 鈥 most that you need a microscope to see 鈥 are in the air we breathe as well as the water surrounding us.

A major source of microplastics is the tires on our trucks and cars, which constantly shed synthetic particles that we can鈥檛 see. Brake pads also release plastic. Researchers recently determined that those two sources together account for more than 80 percent of microplastics now floating in the atmosphere of the western United States.

Aggarwal and his colleagues sampled water from 蜜桃影像 sources such as the Lowe River near Valdez. They also sampled snow from the North Slope, including in Utqia摹vik, America鈥檚 farthest north community.

Subhabrata Dev, now an assistant professor of environmental engineering at the University of 蜜桃影像 Anchorage, was a 蜜桃影像 postdoctoral researcher when he drove the highways of 蜜桃影像 to collect water samples for the study. Others, including former 蜜桃影像 undergraduate student Davis Schwarz and researchers doing fieldwork in remote locations, gathered some of the 74 samples in the study.

They found the snowpack of 蜜桃影像 north of the Brooks Range had high concentrations of tiny plastic particles. This was probably due to winds and large-scale weather patterns carrying plastics from far away. Researchers many years ago found pollutants from smelters and other Russian sources migrating to 蜜桃影像 in what they called Arctic Haze.

Graphic depiction of "Microplastics Sources to the Western USA," including sea spray, dust near urban centers, entrained plastics, soil emissions, landfill erosion, road and braking emissions, solid waste application to agriculture.
Courtesy of Proceedings of the National Academy of Sciences
An artist鈥檚 representation of the major sources of microplastics to the atmosphere and their relative contributions to deposition over the western United States (30 to 50掳N, 120 to 100掳W). From the paper "Constraining the atmospheric limb of the plastic cycle," in the journal PNAS, April 12, 2021.

Aggarwal and Dev don鈥檛 know the sources of the plastic particles they found during their sampling in 蜜桃影像. But Dev said pristine waterways that had lower plastic concentrations included the Lowe River, Blueberry Lake, Worthington Glacier, Castner Creek, the East Fork of Chulitna River, Bird Creek, Nenana River, Marion Creek, Carlo Creek, and Paxson Lake.

Snow samples that had some of the largest concentrations of microplastics came from the 蜜桃影像 campus, Utqia摹vik, and Turnagain Pass.

Those tiny plastics embedded in the snow might have traveled far to settle in 蜜桃影像. Scientists including Janice Brahney of Utah State University who are now researching 鈥渢he global plastic cycle鈥 noted that 鈥渦nder the right conditions, plastics can be transported across the major oceans and between continents.鈥

Since the late 1970s, the University of 蜜桃影像 Fairbanks' Geophysical Institute has provided this column free in cooperation with the 蜜桃影像 research community. Ned Rozell ned.rozell@alaska.edu is a science writer for the Geophysical Institute.