Science & Tech · Science & Environment · 6 hrs ago
Microplastics found in snow across California’s Sierra Nevada
Researchers found microplastics at all seven sites where they sampled snow during storms in California’s Sierra Nevada.
The sites included remote mountain locations far from roads, as well as the Mammoth Mountain ski area.
Snowfall carried more plastic particles than dry weather, because falling snowflakes collect particles from the air.
Remote sites received 270 to 3,200 particles per square meter per day during the height of storms, while one Mammoth Mountain site received 2,600 to 7,500.
Airborne plastics reached even isolated mountain areas, though the study could not identify their exact origins.
Most of the air masses sampled had passed over Fresno and Madera counties, suggesting the Central Valley may be one source.
The findings matter for California’s water supply because the Sierra Nevada snowpack provides about 30% of the state’s freshwater, and the researchers measured plastic entering it with snow.
Scientists found microplastic particles at all seven Sierra Nevada sites sampled during snowstorms.
Remote sites received an estimated 270 to 3,200 particles per square meter per day.
At a Mammoth Mountain ski-area site, deposition was estimated at 2,600 to 7,500 particles per square meter per day.
The Sierra Nevada snowpack supplies roughly 30% of California’s freshwater.
Researchers traced most sampled storm air masses over Fresno and Madera counties, but could not pinpoint the particles’ exact origins.
- Who
- A research team led by Aleksandra Karapetrova, an environmental toxicologist at the University of California, Riverside.
- What
- Scientists found microplastic particles in snow at all seven sampled sites during snowstorms.
- When
- During active snowstorms; the study dates are not stated.
- Where
- Seven locations across California’s Sierra Nevada, including remote sites and a site in the Mammoth Mountain ski area.
- Why
- The study measured plastic deposition during individual storms and examined the air masses bringing particles to the mountains.
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- Sampling sites
- Seven locations across the Sierra Nevada
- Remote-site deposition
- 270 to 3,200 particles per square meter per day
- Mammoth Mountain deposition
- 2,600 to 7,500 particles per square meter per day
- Freshwater supply
- Sierra Nevada snowpack provides roughly 30% of California’s freshwater
- Air-mass routes
- Most sampled storm air masses passed over Fresno and Madera counties
What people are saying
But no matter how far out the site, I always found microplastics there.
I didn’t think the plastics would stay suspended so much in the town.