Is It Safe to Eat Snow? What New Microplastics Studies Found

What did the new Sierra Nevada snow study find?

Aleksandra Karapetrova and colleagues at UC Riverside sampled snow across the Sierra Nevada for six months, storm by storm. They collected freshly fallen snow, layers within the snowpack, and dry fallout between storms. Their paper in Environmental Science & Technology went online on October 27, 2026. News coverage followed from the Nevada Current on October 30, Yale Environment 360 on November 2 and The New Lede on November 4.

The headline numbers come in two forms, and they answer different questions. Concentration tells you what is in the snow itself: fresh snow at remote sites averaged 11.8 to 37.5 microplastic particles per liter of meltwater, against 68.3 to 92.9 per liter at the site affected by human activity. Deposition tells you how much lands on the ground: 267 to 3,190 particles per square meter per day at remote sites and 3,242 to 7,480 at the impacted one. Coverage reported that the populated sites included a ski area, and that polyethylene and polypropylene (common in packaging) and polyester (common in clothing) were the most frequent plastics.

Two findings matter for anyone holding a mitten full of snow. Storms that followed longer dry spells carried more microplastics, which suggests particles build up in the air and the next snowfall brings them down. And back-trajectory modeling traced air masses over agricultural and suburban land upwind; the Nevada Current reported that about 70% of tracked storms passed over the San Joaquin Valley. By weight the amount is tiny. Yale e360 put it at less than a tenth of an ounce per acre per day. The study did not measure how much plastic reaches drinking water.

Is there plastic in snow everywhere?

Close to it, in every place researchers have looked. The numbers vary by orders of magnitude, partly because methods differ. Each team counts down to a different smallest size, and smaller particles are far more numerous.

Bergmann and colleagues found microplastics in 20 of 21 snow samples. Varnish, rubber, polyethylene and polyamide (nylon) dominated, and most particles were in the smallest size range the method could see, a sign that many smaller ones went uncounted. In Antarctica, Aves and colleagues found plastic at all 19 sites. PET, the polyester of bottles and fleece, was the most common polymer, and concentrations were higher beside Scott Base and McMurdo Station. Their trajectory modeling suggested some particles could have traveled thousands of kilometers, though they considered local sources more certain.

The 2024 western North America study is the useful bridge to the new paper. Karapetrova’s earlier work found fresh snow near sources carried up to 325 particles per liter, against as little as 5.1 at remote sites, and snow that had sat for months held more than fresh fall. The longer snow sits, the more it collects.

How do microplastics get into snow?

Through the air. Small plastic fragments and fibers from tire wear, clothing, packaging, farm plastics and road paint get lofted by wind and traffic, travel with air masses, and come down with rain or snow. Snow is especially good at catching them: a snowflake has a large, branching surface, and as it falls it sweeps particles out of the air beneath the cloud. That scavenging is why researchers use snow as a natural air sampler. Our airborne microplastics explainer covers the breathing side of the same particles.

Distance from sources sets the baseline. The Nevada Current reported that Karapetrova described local transport from towns 10 to 20 miles away and regional transport from under 50 miles. Tires are a large part of the airborne picture near roads; our tire wear guide explains why. In Bergmann’s study the European samples, which included populated sites in Bremen and Bavaria, ran far higher than the Arctic ones, and rubber and varnish were among the most common particle types.

Is city or roadside snow worse?

Yes, and not only because of plastic. Snow next to traffic soaks up exhaust and road grime. In a Finnish field study, Kuoppamäki and colleagues sampled snowpacks beside roads of different traffic levels. Polycyclic aromatic hydrocarbons (PAHs), suspended solids, phosphorus and most heavy metals were higher beside busy roads and dropped considerably within about 5 meters of the road edge. Snow in urban forest patches had the lowest levels.

A McGill lab experiment shows how quickly this happens. Nazarenko and colleagues placed natural urban snow in a cold chamber and exposed it to diluted gasoline exhaust for one hour. Total organic carbon in the snow rose from 0.218 to 0.539 mg per liter, more than 40 additional organic compounds appeared, and benzene, toluene, ethylbenzene and xylenes climbed from near the detection limit to between about 52 and 380 micrograms per kilogram of snow. That was a chamber test, not a survey of city snowbanks, but it explains why the snow by the curb tastes and looks the way it does.

So is it safe for kids to eat snow?

For an occasional handful of clean fresh snow, the honest answer is that the risk is very small and has not been measured. We found no study that tested health effects from eating snow. What the studies do show is that even remote snow contains tens of microplastic particles per liter of meltwater at the sizes those methods can see, and that roadside snow adds a chemical load on top.

Some scale helps, with a caveat. A study of bottled water by Qian and colleagues estimated about 240,000 particles per liter, roughly 90% of them nanoplastics, using imaging that detects particles below 100 nanometers. Snow studies counted only far larger particles, so the two numbers cannot be lined up as a comparison. What they do suggest is that a mouthful of remote snow is not a unique plastic dose. Plastic particles reach people through water, food and air every day, as our bottled water guide and tap water guide explain. Whether those everyday levels harm health is unsettled; see our health evidence review.

McGill chemist Parisa Ariya, who led the exhaust work, said in 2016 that she did not suggest her own young children eat snow in urban areas (reported by The Washington Post). That fits the evidence: the city part is the concern, not the snow itself.

How to collect snow for snow ice cream or a taste

These steps follow from what the studies measured. They reduce what ends up in the bowl; they cannot make snow sterile or plastic-free.

1. Pick the spot first. An open lawn, field or deck well away from roads, driveways and parking areas. In a city, a backyard beats a front yard.
2. Wait until it has been snowing a while. Our inference from how scavenging works is that the first flakes clean the most out of the air. The Sierra study supports the direction: storms after long dry spells carried more plastic.
3. Take only the top few centimeters of fresh, white snow on the day it falls. Leave the layer touching the ground.
4. Use a clean metal or glass bowl and spoon, set it out or scoop into it directly, and skip plastic buckets and sand toys.
5. Keep it small and occasional. Snow ice cream once or twice a winter is a different thing from melting snow as drinking water.
6. Don’t melt snow to drink unless you have to. In the backcountry, treat snowmelt as untreated surface water: boil or filter it as you would stream water.

Does melting or boiling snow get rid of microplastics?

Melting changes nothing: every particle in the snow is now in the water. That is exactly how the studies count them, as particles per liter of meltwater. Boiling is for germs. It makes untreated water safer to drink from a microbial point of view, but none of the snow studies tested whether boiling changes the plastic count, so we would not rely on it for that. A pot of melted snow on a camp stove is still surface water that picked up whatever was in the air.

Older snow is worth avoiding for a second reason. In Karapetrova’s 2024 study, summer surface snow that had sat for months held 57.5 to 539 particles per liter, and layers sampled at depth in the snowpack ranged from 35 to 914. A snowbank that has been through a few thaws and refreezes has been collecting dust, soot and particles the whole time. Fresh fall is the cleaner end of the range, not a clean product.

What to tell kids who love eating snow

Fear is the wrong lesson. A child who catches flakes on their tongue during a walk in the park is doing what children have always done, and nothing in these studies suggests that moment is dangerous. The useful lessons are simple and easy to remember: white and fresh only, never from the side of the road or the plow pile, never from the ground where the dog walks, and ask a grown-up before eating snow from somewhere new. Those rules cut out the snow with the most traffic pollution and the most obvious dirt, which is where the evidence points.

If your child is sick, has a weakened immune system, or you are somewhere with heavy industry or wildfire smoke nearby, skip it. Those situations were not studied either, and the cautious choice costs nothing.

Use the App

Snow is out of your hands. The bottle and the bowl aren't.

Scan the water bottle, lunch container or kids' cup you use every day. The app records its declared materials, flags plastic parts that touch the drink, and saves a lower-plastic swap.

Does plastic in snow end up in drinking water?

Snowmelt is a major water source in the West. The California Department of Water Resources says that, on average, the snowpack supplies about 30% of the state’s water needs, which is why it calls the snowpack a frozen reservoir (DWR, April 2026). Coverage of the Sierra study noted the snowpack also supplies about 60% of northern Nevada’s fresh water.

That does not mean the numbers in snow are the numbers in your tap. Meltwater runs through soil, streams and reservoirs, and most utilities treat it before it reaches homes. The Sierra authors did not measure how much plastic reaches drinking water, and nobody can infer a tap-water count from a snow count. What the study does show is a steady input to the watershed that will need monitoring. If you want to reduce what comes out of your own tap, our water filter guide compares the options that have published particle data.

What the evidence does not establish

• A safe or unsafe amount of snow to eat. No reviewed study tested ingestion or health outcomes.
• A count per mouthful. Deposition per square meter is not a concentration, and snow density varies, so we have not converted it.
• Nanoplastics in snow. Karapetrova told reporters there are no verified methods yet for measuring nanoplastics in these samples, so true counts may be higher.
• Cross-study rankings. Arctic, Alpine, Antarctic and Sierra numbers used different size cutoffs and methods.
• Tap-water levels from snow levels. Treatment and transport change what reaches homes.