Eating freshly fallen snow, often referred to as the “first snowfall,” is a practice that many people enjoy, especially children. Fresh snow has a clean, crisp taste that is unlike snow on the ground which picks up dirt and debris. However, many people wonder if it is safe or healthy to ingest the first snowfall. There are a few factors to consider when deciding whether or not to eat new fallen snow.
Is newly fallen snow clean?
In general, the first snowfall is relatively clean and free of major contaminants. Snow forms high up in the atmosphere, far removed from pollution sources like smog or car exhaust. As snow falls to the earth, it has little opportunity to gather significant pollutants on its way down.
However, some air pollution can get trapped in the snow crystals as they form. One study found that snow can contain low concentrations of toxins like PCBs and pesticides that become integrated into the ice crystals during formation. Levels of these pollutants, however, are typically minute in new snowfall.
The main risk of contamination comes when the snow reaches the ground. Once on the earth, snow quickly starts accumulating whatever is on the surface – dirt, microplastics, bird droppings, etc. Time sitting on the ground allows more accumulation of impurities. The first snowfall has less exposure to these contaminants compared to snow sitting for days or weeks.
So while not 100% pure, fresh snowfall contains very low levels of pollutants, especially in areas with less air pollution. Risk is lowest eating snow that comes straight from the sky, versus snow that has touched the ground.
Is snow safe to eat in urban areas?
In densely populated cities, the snow may collect more airborne contaminants during its journey from the cloud to the ground. Exhaust particulates and industrial emissions can get swept up into the snowfall over urban centers.
However, research suggests snow in cities still has relatively low levels of contaminants that pose a health risk. One study in Montreal, Canada tested snow near major highways and industrial areas and found minimal contamination. Even snow collected right next to busy roads showed very little accumulation of toxins like lead and cadmium.
Another study in New York looked at lead levels in freshly fallen snow and snow on the ground. Both types of snow had very low lead content throughout the city. Central Park snow showed slightly higher lead levels than residential neighborhoods, suggesting some concentration of pollutants in high traffic areas. Still, the lead content was far below the safe limit for drinking water standards.
While snow may pick up minimal contaminants in the air over cities, research shows it does not reach harmful levels, even in urban centers. The first snowfall should pose minimal health risks in most cities. However, it’s still best to avoid eating snow right next to major roads whenever possible.
Does snow contain bacteria or viruses?
A common concern with eating snow is ingesting bacteria, viruses, or other microorganisms. However, most pathogens need a host to survive and cannot live for extended periods in snow or icy conditions. Research shows that fresh snow has very low microbial content.
One study in Quebec tested snow for bacterial indicators like E. coli. They found an absence of fecal bacteria in freshly fallen snow, even in urban areas. Viruses and parasites also do not likely survive in snowy conditions. Cold temperatures, UV rays, and lack of nutrients make snow an inhospitable environment for most pathogens.
However, one exception is norovirus. Researchers have found that norovirus may be able to persist in winter conditions. The viruses can bind to snowflakes and travel in the air within snow before settling to the ground. Norovirus outbreaks do spike in winter months, which may suggest snow can harbor infectious particles under specific conditions.
While most pathogens do not survive in snow, ingesting snow in areas frequented by animals still carries some minimal risk. Snow can pick up traces of bacteria, viruses, or parasites from animal droppings, though amounts are typically very low in freshly fallen snow. Those with weakened immune systems may want to avoid consuming snow in regions with high animal populations as a precaution.
Does snow have nutritional value?
Snow is primarily composed of water, making it non-caloric and void of vitamins or minerals. However, research suggests freshly fallen snow may contain small amounts of nitrogen.
One study found that snow samples from southern Ontario contained low levels of inorganic nitrate, around 0.2 to 2.7 parts per billion. Nitrates come from nitrogen dioxide in the atmosphere binding with water molecules during ice crystal formation.
While present only in trace amounts, nitrates are considered beneficial nutrients. The nitrates contained in snow are equivalent to nutrients found in green, leafy vegetables. Nitrates promote heart health and boost exercise performance by dilating blood vessels.
Despite containing minute levels of nitrates, snow should not be considered a significant source of nutrients. The small nitrate concentrations are likely negligible compared to a balanced diet.
Does snow have benefits as a source of clean water?
In winter survival situations, melted snow can provide a source of hydration when no other clean water is available. Snow is primarily just frozen water, so melting it yields plenty of life-sustaining fluids.
Snow is even recommended over ice as an emergency water source. Melting snow results in more usable water and requires less heat compared to converting ice into water. Just a few inches of fresh snow can produce several liters of potable water when melted.
As long as the snow looks clean, ingesting newly fallen snow is generally safe with minimal risk from pollutants or microbes, especially at higher elevations. Boiling snow before drinking eliminates any potential bacteria or viruses that may be present.
In polar regions, cultures like the Inuit rely on snow as their primary water source. When no other water sources are available, clean snow provides crucial hydration.
Is it safe for everyone to eat snow?
While snow is generally safe for most people, some groups are more at risk from potential contaminants. Here are a few considerations regarding who should refrain from eating snow:
Infants and young children
It’s not recommended infants under 1 year eat snow. Their immune systems are not yet fully developed, putting them at higher risk of getting sick from any bacteria present. Children under 5 years old are also more susceptible to contaminants. It’s best to keep young kids from putting snow in their mouths when possible.
Pregnant women
Pregnant women should take extra precautions and avoid eating snow whenever feasible. Even if pollution levels are low, ingesting contaminants could potentially impact the developing fetus. Norovirus from snowfall may also pose health risks during pregnancy.
Those with compromised immunity
People with weakened immune systems due to chronic illness, cancer treatment, organ transplant, HIV/AIDS, and autoimmune disorders need to be more careful consuming snow. Their bodies are less equipped to fight off pathogens or environmental toxins. Consuming snow is not recommended for the immunocompromised.
Individuals with chronic illness
Those with chronic conditions like kidney disease, diabetes, chronic respiratory illness, or hypertension should avoid eating snow whenever possible. Environmental toxins, nitrates, bacteria, and cold temperature pose unique risks that can worsen symptoms. Checking with a doctor first is advised if at risk from pre-existing medical conditions.
The elderly
Senior citizens and the elderly are at increased risk for foodborne illness. Older adults should take precautions and avoid eating snow, especially if snow originated in urban areas prone to pollution. Sticking to bottled water or boiled snow is best.
Dangers of eating snow
While fresh snow is generally safe in moderation, there are some risks to ingesting significant amounts:
Hypothermia
Eating snow lowers body temperature as it melts, essentially the same effect as drinking an icy beverage. Consuming large volumes can potentially lead to hypothermia if heat loss occurs faster than the body can replenish it.
Frostbite on lips or mouth
The icy temperature of snow can damage skin cells, causing frostnip or frostbite in the mouth and lips. This risk is highest eating snow during cold weather or eating large chunks rather than letting it melt.
Choking hazard
Eating snow, especially shoveling it directly into the mouth, poses a choking risk like any solid food. Taking small portions melted in the mouth can reduce this risk.
Toxins and pollutants
While amounts are typically low, snow may contain irritants, particulate matter, pesticides, carcinogens, and other hazardous substances absorbed from air pollution. Long term ingestion of contaminated snow could potentially cause health issues.
Bacterial and viral infection
Snow may contain norovirus, E. coli, salmonella, campylobacter, giardia and other pathogens from animal droppings. These can cause illness if consumed, especially for those with compromised immunity.
Hypertension from excess nitrates
While nitrate levels are very low, eating large amounts of snow could potentially cause a buildup of nitrates. In certain individuals, this may contribute to high blood pressure. Those with kidney disease may be especially at risk.
Electrolyte imbalance
Similar to drinking only water, consuming lots of snow may flush electrolytes from the body. In extreme cases, this electrolyte loss can result in depleted blood sodium levels.
Safe snow eating guidelines
To enjoy snow while minimizing risk, follow these best practices:
– Let snow melt in mouth instead of chewing chunks to avoid frostbite.
– Consume freshly fallen snow before it touches the ground.
– Avoid snow near roads or in urban areas.
– Do not eat discolored, dirty snow.
– Consume only small portions at a time.
– Avoid excessive intake that may lower body temperature.
– Boiling snow before ingesting kills potential bacteria and viruses.
– Pay attention to signs of hypothermia like shivering and confusion.
– Keep infants, pregnant women, and the immunocompromised from eating snow.
Alternative snow activities
Instead of ingesting snow, enjoy it in safer ways by:
- Having snowball fights
- Building snowmen and snow forts
- Sledding
- Making snow angels
- Shoveling or plowing snow
- Playing winter sports outside
Conclusion
Freshly fallen snow is generally safe to eat in small amounts. It offers hydration in winter survival situations with minimal risk from pollutants and microbes. However, certain groups should avoid consumption due to higher risk of illness. Excessive intake may also lower body temperature. While pure-looking, snow may contain traces of toxins, bacteria, and nitrates that can build up over time. Following basic safety guidelines allows enjoying snow through winter activities rather than ingesting large quantities. When in doubt, stick to bottled water or boiled snow to reduce any potential hazards. With proper precautions, everyone can safely play in winter wonderlands without needing to actually eat the snow.