Why shouldn't you eat snow?

Eating snow may seem like a fun idea, especially for kids, but there are some important reasons why you should avoid ingesting snow whenever possible. Snow can contain hidden contaminants and substances that could make you sick. Additionally, the act of eating snow itself can be dangerous due to the rapid cooling effect it has on your body. In this article, we’ll explore the main reasons why you should refrain from eating snow.

Table of Contents

What are the potential contaminants in snow?

Snow acts as a sponge, absorbing whatever it comes into contact with as it falls from the sky and settles on the ground. This means that snow can contain:

Bacteria and viruses from animal waste, such as E. coli, salmonella, and giardia
Chemicals from car exhaust fumes and industrial pollution

Dirt and debris from roads and sidewalks
Pesticides and fertilizers from lawns and farms

These contaminants get incorporated into the snowflake structure as snow forms in the clouds and as it falls to the earth. Eating snow means you’ll also be ingesting all of these hidden nasties.

Why is snow more likely to contain contaminants than rain?

Snow has a larger surface area than raindrops due to its intricate crystalline structure. This allows snowflakes to collect and concentrate more pollutants from the air as they drift downwards. Snow also hangs around longer on the ground, allowing more time for contamination from the earth to become incorporated into the layers of snow.

Raindrops fall straight down, minimizing contact with contaminants. Rain also washes pollutants from the air and the ground, rather than absorbing them. This makes snow more prone to contamination issues than rainwater.

What harmful bacteria could be lurking in snow?

Several types of dangerous bacteria have been detected in snow samples in research studies. These include:

E. coli – Can cause gastrointestinal illness, urinary tract infections, pneumonia and other conditions.
Listeria – Causes the serious infection listeriosis, with symptoms like fever, muscle aches, nausea and diarrhea.
Salmonella – Leads to salmonellosis food poisoning, with abdominal cramps, vomiting and fever.

Enterococcus – An opportunistic pathogen that can cause difficult-to-treat infections.

The presence of fecal coliforms like E. coli and Enterococcus species in snow indicates contamination by fecal matter from warm-blooded animals. Viruses like norovirus, hepatitis A, adenoviruses and rotavirus can also be present in snow contaminated by feces.

What are some non-biological contaminants that could be in snow?

In addition to bacteria and viruses, snow can contain chemical pollutants that can pose a health hazard if consumed. These include:

Vehicle exhaust emissions – Contains carbon monoxide, nitrogen oxides, benzene and other solvents.
Pesticides – Can be toxic to the nervous system and disrupt hormone function.
Herbicides – Certain types are carcinogenic.

Fertilizers – May contain nitrogen compounds that can affect oxygen transport.
Industrial emissions – Can include heavy metals like lead, arsenic and mercury that accumulate in body tissues.

The concentration of these contaminants in snow depends on the degree of pollution in the area. Higher levels are usually detected in urban and industrial areas.

What physical dangers are posed by ingesting snow?

Beyond toxic contaminants, the physical properties of snow itself can make it hazardous if consumed in large quantities:

Cold temperature – Eating snow lowers the temperature inside your mouth and body as it melts. This can cause perflex, an unusual cooling of the body core that can lead to shivering, slurred speech and difficulty moving or thinking clearly.
Volume – A large intake of snow fills up the stomach with water. This can dilute the concentrations of blood plasma sodium and chloride, leading to a rare but dangerous condition called water intoxication, with symptoms like headache, nausea, fatigue, seizures and coma.

Sharp edges – Jagged, partially melted snow crystals can cut and scrape the delicate tissues of your mouth, esophagus and stomach.

These physical dangers are mainly a concern if a large amount of snow is consumed at once, especially on an empty stomach. Moderation is key if you do opt to eat snow.

Health risks from contaminated snow

Fresh fallen snow may look pristine and pure, but it can actually harbor a surprising array of disease-causing organisms and toxic pollutants that can make you sick if the snow is ingested.

What illnesses can you get from contaminated snow?

Eating snow contaminated with pathogenic microbes can lead to:

Gastroenteritis – Diarrhea and vomiting caused by bacteria like E. coli, salmonella and giardia or viruses like norovirus and rotavirus.
Food poisoning – Abdominal cramps, nausea and fever from bacteria like listeria, staphylococcus or Clostridium perfringens.

Respiratory infections – Sore throat, runny nose and cough caused by viruses and bacteria like adenovirus, influenza, streptococcus, pseudomonas.
Brain infections – Swelling of the brain from parasites like Toxoplasma gondii.
Worms – Intestinal worms that can cause malnutrition, anemia and wasting.

Ear infections – Bacteria like Pseudomonas aeruginosa can cause swimmer’s ear.
Eye infections – Microbes like E. coli and Pseudomonas can cause conjunctivitis or pink eye.

The symptoms of these illnesses generally start 1-3 days after ingesting contaminated snow and commonly include nausea, vomiting, diarrhea, fever, headaches and body aches. The symptoms are usually temporary, lasting a few days to a week, but can be life-threatening in vulnerable individuals.

What health effects are caused by chemicals in snow?

Ingesting snow contaminated by toxic pollutants can have these effects:

Nausea, diarrhea and vomiting – From solvents, pesticides, herbicides and fertilizers.
Neurological symptoms – Weakness, dizziness, numbness, headaches and cognitive issues from heavy metals like lead and mercury.

Kidney damage – From ethylene glycol antifreeze leaking from vehicles.
Cancer – Carcinogenic compounds from vehicle exhaust and industrial emissions raise cancer risk over the long term.
Hormonal effects – Endocrine disruptors like phthalates and bisphenol A mimic or alter hormone pathways.

Oxygen deprivation – Methemoglobinemia, with shortness of breath and blue-tinged skin, from nitrates and nitrites.

Younger children are at higher risk of adverse effects from contaminants in snow due to their developing organs, lower body weight and higher intake relative to size.

Which groups are most vulnerable to getting sick from eating snow?

The following groups have a higher likelihood of getting ill from ingesting snow:

Young children – They are more likely to put snow in their mouths and have naive immune systems.
Elderly – Increased risk of infections due to weaker immunity.
Pregnant women – Vulnerable to listeria, toxoplasmosis and other infections that also threaten the fetus.

Immunocompromised – Individuals with chronic diseases like HIV/AIDS, diabetes and cancer.
People with liver or kidney disease – Impaired ability to detoxify contaminants.

However, previously healthy individuals can also experience snow-related illnesses if enough pathogens or toxins are ingested. People of all ages and health statuses should avoid eating snow whenever possible.

Safety tips for handling and consuming snow

If you want to consume snow, there are some basic safety practices to follow that can help reduce (though not eliminate) the risk of illness:

Avoid eating snow in areas with higher contamination risk

Steer clear of ingesting snow:

Near roads due to car exhaust particulate, leaked fluids and road salt.

In city parks and industrial zones which have higher air pollution.
Near garbage cans or areas where animals congregate and defecate.
That has thawed and refrozen multiple times, concentrating contaminants each time.

With any discoloration, odor or debris mixed in.

Opt for the cleanest, freshest snow you can find, away from potential sources of pollution.

Consume small amounts infrequently

Limit your snow ingestion to:

Small handfuls or snowballs.
Once per season at most, not daily.
On a full stomach, not when hungry or thirsty.

This minimizes risk from the snow’s cooling effects and volume-related issues. Don’t make it a frequent habit or eatbowlfuls at once.

Avoid giving snow to vulnerable groups

Do not deliberately feed snow to:

Children under 5 years old.

Elderly individuals.
Pregnant women.
Anyone who is immunocompromised or chronically ill.

They are at higher risk for adverse effects from any pathogens or toxins present. Help keep them safe.

Wash hands before and after touching snow

Practice good hygiene:

Wash hands with warm water and soap for at least 20 seconds before handling or eating snow.

Wash hands again after snow play.
Avoid touching your eyes, nose or mouth while playing with snow.

This prevents accidentally ingesting contaminants and protects you from direct transmission of viruses and bacteria through your mucous membranes.

Sterilize snow before consumption

You can reduce your risk by:

Boiling – Bring snow to a rolling boil for 1 minute to kill most microbes.
Melting – Let snow melt slowly at room temperature instead of in your mouth.

Water filtration – Use a filter rated to remove bacteria and viruses.

However, this won’t remove chemical pollutants already dissolved in the snow. Avoid eating any discolored snow.

Conclusion

Eating snow is generally inadvisable, especially in urban areas and for vulnerable groups like children and the elderly. Snow can harbor a wide range of contaminants that can make you sick, including bacteria that cause serious gastrointestinal, respiratory and neurological illness. Toxic chemicals from pollution are also a concern. If you do choose to eat snow, stick to small amounts of the cleanest snow you can find and take safety precautions like washing hands and sterilizing snow before ingesting. However, the only way to eliminate risk completely is to avoid consumption of snow altogether.