Every year, thousands of homes are destroyed by wildfires. When you think about wildfires, your imagination might conjure images of fleeing your home just ahead of rushing flames. However, the flames are not the leading cause of deaths associated with wildfires. Smoke inhalation poses the greatest threat to those in areas affected by these out-of-control blazes.

As much as 80 percent of fire deaths are caused by smoke inhalation. Many people who suffer from smoke inhalation won’t show symptoms until 24 to 48 hours after exposure.

Why Wildfire Smoke is Dangerous

Inhaling smoke causes damage by depriving the body of necessary oxygen. It can also cause chemical irritation as the body is exposed to the thousands of chemical components of wildfire smoke. These compounds include harmful particles and gases that may pose a severe threat to people and animals located nearby or downwind of the fire.

The exact components of wildfire smoke depend on many contributing factors, including the variety of burning vegetation, the moisture content, burn temperature, wind conditions, and certain weather-related conditions.

Wildfire smoke may include any or all of the following:

• Water vapor
• Particulate matter
• Trace minerals
• Carbon monoxide
• Carbon dioxide
• Nitrogen oxide
• Volatile organic compounds (VOCs)
• Acrolein
• Formaldehyde

The biggest threat to those downwind of a wildfire is particulate matter. Smoke from a wildfire contains fine and ultrafine particles of whatever material is burning. These often almost microscopic particles are most dangerous because they penetrate deeply into your lungs. Ultrafine particles, those measuring smaller than 0.01 microns, are small enough to enter the bloodstream. One these particles enter the bloodstream, they can travel through the body and affect internal organ function.

Smoke Behavior

It is difficult to predict how wildfire smoke will behave. Factors like weather patterns, terrain, fire temperature all contribute to wildfire behavior.

Wind may have the greatest effect. Windy conditions can result in lower smoke concentrations. However, high winds cause a fire to spread rapidly, which results in a larger burn area and a greater impact.

Regional weather systems can also influence how wildfire smoke will spread. An intense regional weather system can push a fire for days, making it a dominant factor in determining how and if smoke will affect any given area.

Determining Who is at Risk

Most healthy adults will recover from minor amounts of smoke inhalation without suffering any long-term health problems. Certain segments of the population, however, are at a higher risk of experiencing serious health consequences.

At-risk groups include:

• Small children. Because of their relatively small body weight, toxins may have a greater impact on young children. Also, because their lungs are still developing, they are more vulnerable to smoke exposure.
• Pregnant women. Exposure to wildfire smoke puts not only the pregnant mother but also her unborn child at risk of developing major health issues.
• The elderly. Because many older adults have pre-existing lung or heart conditions, smoke inhalation is considered more dangerous for members of this group.
• Those suffering from respiratory disease. Conditions including COPD, emphysema, chronic bronchitis, asthma, or any other respiratory diseases can cause serious issues for those exposed to wildfire smoke.
• Those suffering from cardiovascular disease. Conditions such as high blood pressure, heart failure, and cerebrovascular disease raises the risk of heart attack, stroke, and sudden death from cardiac arrhythmia when combined with inhalation of wildfire smoke.

Preparation and Safety Tips

You can find smoke impact forecasts for your area by visiting this website: http://cwfis.cfs.nrcan.gc.ca/interactive-map.

What to do when your area is at risk:

Limit time outdoors. When possible, stay inside buildings that are effectively insulated from outdoor air.

If you must go outside, wear a mask. A respirator mask with an N95 or N100 rating will protect you from exposure to tiny smoke particles.

Create an oasis of clean air inside your home. Keep windows and doors closed. Seal all outside openings including vents. If you must use an air conditioner, close off the fresh air intake and adjust the setting to recirculate. A high-performance air purifier like the Austin Air HealthMate + Plus HM450 is an effective tool for removing smoke particles that make it into your home.  Using an air purifier is a critical step if you live downwind of a wildfire, even if you are located some distance away from the smoke source.

Take measures to avoid further polluting your indoor air. Refrain from burning candles, heating with a fireplace or woodstove, or even vacuuming ((unless your vacuum cleaner is equipped with a true HEPA filter). Since these activities can increase levels of indoor air pollution.

Wildfires are expected to continue and even increase in intensity in the coming years. While smoke from wildfires can have a negative impact on your health, there are measures you can take to protect you and your family.