What’s in smoke from a wildfire?

Smoke is made up of small particles, gases and water vapor. Water vapor makes up the majority of smoke. The remainder includes carbon monoxide, carbon dioxide, nitrogen oxide, irritant volatile organic compounds, air toxics and very small particles.

Is smoke bad for me?

Yes. It’s a good idea to avoid breathing smoke if you can help it. If you are healthy, you usually are not at a major risk from smoke. But there are people who are at risk, including people with heart or lung diseases, such as congestive heart disease, chronic obstructive pulmonary disease, emphysema or asthma. Children and the elderly also are more susceptible.

What can I do to protect myself?

• Many areas report EPA’s Air Quality Index for particulate matter, or PM. PM (tiny particles) is one of the biggest dangers from smoke. As smoke gets worse, that index changes -- and so do guidelines for protecting yourself. So listen to your local air quality reports.
• Use common sense. If it looks smoky outside, that’s probably not a good time to go for a run. And it’s probably a good time for your children to remain indoors.
• If you’re advised to stay indoors, keep your windows and doors closed. Run your air conditioner, if you have one. Keep the fresh air intake closed and the filter clean. 
• Help keep particle levels inside lower by avoiding using anything that burns, such as wood stoves and gas stoves – even candles. And don’t smoke. That puts even more pollution in your lungs – and those of the people around you.
• If you have asthma, be vigilant about taking your medicines, as prescribed by your doctor. If you’re supposed to measure your peak flows, make sure you do so. Call your doctor if your symptoms worsen.

How can I tell when smoke levels are dangerous? I don’t live near a monitor.

Generally, the worse the visibility, the worse the smoke. One can use visibility to help gauge wildfire smoke levels and approximate air quality.

How do I know if I’m being affected?

You may have a scratchy throat, cough, irritated sinuses,
headaches, runny nose and stinging eyes. Children and people with lung diseases may find it difficult to breathe as deeply or vigorously as usual, and they may cough or feel short of breath. People with diseases such as asthma or chronic bronchitis may find their symptoms worsening. 

Should I leave my home because of smoke?

The tiny particles in smoke do get inside your home. If smoke levels are high for a prolonged period of time, these particles can build up indoors. If you have symptoms indoors (coughing, burning eyes, runny nose, etc.), talk with your doctor or call your county health department. This is particularly important for people with heart or respiratory diseases, the elderly and children.

Are the effects of smoke permanent?

Healthy adults generally find that their symptoms (runny noses, coughing, etc.) disappear after the smoke is gone.

Do air filters help?

They do. Indoor air filtration devices with HEPA filters can
reduce the levels of particles indoors. Make sure to change your HEPA filter regularly. Don’t use an air cleaner that works by generating ozone. That puts more pollution in your home.

Do dust masks help?

Paper “comfort” or “nuisance” masks are designed to trap large dust particles -- not the tiny particles found in smoke. These masks generally will not protect your lungs from wildfire smoke.

How long is the smoke going to last?

That depends on a number of factors, including the number of fires in the area, fire behavior, weather and topography. Smoke also can travel long distances, so fires in other areas can affect smoke levels in your area. I’m concerned about what the smoke is doing to my animals. 

What can I do?

The same particles that cause problems for people may cause some problems for animals. Don’t force your animals to run or work in smoky conditions. Contact your veterinarian or county extension office for more information.

How does smoke harm my health?

One of the biggest dangers of smoke comes from particulate matter -- solid particles and liquid droplets found in air. In smoke, these particles often are very tiny, smaller than 2.5 micrometers in diameter. 

How small is that?

Think of this: the diameter of the average human hair is about 30 times bigger. These particles can build up in your respiratory system, causing a number of health problems, including burning eyes, runny noses and illnesses such as bronchitis. The particles also can aggravate heart and lung diseases, such as congestive heart failure, chronic obstructive pulmonary disease, emphysema and asthma.

What about firefighters?

Firefighters do experience short-term effects of smoke, such as stinging, watery eyes, coughing and runny noses. Firefighters must be in good physical condition, which helps to offset adverse effects of smoke. In addition to being affected by particles, firefighters can be affected by carbon monoxide from smoke. A recent Forest Service study showed a very small percentage of firefighters working on wildfires were exposed to levels higher than occupational safety limits for carbon monoxide and irritants.

Why can’t the firefighters do something about the smoke?

Firefighters first priorities in fighting a fire are, by necessity, protecting lives, protecting homes and containing the wildfire. Sometimes the conditions that are good for keeping the air clear of smoke can be bad for containing fires. A windy day helps smoke disperse, but it can help a fire spread. Firefighters do try to manage smoke when possible. As they develop their strategies for fighting a fire, firefighters consider fire behavior and weather forecasts, topography and proximity to communities – all factors than can affect smoke.

Why doesn’t it seem to be as smoky when firefighters are working on prescribed fires?

Land managers are able to plan for prescribed fires. They get to choose the areas they want to burn, the size of those areas and the weather and wind conditions that must exist before they begin burning. This allows them to control the fire more easily and limit its size. Those choices don’t exist with wildfires. In addition, wildfires that start in areas that haven’t been managed with prescribed fire often have more fuel, because vegetation in the forest understory has built up, and dead vegetation has not been removed.