Protect yourself from the health effects of wildfire smoke

Think of summer and you probably think of time spent outdoors: blue skies, beach days, ballparks. But summer also is wildfire season, when drifting smoke can cause health issues hundreds of miles beyond the blazing forest.

Researchers have found that wildfire seasons are getting longer, fires are becoming more frequent, and the number of acres burned each year is increasing. So it’s important to understand the potential health effects of wildfire smoke and how you can protect yourself and your loved ones.

What are the health effects of wildfire smoke?

For generally healthy people, breathing in wildfire smoke can cause:

• Coughing or wheezing
• Difficulty breathing
• Stinging eyes
• Scratchy throat
• Runny nose
• Irritated sinuses
• Headaches
• Chest pain
• Fast heartbeat

Older adults, infants and children, and people who are pregnant are especially likely to have these kinds of symptoms from breathing in wildfire smoke.

For people with asthma, chronic obstructive pulmonary disease (COPD) or other chronic lung conditions, wildfire smoke can cause more serious problems. These can include asthma attacks or flare-ups or worsening of COPD symptoms.

“For most healthy people, it’s more of a nuisance to have a sore throat, watery eyes, a runny or stuffy nose, or to become hoarse because of the irritation,” says Richard A. Oeckler, M.D., Ph.D., a critical care specialist and pulmonologist at Mayo Clinic in Minnesota and a former fire department captain in the New York City metro area. “But for people with asthma or COPD — people who have reactive airways — it may not take much to set off a serious episode of bronchospasm, and their response can be quite severe.” Bronchospasm is a narrowing of the airways that can cause wheezing and shortness of breath.

Those with heart disease also can be at increased risk. “Studies show that the incidence of heart attacks and heart failure can increase during smoke events,” says Dr. Oeckler. “Most people may not associate the heart with air quality per se, but the heart and lungs are intricately related. If you’re having difficulty breathing, that puts strain on the heart.”

Health effects of wildfire smoke range over time — and distance

If your exposure to smoke is prolonged or repeated, it could lead to chronic respiratory disease. It’s something Dr. Oeckler saw firsthand as he provided coverage with the Fire Department of New York after the 9/11 attacks. “We had several young, physically fit members in our squad who were playing competitive hockey, football and baseball, who were exposed to heavy smoke, dust and chemical inhalations in the weeks following 9/11. Soon, they had a hard time walking up stairs, walking down the block. Their hearts and lungs aged rapidly,” he says.

Distance from fires also is a factor, but being far away doesn’t equal safety. Wildfire smoke has harmful gases, such as carbon monoxide, as well as particles. While the gases don’t tend to travel far, the particles do. The smallest particles — those up to 2.5 microns in diameter, referred to as PM2.5 — travel farthest and cause the most concern.

“Most of the larger particles either drop out with distance or can get filtered out either in your nose or respiratory tract,” says Dr. Oeckler. “But particles that are 2.5 and below get all the way down to the air sacs in your lungs, called alveoli, where the oxygen and carbon dioxide exchange takes place. It is this area we worry about for not only acute concerns but also long-term effects.”

Those tiny particles also are invisible, which means you can be inhaling particles from faraway wildfires even when you can’t see or smell smoke.

How to protect yourself from wildfire smoke’s health effects

If wildfires are burning near you, follow the guidance of your local emergency management officials.

If you’re outside the immediate fire area, monitor the air quality index (AQI) near you using a weather app or by visiting AirNow, which reports air quality data. The AQI is a color-and-number rating. The range goes from green (0 to 50) for “Good” to maroon (301 to 500) for “Hazardous.” You also can see a map of smoke plumes from distant wildfires using the Fire and Smoke Map at AirNow.

If the AQI in your area is above 100 — or above 50, if you are at higher risk — consider taking these precautions:

Protecting from wildfire smoke if you are outdoors

• Limit time outdoors. When you’re outside, avoid strenuous activities that make you breathe harder.
• If you’re at higher risk, stay indoors if possible. If you must go outside, wear a respirator such as an N95 mask that can filter out tiny PM2.5 particles. Cloth and surgical masks can’t do this. See this fact sheet on choosing a respirator and wearing it correctly.

 Protecting from wildfire smoke when you are indoors

• Keep doors and windows closed as much as possible. If you need to open windows to cool your home, consider wearing a respirator indoors.
• Use filters in your home’s heating and air conditioning system that have a MERV (minimum efficiency reporting value) rating of 13 or higher if your system can use them.
• Consider getting an air purifier. The best air purifiers for wildfire smoke are ones with HEPA (high efficiency particulate air) filters. HEPA filters remove 99.97% of airborne particles in the 0.3-micron size range as well as dust, pollen, mold and bacteria. You also can build a DIY air cleaner using a box fan and MERV 13 filters.

Finally, Dr. Oeckler stresses the importance of taking the risks seriously, even if you can’t see any wildfire smoke. “It doesn’t have to be to the point where it grays the sky,” he says. “If the air quality index is 50, 60 or higher — and certainly if it’s above 100 — please take it to heart, because it’s something that can potentially cause you serious harm.”