Wildfires and Indoor Air Quality: What You Need to Know

An indoor air quality monitor will tell you the level of particles you have in your house — though be skeptical of those that claim to detect everything — but you can also just use your nose, suggests Farmer.

“If there’s a smoke event or you live near a busy road, you can generally smell or see that the air quality isn’t good,” she says.

Inexpensive fixes can make a big difference, says Jamie Gold, a wellness design consultant in San Diego and author of Wellness by Design. Normally you might start by opening a window (unless your area is experiencing smoke from wildfires) — a strategy recommended by the EPA to improve air circulation.

“It’s ideal to have the best-ventilated space and as much fresh air as you can get,” Gold says.

Make use of properly installed bathroom or kitchen fans too. Without proper venting from the kitchen to the outside, your home can be filled with grease, food odors and smoke, she adds.

“If you’re not using bathroom ventilation, you can have mold and mildew buildup,” Gold says. “Use fans if they’re working well and replace them if they’re not.”

Focus on air filters and purifiers

Use efficient air filters for your home’s HVAC system and change them every six to 12 months to improve indoor air quality. Look for HEPA filters but avoid ones that use UV light, which can generate ozone, a serious air pollutant, cautions Farmer. Ditto for filters with ionizers or hydroxyl radical generators.

“They don’t do anything that the plain HEPA filter doesn’t, plus they have the potential to introduce toxic molecules into your indoor environment,” she explains.

​Portable air purifiers can filter out pollutants in a room and, along with best practices recommended by the U.S. Centers for Disease Control and Prevention, can be part of an overall plan to guard against germs, bacteria and the COVID-19 virus, according to the EPA. Purifiers pull air through a HEPA filter, explains Farmer, and even the most affordable models effectively clear out aerosols.

Air purifiers have helped Kathy Przywara, who has asthma, improve her home’s air quality.

Courtesy of Kathy Przywara

Kathy Przywara, 58, takes medication daily for asthma, and living in Mountain View, California – a wildfire zone – is challenging. She runs her air purifiers frequently.

“When there are active fires and smoke is blown into the valley, I have more asthma symptoms,” says Przywara, vice president of community for the Asthma and Allergy Foundation of America.

“You can also just buy a box fan and duct-tape a filter onto it, which works really well,” adds Farmer.

If you live in an area where the outdoor air is quite contaminated — say, by wildfire smoke — upgrade the filter in your HVAC system, says Farmer. Get a filter with as high a MERV value as your HVAC system will handle.

Prevent mold and mildew

Lowering the relative humidity in your house is essential to preventing the growth of mold, bacteria and viruses, says Doug Hoffman, 74, executive director of the National Organization of Remediators and Mold Inspectors (NORMI), a nonprofit in Abita Springs, Louisiana. NORMI educates the public and trains professionals to identify and remove toxic mold.

“Typically, mold, bacteria and viruses thrive in environments where the relative humidity is higher than 60 percent or lower than 40 percent, so stay within that range,” says Hoffman, who suggests using ventilation fans, vacuuming regularly and making sure you have fresh air coming into the house.

For an in-depth look at the humidity environment in your home, a professional may do swab or aerosol testing, particulate counts, and relative humidity and temperature measurements to create an indoor air quality (IAQ) profile.

This can be used to personalize a home solution if problems are found, explains Hoffman. For a 1,500- to 1,700-square-foot home or condo, expect to pay $600 to $1,200 for a comprehensive analysis.

To fix mold issues, experts usually sanitize to lower the microbial count. That may involve fogging the space and wiping it down, or using air purification technology. In severe cases, remediation — removing affected materials — might be required.

Get relief from radon

Radon poses another risk to indoor air quality. This naturally occurring radioactive gas is found in most soil types, and can move up through the ground into your home through the foundation. When present in large amounts, it’s the second-leading cause of lung cancer, notes Gold.

“It’s invisible, odorless and present in many homes at the lower level,” she says. “You may have more people in your home right now — college kids back from school or an elderly relative — or you’re using your basement as a work-from-home space.”

Radon detectors are inexpensive and can be purchased online or at your local hardware store. Professional radon services, which are often more accurate, can also evaluate whether there’s radon in your home.

David and Daniela Naidu used a radon test and found levels in their apartment were high.

Courtesy of the Naidu Family

In Boulder, Colorado, David Naidu, 57, and his wife, Daniela, 54, took advantage of the city’s free radon test kit, and took readings over several days.

“We discovered the radon level in our apartment was high, so our landlord agreed to hire a radon mitigation company,” says Naidu.

To reduce the level of radon, the company increased the ventilation of gas below Naidu’s concrete floor, blowing it out of the apartment through a hole drilled into the wall. The couple are relieved the issue has been resolved, especially since they are also in a wildfire zone.

Editor's note: This story was originally published on November 10, 2020. It has been updated to reflect new information.