group of people roasting marshmellows by campfire

Should We Worry about Woodsmoke at Home?

October 23, 2023
Dr. Darby Jack

Darby Jack, PhD, Professor of Environmental Health Sciences at CUIMC

As more people grow concerned about the health effects of wildfire season and woodsmoke, it’s easy to wonder: Should we also worry about woodsmoke from our own fireplaces and backyard firepits?

For most people, there’s little to fret about when it comes to at-home woodsmoke, but there are circumstances that can create real health concerns, particularly for those with asthma, chronic obstructive pulmonary disease (COPD), or other underlying conditions.

“A scented candle in the bathroom when guests come over won’t kill anyone,” says Darby Jack, PhD , professor of environmental health sciences at the Mailman School of Public Health. “But daily indoor combustion may be a risk, especially if you’re already vulnerable.”

How to Stay Healthy Around Woodsmoke at Home

Moderation is the number one way to reduce the health risks of everyday forms of combustion, such as fireplaces (inside and outdoor), incense, and scented candles.

“There’s strong evidence that long-time exposure to air pollution is a major risk for all sorts of issues,” says Dr. Jack, who studies the health effects of everyday cooking over woodsmoke in other countries. “But the scientific literature on the impact of shorter time periods is less conclusive.”

So, is it safe to break out the s’mores and strike up the firepit on weekends?

“In general, air pollution is harmful and should be avoided. But if you’re sitting around a firepit for a few evenings over the fall, you’re probably okay.”

However, you should be a little more cautious indoors.

Dr. Jack explains that tiny particles stay airborne for hours, even after a fire or candle flame is out. “Any combustion inside the house should be limited, especially scented candles,” he says. “And don’t use an open fireplace for more than occasional, aesthetic reasons; a few times a year is probably alright.” However, if you’re heating your home every day with an open fireplace, there can be cause for concern.

Simple Tips for Cleaner Air

For all these sources of smoke, Dr. Jack suggests a few helpful habits for improving air quality.

  • Use dry wood: Damp wood gives off more smoke, which can worsen health problems. “The moisture content of fuel will change its combustion efficiency. Well-seasoned firewood will smoke less,” Dr. Jack explains.
  • Keep your distance: When gathering around backyard firepits, sit away from the smoke. “Being outdoors is not a get-out-of-jail-free card; there’s always someone in the plume,” says Dr. Jack. But staying away from the smoke can reduce your exposure.
  • Maintain your indoor fireplace: Make sure your flue (chimney) is clean, and that your system is set up for good combustion. “If you have a closed fireplace with a good firebox and air control, most of your smoke will vent outdoors,” Dr. Jack says. Open fireplaces are likely to be more polluting.
  • Get a low-cost air monitor: If you burn wood indoors regularly for heating, an air monitor is a good way to understand changes in your air quality that result from combustion inside. You don’t need a research-grade device; choose an inexpensive monitor that measures PM 2.5 (fine particles that have been linked to asthma, heart disease, and low birth weight).
  • Ventilate, if you can: While it may not be possible in cold weather, opening a window can help reduce particulates and clear the air.
  • If you have a health condition, be extra careful: For those with asthma, COPD, or who are pregnant, it’s important to take more precautions. There’s good evidence that air pollution during pregnancy, for example, can have effects, especially within certain “biological windows of susceptibility.” If a pregnant woman is exposed to air pollution during these windows, Dr. Jack worries that fetal development could be impacted.
  • Switch fireplaces: Saving the expensive tip for last, if you’ve been enjoying an open fireplace, consider investing in one with a door and sealed combustion chamber.



Darby Jack, PhD is a Professor of Environmental Health Sciences at CUIMC. He studies environmental health risks in developing countries, the health impacts of climate change, and the role of the urban environment in shaping health.