More than 27 million homes in the U.S. have fireplaces, and most of them burn wood. Add to that another 9.3 million homes with wood-burning stoves.* That’s bad news for indoor air quality even if you don’t actually own a fireplace or wood stove but only live near one. Up to 70% of the smoke from chimneys re-enters other homes nearby, according to the Contra Costa (Calif.) Health Services Department. And though the smell of wood burning may seem cozy and romantic, breathing wood smoke is actually as harmful as breathing tobacco smoke.

Like tobacco smoke, wood smoke contains fine and ultrafine particles as well as carbon monoxide, formaldehyde and sulfur dioxide. Wood smoke also contains nitrogen oxides that can cause scarring in lung tissue, and contains carcinogenic chemicals such as benzene and dioxin.

Modern, efficient homes are also susceptible

Studies have shown that homes with wood-burning fireplaces and stoves have elevated levels of indoor air pollutants regardless of whether the system is drafty or airtight. Fine particle levels (PM 2.5) in wood-heated homes are, on average, 26% higher than homes without wood-burning heat, according to air quality officials in the State of Washington. Smoke that goes up and out the chimney recirculates back into the home and also enters neighbors’ homes, even when their homes are energy efficient and weather tight. The fine and ultrafine particles in wood smoke are so small that tightly sealed windows and doors do not stop them from entering.

Even at very low levels, wood smoke is unhealthy, according to the Minnesota Pollution Control Agency. And even short exposures to wood smoke can cause serious health effects. Among healthy people, wood smoke causes coughing, headaches, eye and respiratory irritations. Among children, breathing wood smoke can cause asthma attacks. Among older populations, it can cause heart attacks. A study by the California Air Resources Board linked wood smoke to a 10% increase in hospital admissions for respiratory problems.

Steps you can take to control wood smoke

Fortunately, there are steps you can take to help you protect yourself and your family against wood smoke. By taking action, you can help protect your own household and others from this dangerous indoor air quality hazard.

1. Avoid burning wood in your home.

2. If you must burn wood at home, keep in mind that the hotter the fire the less smoke produced. Also, avoid burning wood that is moist.

3. If you can see smoke coming from the chimney, adjust your fireplace or stove to allow more air into the burning chambers or burn wood with less moisture.

4. If wood smoke is a problem in your neighborhood, limit strenuous activities outside when the air is smoky.

5. If you have a fireplace or wood-burning stove, or have neighbors that do, clean the air in your home with an air purifier such as the IQAir GC MultiGas. The GC MultiGas is the #1 Rated room air purifier for controlling smoke, and features HyperHEPA filtration of fine and ultrafine particles as well as exceptional effectiveness against gases, chemicals and odors.

To learn more, visit the EPA BurnWise website.

* Estimates of homes with wood burning fireplaces and stoves are from “The Proceedings of a U.S. EPA and Air Waste Management Association Conference: Emission Inventory: Living in a Global Environment,” 1998. Actual numbers today would be even higher.