Clean Air

Even though people can spend a lot of time outdoors, most, including children, spend most of their time indoors. Therefore, it is important to consider inhalation hazards that may be present in both environments (indoor and outdoor). Certainly, indoor hazards become increasingly present in older buildings/infrastructure, but they may also be present in newer buildings as well. Outdoor air quality is largely seasonal, but can also impact indoor air quality at various times of the year. Here is a brief list of indoor inhalation hazards to consider (hazards are not limited to this list):

Carbon monoxide

  • As a by-product of household utilities (e.g., water heater, stove, etc.) or from highways or industrial sources. If there are risks of exposure to Carbon Monoxide, we strongly suggest the usage of carbon monoxide detectors/alarms. Each year, over 400 people die in the US from accidental carbon monoxide exposures. Reduce your chances of experiencing such a tragedy by ensuring you are equipped to detect and respond to increased carbon monoxide levels.


  • Radon is a naturally occurring gas from the ground that can cause lung cancer and poses a greater risk to children than adults, whose breathing rates are higher. In Montana, just over 47% of homes tested have radon levels above 4 picoCuries per liter of air (pCi/L), which is the Environmental Protection Agency’s (EPA) recommended action level to address radon in the home. The average number of homes above 4pCi/L in some Montana counties ranges from 50-53%. Montana is ranked third in the nation with homes with levels above 20 pCi/L and is ranked fifth in the nation with homes with levels above 4 pCi/L. You cannot smell, see, or taste radon, but you can test for it. We recommend everyone test for radon. Read more here about radon in Montana homes. Visit the Montana Department of Environmental Quality's website for additional radon information.

Vapor intrusion

  • Some locations may result in an elevated risk of vapor intrusion from historic or off-site contamination. Ask your local health department if they know of any vapor intrusion risks in your neighborhood.  Learn more about vapor intrusion.


  • Mold exposures that occur over long periods of time (i.e., >1 year) can result in long-term health effects. Short-term exposures can induce asthmatic responses and even cause life-threatening conditions in immune-compromised individuals. If your home does have a mold problem, consider mitigating the hazard as soon as possible. Learn more about mold, mold growth, and how to control it.

Wood smoke

  • Indoor wood smoke from a poorly sealed wood stove or infiltration from poor outside air quality (e.g., wildfires during hot or dry seasons; wood stove wood smoke usage during cold seasons and during temperature inversions).

Outdoor smoke during prescribed or wildfire burning events. 

  • Studies show that in most buildings about 70-90% of outdoor smoke particulates levels are observed indoors. This means that the particulates can find ways to infiltrate your home. We recommend utilizing an ultrafine air filtration (e.g., HEPA) unit indoors to help provide a refuge from the smoke particles