Smoke-filled air from Western state fires has darkened Utah skies for more than a week. For those with underlying airway disease, such as asthma and chronic obstructive pulmonary disease, or those suffering from heart disease or who have had a stroke, exposure to severe air pollution can cause life-threatening consequences. In fact, when the Air Quality Index tops 100, meaning “unhealthy for sensitive groups,” those with the aforementioned conditions should limit outdoor activity and avoid strenuous outdoor exercise.

Air pollution from fires is more than just the particles that we see. Smoke particles include both PM10 (large particles) and PM 2.5 (small particles). Large particles are filtered by the nose and don’t make it all the way to the lungs and blood vessels, whereas the smaller particles do get through and are responsible for the inflammation that worsens heart and lung disease. Additionally, other chemicals, such as nitrogen oxides, carbon monoxide and hydrocarbons, along with chemical reactions increasing ground-level ozone, add to the air pollution burden.

Even among “healthy people,” smoke pollution irritates eyes, noses and throats and can cause people to cough. However, it is our at-risk populations who should make intentional efforts to avoid exposure to smoke pollution. In addition to those with heart and lung disease, or history of stroke, those with diabetes should limit their exposure (given higher risk of cardiovascular disease).

Children are another at-risk group. They tend to spend more time outdoors playing and breathe faster, carrying air pollution particles deeper into their airways. Older adults are considered at greater risk, as they tend to have a higher burden of chronic disease, including heart and lung disease. Finally, pregnant women should take care to limit exposure to outdoor air pollution, as particle pollution is associated with preterm delivery and lower birth weights.

Aside from irritation of eyes, nose and throat, breathing difficulties such as wheezing, cough or shortness of breath may occur, and should prompt people to remove themselves from the smoky environment and follow their physician’s medical advice (e.g. using inhalers or other medications) or asthma action plan. In people with heart disease, chest pain, irregular heart rhythm or palpitations, shortness of breath or significant fatigue should prompt people to reach out to their medical provider.

Better is to avoid exposure to smoke-filled air. Keep an eye on the Air Quality Index, which can be found on the Division of Air Quality’s website (www.air.utah.gov/), or download the free UtahAir or airnow.gov apps to your smartphone. For those with underlying disease or at risk, exercise indoors when the AQI exceeds 100. Even for healthy people, when the AQI hits 150, air quality is considered unhealthy for everyone, and we should all limit prolonged exposure to outdoor air.

Finally, we can all do our part by not adding to the air pollution burden. Car pool, use public transportation, link trips and avoid idling.

Air pollution is everyone’s responsibility. Find out ways to do your part at UCAIR.org.

Elizabeth Joy, M.D., MPH, is medical director of community health at Intermountain Healthcare. Steve Bergstrom is director of sustainability at Intermountain Healthcare. Thom Carter is executive director of UCAIR. Debbie Burney-Sigman, Ph.D., is director of Breathe Utah.