Here's who is most at risk from wildfire smoke and how to protect yourself

Adults with asthma and COPD

“Chronic lung conditions are caused in part by airway inflammation. Wildfire smoke induces inflammation, so it exacerbates those conditions,” explains Dr. John Balmes, a pulmonologist and professor emeritus of environmental health sciences at the University of California at Berkeley. A number of studies have found that people with asthma and COPD are more likely to visit the ER or be hospitalized after wildfire smoke exposure.

Some people also experience longer-lasting decreases in lung function. When researchers looked at data from patients at a North Carolina allergy clinic, they found decreases in peak respiratory flow one year after two separate fires had affected the area.

Bottom line: Because N95 masks can make it more difficult to breathe, opt for one with an exhalation valve, suggests Balmes. In addition to staying inside if the AQI is higher than 100, monitor your breathing with a peak flow meter. If you’re in the red zone and have taken your rescue bronchodilator medication, go to urgent care or the ER, says Balmes. If you’re checking your oxygen saturation with a pulse oximeter, go to the ER if it’s 84% or lower. (Beware: they don’t work as well on darker skin tones.)

If you're over 65: Watch for lung and cardiovascular risks

“Older people are more likely to have high blood pressure, heart problems, and other conditions that make them more vulnerable to the toxic effects of wildfire smoke,” says Harvard’s Johnson. A study published in the Journal of the American Heart Association in 2018 found that people over 65 were more likely to go to the ER with a range of cardiovascular problems, like heart attack, dysrhythmia, pulmonary embolism, and stroke, on or after dense smoke days. Research suggests that older women and Black people may be particularly susceptible to respiratory problems when exposed to wildfire smoke.

 Bottom line: If you have heart or lung problems, ask a neighbor to pick up your mail, take out your trash, or run errands for you when the AQI is above 150, and if you have to go outside, wear a tight-fitting N95 mask, says Balmes.

If you work outdoors

Farm workers. Construction crews. Bike messengers. Landscapers. Millions of people have outdoor jobs – and don’t get time off for smoky air. The work is often strenuous, which means they’re inhaling more PM2.5. While there’s little research assessing the effects on outdoor workers' health, it’s safe to assume regular exposure to unhealthy air takes a toll. The Occupational Safety and Health Administration’s says federal law entitles you to a safe workplace, and workers have a right to speak up about hazards or refuse to work in a hazardous situation.

The Centers for Disease Control suggests all employers relocate or reschedule work tasks to less smoky areas or times of day and encourage workers to take frequent breaks. Oregon, California, and Washington are the only states that have adopted rules for employers to limit employees’ exposure, including providing N95 masks to workers. But compliance, according to a 2021 investigation in California by KQED and the California Newsroom, is spotty at best.

Bottom line: Wear an N95 mask with an exhalation valve when you’re outside in smoky air, even if your employer doesn’t provide one.

Household pets

“If you’re feeling the impact of smoke, your pet is, too,” says Lori Teller, a veterinarian and a clinical professor at Texas A&M University College of Veterinary Science. “Coughing and gagging are signs they’re affected. Wildfire smoke can injure their lungs and, when the particles get in the bloodstream, cause damage to other organs.” Birds are extremely sensitive to smoke, because they take in almost double the amount of oxygen with each breath as mammals. Brachycephalic breeds, like French bulldogs, pugs, and Persian cats, have compacted respiratory tracts and may be more impacted by smoke, too.