What Are the Health Risks of Wildfire Smoke Exposure?

A lot is still unknown about the toll wildfire smoke takes on your health. But most adults and children without pre-existing conditions will likely recover quickly from the effects of short-term exposure to the smoke passing over the United States, said Jeffrey Brook, an associate professor of occupational and environmental health at the University of Toronto Dalla Lana School of Public Health.

The smoke that people have encountered this week is one of many exposures to pollution our bodies will take in over time, he said — it’s not likely that we’ll be able to identify a health problem in the future and definitively pin it on a few days of wildfire smoke.

“The brevity of this exposure for this period of time shouldn’t have significant long-term effects for the general population,” said Dr. Panagis Galiatsatos, a pulmonary and critical care medicine physician at Johns Hopkins Medicine. But there’s limited data on how to assess the health effects from a “onetime big burst of smoke,” said Mary Prunicki, director of air pollution and health research at the Sean N. Parker Center for Asthma and Allergy Research at Stanford Medicine.

“What happens to the person that doesn’t have any outward symptoms from this brief exposure? Probably there are changes in their bloodstream, but maybe that’s transitory. We don’t actually know,” she said. “If they have no significant impacts acutely from the smoke, probably they’re going to not have long-term impacts. But research hasn’t actually shown that either way.”

Isolating the long-term effects of wildfire smoke in general is difficult — it’s tricky to determine how exposure to smoke can impact cognitive performance years later or other consequences, said Laura Corlin, an assistant professor at Tufts University School of Medicine. And we also don’t know the exact threshold for just how much exposure is likely to have a long-term impact, said Dr. Raj Fadadu, a researcher at the University of California, San Francisco School of Medicine who has studied the health effects of wildfire smoke.

What we do know is that even minutes of exposure to wildfire smoke can trigger inflammation in the body, said Dr. Brook. Inflammation can lead to a cascade of downstream health effects; the longer it persists, the more it raises the risk for cardiovascular issues and strokes. A few days or a week of enhanced inflammation is most likely not enough to lead to detectable health problems in the future, he said. “But inflammation is inflammation, and it is bad.”

We also know that wildfire smoke is particularly dangerous for people with underlying lung or heart conditions. Smoke can exacerbate symptoms of asthma and chronic obstructive pulmonary disease. It can put babies, children, older people and pregnant women at risk of severe health effects. Smoke also poses significant risk to fetuses. For otherwise healthy people without pre-existing conditions, even brief exposure to wildfire smoke can lead to stinging eyes, irritated sinuses, wheezing, shortness of breath, headaches, itchy skin and coughing.

If you go outside, wear a tightfitting mask like an N95, and pay extra attention to your body for the next hour or so that follows, said Dr. Emily Pennington, a pulmonologist at the Cleveland Clinic — watch out for symptoms like intense coughing and chest tightness. If you are struggling to breathe or experiencing chest pain, seek medical attention. Continue to monitor your health over the next few days, and make sure you’re staying hydrated and getting enough sleep, which might help you feel better, advised Dr. Corlin. And take whatever precautions you can to minimize your level of exposure — namely, staying inside as much as possible.