New research finds a stark association between Canadian wildfire smoke and increases in the number of people being seen for asthma-related symptoms in New York City emergency departments.

The findings confirm that harmful smoke from wildfires is capable of traveling great distances and can impact the health of people hundreds of miles away.

With smoke from Canadian wildfires once again descending on the Northeastern United States, residents of New England and New York are being urged to take precautions to protect their health.

While the wildfire smoke is not expected to be as bad as the thick orange haze that permeated the skies over New York City and the New England states last June, a heightened risk for health problems remains—especially among those with certain respiratory conditions.

The new study, which appears in the Journal of the American Medical Association, is unique because previous studies on the health impacts of wildfire smoke have focused on areas near the wildfires, but not the broader global regions affected by drifting smoke.

Looking at data from June 2023, the researchers found there was a significant spike in ambient fine particulate matter (PM2.5) in the air over New York City during a smoke wave that dropped down from Canada over a three-day period from June 6 to June 8.

On the same days that the spike in PM2.5 pollution occurred over New York, emergency department visits for asthma-related symptoms jumped to 261 per day across the city, compared with an average of about 182 visits per day during reference periods identified by the researchers before and after the smoke wave. Both the fine particulate matter and the emergency room visits peaked on June 7.

PM2.5 pollution has been shown to affect respiratory health, cardiovascular health, birth outcomes, and mental health, says lead author Kai Chen, an assistant professor of epidemiology (environmental health sciences) at the Yale University School of Public Health.

The findings should be taken as a word of caution for people living in regions immediately affected by wildfires as well as those downwind from the fires, the scientists say.

Read the full article about health impacts of wildfire smoke at Futurity.