Energy & Environment

Canadian wildfire smoke led to spike in asthma ER visits in Northeast US: CDC

A man talks on his phone as he looks through the haze at the George Washington Bridge in Fort Lee, N.J., June 7, 2023. (AP Photo/Seth Wenig)

The smoke from Canadian wildfires that engulfed U.S. cities this summer and turned New York City’s skies orange led to a spike in asthma-related visits to emergency rooms, the Centers for Disease Control and Prevention (CDC) revealed Thursday.

Smoke caused dangerously low air quality in cities across the U.S., but the impact was felt especially in the Northeast, a CDC study claims. Nationally, asthma-related ER visits increased by 17 percent in areas impacted by the smoke.

In New York and New Jersey, smoke caused 364 excess asthma ER visits, the study claims, all of which occurred around the early June wildfire smoke that dirtied New York City air to “very unhealthy” levels. Hospital traffic was 46 percent higher in those states on smoke days.

Those states saw five days this summer, the most of any region in the country, where air quality rose above 100 on the Environmental Protection Agency’s air quality index. Levels around 50 are considered normal, while any mark above 150 is considered “unhealthy for all groups.”

On June 8, New York City’s air quality index spiked to 257, considered “very unhealthy.”


“Yesterday New Yorkers saw and smelled something that had never impacted us on this scale before,” New York City Mayor Eric Adams said at the time. “We had dangerously high levels of wildfire smoke from thousands of miles away, from the gloom over Yankee Stadium to the smoky haze scouring our skyline. We could see it, we could smell it and we felt it.” 

A second CDC study focused on New York state alone, without New York City, found that hospital visits related to asthma increased by 82 percent on those most severe early June wildfire days, with the impact most severe in central New York.

Wildfire smoke contains large particles that can exacerbate already-present health conditions like asthma by irritating the lungs and other parts of the body.

People with asthma often wheeze, are breathless, have chest tightness and have either nighttime or early-morning coughing.

“I have no doubt that every asthmatic had an uptick in symptoms,” Dr. Adrian Pristas, a New Jersey pulmonologist, told The Associated Press. “Some were able to manage it on their own, but some had to call for help.”

The Mid-Atlantic and Appalachian region saw four days of significant wildfire smoke, but a smaller increase in asthma ER visits, according to the study. The Midwest saw smaller ER visit increases in four wildfire smoke days as well.

Canada is facing one of the most severe wildfire seasons in the country’s history. While fires in eastern and central Canada created the smoke that choked the Northeast U.S. earlier this year, now fires in British Columbia have threatened the air quality in the Pacific Northwest.