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Wildfire smoke exposure was not much worse than a bad pollen day in NYC

According to a recent study led by NYU Grossman School of Medicine, exposure to smoke from the Canadian wildfires in June 2023 led to only a slightly higher increase in visits to New York City hospital emergency departments for breathing problems or asthma attacks than what is usually seen on days when pollen counts are high. However, the experts warn that other possible health issues, such as heart attacks or strokes, still need to be assessed.

Focus of the study

The researchers analyzed daily levels of air pollution during the first six months of 2023 (including months of regular ambient air pollution and the days in June when wildfire smoke peaked), as measured by the presence of tiny particles known as PM2.5. If entering the lungs, such pollutants can lead to inflammation, as well as respiratory and heart problems. 

What the researchers learned 

The investigation revealed that wildfire smoke led to a three percent average increase in asthma-related visits to emergency departments across all the hospitals in New York City (for each 10 microgram increase in PM2.5 per cubic meter of air). 

On June 7, when wildfire smoke was at its worse (at a PM2.5 of 146 micrograms per cubic meter of air), asthma-related ER visits peaked at 335, up from a daily average of 188 per day. This number is only slightly higher than the 302 asthma-related emergencies seen on April 26, when the levels of air pollen – another major lung irritant and asthma trigger – was high (over 1,500 per cubic meter of air). 

“Thankfully, the respiratory effects of the wildfire smoke in June were not much worse than what had been seen on really bad pollen days back in the spring, and despite what many New Yorkers may have feared on seeing hazy, orange air,” said study co-author Wuyue Yu, a doctoral student at NYU Langone Health

Long-term consequences are unknown

These findings mirror those observed with rises in ambient air pollution and pollen seen elsewhere, and their effect on asthma-related ER visits. 

“Still, the long-term consequences, if any, of exposure to wildfire smoke remain unknown, so we are not yet totally in the clear,” said co-author David Luglio, another PhD candidate at the same institution.

Fossil fuel emissions

In future studies, the researchers aim to compare the health effects of exposure to wildfire smoke to particulate matter commonly inhaled from fossil-fuel combustion, which is more dangerous. 

“While inhaling any particle-filled air is not good for your lungs, we do know that wildfire smoke is primarily made up of organic matter,” said lead author George Thurston, a professor of Medicine and Population Health at NYU Langone. “As a result, it is not enriched in the toxic metals that are found in fossil-fuel emissions, which are known to cause damaging oxidative stress in the body.”

Study implications 

According to Thurston, since potassium is a key component of soil and foliage, wildfire smoke contains 64 percent more potassium than ambient air pollution. 

By contrast, wildfire smoke contains just 12 percent of the average levels of copper present in background air pollution and 26 percent of the average levels of sulfur observed in the ambient air. 

These hazardous substances are found in average New York City air and are well-known causes of oxidative stress when inhaled.

The study is published in the American Journal of Respiratory and Critical Care Medicine.

By Andrei Ionescu, Staff Writer

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