New research from the University of Vermont suggests smoke from Canadian wildfires in the summer of 2023 made asthma symptoms worse for children in Vermont and upstate New York.
In certain respects, these new findings are not surprising. Prior research on wildfire smoke “overwhelmingly” points to negative repercussions on health, particularly in children, according to Anna Maassel, the study’s lead author and a doctoral student at UVM’s Rubenstein School of Environment and Natural Resources.
But comparatively little research has looked into wildfire’s public health impacts on populations far away from the blaze, she said. More often, studies have examined the effects of intensely poor air quality over long periods of time.
The UVM study, published in December in Environmental Health, was the first to look at the impacts of wildfire smoke on asthma in the Northeast, the university said.
“This shows that even these small levels of changes in air quality due to wildfire smoke have that same impact of negatively impacting children's health,” Maassel said.
Climate change is expected to continue bringing more wildfire smoke to New England. The main pollutant in wildfire smoke is PM2.5 — tiny particles that penetrate deep into lung tissue and worsen respiratory conditions like asthma, among other health effects.
About 7% of youth in Vermont have asthma, according to the Vermont Department of Health.
Researchers studied electronic health records for more than 900 people, aged 3-21, being treated for asthma within the University of Vermont Health Network over three summers, from 2022 to 2024. They then compared this with estimated smoke exposure within zip codes, based on air quality data.
They found that children’s asthma in Vermont and New York was markedly less well-controlled in 2023, when Quebec experienced a record-breaking wildfire season, compared to 2022. But researchers didn’t find that asthma symptoms noticeably improved between 2023 and 2024, even though air quality got better.
Maassel said more research is needed to understand why children’s asthma wasn’t better controlled in 2024. It’s possible, she said, that the wildfire exposures of 2023 had a lingering impact.
The researcher said she’s also interested in studying who is most impacted by smoke pollution — and what practical solutions public health officials can offer people to help protect them. Often, health officials tell vulnerable people to go inside and turn on their central air when air quality goes down. But few Vermonters have that option.
“What recommendations, what public health guidance or changes do we need to keep Vermonters safe?” she said.
