Wildfire Smoke Exposure Associated With Decreased Asthma Control in Pediatric Patients

Wildfire smoke exposure in the Northeast US was shown to be associated with decreased asthma control among pediatric patients, wrote authors of research published in Environmental Health. The investigators urged that, as climate change continues to incite longer and more intense wildfire seasons, continued monitoring is vital to understanding the impact on pediatric respiratory health.¹

Asthma and Wildfire Smoke

Connections between climate change and human health are becoming increasingly clear, the authors said; however, gaps remain in research predicting and quantifying these specific relationships. The World Health Organization estimates that climate change will cause an additional 250,000 deaths annually from 2030 to 2050, with factors such as increasing temperature, loss of biodiversity, and more frequent extreme weather events. Together, these factors are likely to drive disease spread, increase hunger and malnutrition, and exacerbate existing health conditions.¹

Specifically, wildfire smoke is shown to have negative impacts on respiratory health. The authors wrote that, in the US, wildfire seasons have lengthened and intensified over the past decades and are predicted to continue worsening due to climate change. Prior research has already outlined the negative health impacts of wildfire smoke, which are more critical in vulnerable populations, including children and individuals with preexisting respiratory and cardiovascular diseases.¹

Among these chronic diseases is pediatric asthma. Over 4 million US children under the age of 18 years (6%) have asthma, and it disproportionately affects underresourced and minority children and adolescents. In the Northeast, childhood asthma rates are particularly concerning. For example, Vermont has the second highest rate of pediatric asthma in the country, meaning that affected youth are potentially vulnerable to smoke from distant wildfires. The authors wrote that this vulnerability was tested in the summer of 2023, when severe wildfires burned in Canada, sending dense smoke across the border into the Northeastern US.¹

“In 2023 when we couldn’t see New York across the lake, a lot of Vermonters began to worry about wildfire smoke,” lead author Anna Maassel, PhD candidate at the Rubenstein School of Environment and Natural Resources and graduate fellow at the Gund Institute for Environment, said in a news release. “A lot of people think of Vermont as a relatively safe place to live when it comes to climate change, but we found that smoke coming from hundreds of miles away affected children here.”²

Association Between Wildfire Smoke Exposure and Pediatric Asthma Control

This study further explored the relationship between airborne particulate matter (PM2.5) exposure from wildfire smoke and pediatric asthma control levels in Vermont and upstate New York during the summer of 2023. The investigators gathered data from electronic health records of individuals with asthma aged 3 to 21 years. All patients were from 1 health care system, and 3 clinical measures of asthma control were used depending on age: Test for Respiratory and Asthma Control in Kids (TRACK; 3–4 years); Asthma Therapy Assessment Questionnaire (ATAQ; 5–21 years); and the National Heart, Lung and Blood Institute (NHLBI) asthma control guidelines (3–21 years).¹

First, the investigators compared asthma control in the smoke-affected summer of 2023 to the largely unaffected summers of 2022 and 2024 using regression models, while controlling for pollen exposure. PM2.5 values were obtained within zip codes, and regression models were used to investigate the association between asthma control and PM2.5 during the study’s timeframe.¹

A total of 1217 encounters (mean age: 9.1 ± 4.4 years; 57% male) were used in the study. The investigators determined that 2 of the 3 asthma control assessments indicated significantly negative impacts of wildfire smoke in the year-to-year assessment, but there was no association found in the spatial analysis using ZIP code–level PM2.5 exposure. The exact mechanism of PM2.5 from wildfire smoke to promote asthma exacerbations is unclear, the authors reported, but is an active area of inquiry.¹

Specifically, TRACK scores did not worsen with increased PM2.5 (β = 1.09, 95% CI –0.95, 3.13; p = .290), ATAQ scores were not different as PM2.5 increased (β = -0.01, 95% CI, –0.07, 0.05, p = .801), and the odds of uncontrolled asthma using the NHLBI guideline charts were not associated with higher PM2.5 (β = 0.99, 95% CI, 0.91, 1.07; p = .716). Additionally, across the summer, the daily range in 4-week rolling average PM2.5 across ZIP codes spanned 5.8 to 18.0 µg/m³, with the smallest variation on August 20 and the largest on June 29. According to the investigators, this indicates that while all ZIP codes experienced distinct PM2.5 levels, the level of differences varied from day to day.¹

Taken together, these findings provide a range of mechanistic rationale for the examination of the influence of wildfire smoke exposure on asthma control.¹

“I think our findings suggest that there is potential for wildfire smoke, even hundreds of miles away, to impact a child's health,” coauthor Keith Robinson, MD, pediatric lung doctor at Golisano Children’s Hospital at the University of Vermont, said in the news release. “Clinicians need to make sure that parents and patients understand how to check for air quality, especially when there are wildfires in the area. We also need to make sure that patients and families who do not have the means to mitigate the effects of wildfire smoke have support from public health agencies.”²

The Pharmacist’s Role in Pediatric Asthma Care Amid Climate Change

Amid the growing respiratory risks posed by climate change–driven wildfire smoke, pharmacists play a significant role in protecting and optimizing pediatric asthma care. Because pharmacists are accessible health care professionals, they are available to educate families on monitoring air quality indices, recognizing early signs of asthma exacerbations during wildfires, and implementing asthma action plans proactively. They can reinforce proper inhaler technique, assess adherence to controller therapies, and recommend timely medication adjustments or refills during periods of poor air quality to prevent exacerbations. Pharmacists can also counsel caregivers on evidence-based mitigation strategies—such as limiting outdoor activity, using high-efficiency particulate air filtration when feasible, and appropriate use of rescue medications—while helping families navigate access barriers, particularly in underresourced communities disproportionately affected by asthma.

As wildfire seasons lengthen and exposure becomes more widespread, integrating pharmacists into pediatric asthma management and public health preparedness efforts is essential to maintaining asthma control and reducing climate-related health inequities.

REFERENCES

1. Maassel AK, Brochu P, Harder VS, Ricketts TH, Teach SJ, Robinson KJ. Wildfire smoke and pediatric asthma control in the Northeastern United States: a cross-sectional study. Environ Health. 2025;24(1):91. Published 2025 Dec 11. doi:10.1186/s12940-025-01245-9

2. University of Vermont. Canadian wildfire smoke worsened pediatric asthma in US Northeast: UVM study. News release. December 11, 2025. Accessed December 22, 2025. https://www.eurekalert.org/news-releases/1109392