Wildfire smoke and pediatric asthma control in the Northeastern United States: a cross-sectional study.

BACKGROUND: Poor air quality due to smoke from distant wildfires is a growing risk for the Northeastern United States, a region largely unaffected by these events until recently. Despite this emerging threat, few studies have examined the effect of wildfire smoke on respiratory health in this region. We investigated the association between wildfire smoke exposure and pediatric asthma control in Vermont and upstate New York. METHODS: We extracted data from the electronic health records of youth aged 3-21 years diagnosed with asthma within a single regional healthcare system and included three clinical measures of asthma control: Test for Respiratory and Asthma Control in Kids (3-4 years), Asthma Therapy Assessment Questionnaire (5-21 years), and the National Heart, Lung and Blood Institute (NHLBI) asthma control guidelines (3-21 years). We first compared asthma control in the smoke-affected summer of 2023 to the largely unaffected summers of 2022 and 2024 using regression models, controlling for pollen exposure. We then obtained airborne particulate matter (PM2.5) values within ZIP codes and used regression models to investigate the association between asthma control and PM2.5 during the smoke-affected summer of 2023. RESULTS: The study sample included 1,217 encounters (mean age 9.1 ± 4.4 years, 57% male). Asthma control was significantly worse in the severely smoke-affected summer of 2023 versus 2022 for two of the three clinical measures but was not different between 2023 and 2024 for any of the clinical measures. Within summer 2023, there were no significant associations between ZIP code-level PM2.5 and asthma control for any of the three clinical measures. CONCLUSIONS: Wildfire smoke exposure in the Northeast was associated with decreased asthma control in this pediatric population, though not consistently across years and all clinical measures. As climate change drives longer and more intense wildfire seasons, continued monitoring is needed to understand the impact on pediatric respiratory health in this historically low-exposed region.