Dataset Information
Long-Term Wildfire Smoke Exposure and Increased Risk of Heart Failure in Older Adults.
Ontology highlight
ABSTRACT: Background
Fine particulate matter, defined as particles <2.5 μm in diameter (PM2.5), is the most important environmental risk factor for global mortality. Wildfires have been increasing globally, posing a global health challenge. Fire smoke-specific PM2.5 is believed to have more cardiovascular toxicity compared with other PM2.5 sources; however, the impact of fire smoke PM2.5 and heart failure (HF) remains undefined. We sought to investigate the association between long-term exposure to fire smoke PM2.5 and HF and compare it with nonfire PM2.5 in a large national cohort.Objectives
This study sought to evaluate the association between long-term exposure to wildfire smoke PM2.5 and the risk of incident HF among older adults across the contiguous United States.Methods
This retrospective cohort study analyzed data from Medicare fee-for-service beneficiaries between 2007 and 2018. We linked individuals to high-resolution exposure estimates of fire smoke and nonfire smoke PM2.5 at a 1 × 1-km spatial resolution that were aggregated to ZIP (Zone Improvement Plan) codes by averaging the values of all 1-km grid cells whose centroids fell within each ZIP code boundary and followed them for incident HF. The relationship between PM2.5 and incident HF were examined using Cox proportional hazard models, adjusting for individual demographic characteristics and area-level socioeconomic risk factors.Results
The cohort included approximately 22 million fee-for-service enrollees, with a follow-up totaling 115 million person-years. The mean smoke PM2.5 exposure, calculated as the average of all past 2-year moving average exposures across person-years, was 0.51 μg/m3. The HR associated with each 1-μg/m3 increase in the past 2-year average smoke PM2.5 was 1.014 (95% CI: 1.007-1.020), which was notably higher than the corresponding HR for nonsmoke PM2.5 (1.005; 95% CI: 1.003-1.006). This association corresponds to an estimated 20,238 (95% CI: 10,727-29,612) additional heart failure cases annually among U.S. older adults. Additionally, the number of days exposed to smoke PM2.5 exceeding 1 μg/m3 and 2.5 μg/m3 over the past 2 years were both significantly associated with an elevated risk of HF. We additionally found that the association between smoke PM2.5 and HF was stronger in women, Medicaid-eligible individuals, and those living in lower income areas, indicating higher susceptibility.Conclusions
In this national cohort, long-term exposure to fire smoke-related PM2.5 was linked to a higher risk of HF compared with nonsmoke PM2.5, with greater susceptibility in women and socially vulnerable populations. These findings underscore the need for targeted interventions and policies to reduce wildfire smoke exposure and its cardiovascular impacts.
SUBMITTER: Hao H
PROVIDER: S-EPMC12367337 | biostudies-literature | 2025 Jul
REPOSITORIES: biostudies-literature
Publications
Long-Term Wildfire Smoke Exposure and Increased Risk of Heart Failure in Older Adults.
Journal of the American College of Cardiology 20250701 25
<h4>Background</h4>Fine particulate matter, defined as particles <2.5 μm in diameter (PM<sub>2.5</sub>), is the most important environmental risk factor for global mortality. Wildfires have been increasing globally, posing a global health challenge. Fire smoke-specific PM<sub>2.5</sub> is believed to have more cardiovascular toxicity compared with other PM<sub>2.5</sub> sources; however, the impact of fire smoke PM<sub>2.5</sub> and heart failure (HF) remains undefined. We sought to investigate ...[more]
