Wildfire Smoke PM2.5 Linked to Cardiovascular Hospital Risks
Publication Title: Impact of Long-Term Cumulative Exposure to Wildfire Smoke PM2.5 on Cardiovascular Hospital Admissions Among Older Adults in the United States A Population-Based Cohort Study
Summary
- Question
- This study investigated the relationship between long-term exposure to fine particulate matter (PM2.5) from wildfire smoke and hospital admissions for cardiovascular disease (CVD) among older adults in the United States. The researchers aimed to assess how different exposure levels and individual characteristics, such as socioeconomic status, might influence the risk of CVD hospitalization.
- Why it Matters
- Wildfires are becoming more frequent and severe due to climate change, releasing fine particulate matter (PM2.5) into the air. These tiny particles, which are small enough to be inhaled deeply into the lungs, are known to cause inflammation and other harmful effects on the body. Cardiovascular diseases are a leading cause of death worldwide, and understanding how wildfire smoke affects heart and blood vessel health is critical. This research highlights the health risks posed by increasing wildfire smoke exposure and could inform public health strategies to protect vulnerable populations, particularly older adults.
- Methods
- The researchers conducted a population-based study of 65.2 million Medicare beneficiaries aged 65 and older across the contiguous United States between 2017 and 2022. They estimated wildfire smoke PM2.5 exposure levels using advanced models that combined satellite data and ground measurements, focusing on average exposure over three years. Hospitalization data for CVD and its subtypes, such as heart failure and stroke, were analyzed using statistical models to explore associations with PM2.5 exposure.
- Key Findings
- Long-term exposure to wildfire smoke PM2.5 was linked to an increased risk of hospitalizations for CVD. The risk peaked at moderate exposure levels (0.26–0.32 micrograms per cubic meter) for overall CVD, ischemic heart disease (reduced blood flow to the heart), and arrhythmias (irregular heartbeats). For cerebrovascular disease (affecting blood flow to the brain), the risk increased steadily with higher exposure levels. Individuals with lower socioeconomic status appeared to be more vulnerable to these effects.
- Implications
- These findings suggest that even moderate exposure to wildfire smoke can harm cardiovascular health, emphasizing the need for targeted interventions to reduce exposure and mitigate risks. Public health measures, such as air quality alerts and clean air shelters, could help protect older adults and socioeconomically disadvantaged populations. Clinicians may also consider incorporating wildfire smoke exposure into cardiovascular risk assessments.
- Next Steps
- The authors recommend further research to explore the mechanisms linking wildfire smoke to specific types of cardiovascular disease. They also suggest studying the effectiveness of public health interventions and protective measures to reduce the health impacts of wildfire smoke.
- Funding Information
Yale University provided support and funding.
Full Citation
Zhang S, Wang Y, Wei J, Benmarhnia T, Liu Y, Krumholz H, Lu Y, Chen K. Impact of Long-Term Cumulative Exposure to Wildfire Smoke PM2.5 on Cardiovascular Hospital Admissions Among Older Adults in the United States A Population-Based Cohort Study. Journal Of The American College Of Cardiology 2026 PMID: 41706074, DOI: 10.1016/j.jacc.2025.12.079.
This AI-assisted summary has been reviewed and approved by at least one of the study's authors to ensure it accurately reflects the research.
Authors
Siqi Zhang
First AuthorAssociate Research Scientist
Kai Chen, PhD
Last AuthorAssociate Professor of Epidemiology (Environmental Health Sciences)
Additional Yale School of Medicine Authors
Other Authors
Research Themes
Concepts
- Exposure levels;
- Fine particulate matter;
- Occurrence of wildfires;
- Cardiovascular hospital admissions;
- Moderate exposure levels;
- Smoke PM2.5;
- Quasi-Poisson regression;
- Particulate matter;
- Smoke PM;
- Health risks;
- Wildfire;
- Medicare beneficiaries;
- Contiguous United States;
- Older adults;
- Cardiovascular disease;
- Cerebrovascular hospitalization;
- Relative risk;
- Hospitalization risk;
- Cohort study;
- Population-based cohort study;
- Spatiotemporal model;
- Residential zip;
- CVD hospitalizations;
- Overall CVD;
- Low socioeconomic status