Long-Term Wildfire Smoke Exposure May Increase Heart Failure Risk in Older Adults

Recent research indicates that prolonged exposure to wildfire smoke can lead to an increased risk of developing heart failure (HF), particularly among older adults, women, and vulnerable populations. Published in the Journal of the American College of Cardiology, the study titled "Long-term Wildfire Smoke Exposure and Increased Risk of Heart Failure in Older Adults" is the first comprehensive population-based analysis of wildfire smoke’s impact on heart health.

The research highlights that as wildfire smoke pollution levels rise over time, so does the risk of heart failure. This is particularly concerning given global environmental changes that are making wildfires more frequent and intense. Wildfire smoke contains PM₂.5 particles—tiny, inhalable particles measuring 2.5 micrometers or less in diameter—which can penetrate deep into the lungs and enter the bloodstream, posing significant health threats.

According to lead researcher Hua Hao, Ph.D., from Emory University's Rollins School of Public Health, "Even small increases in smoke pollution over time can substantially elevate heart health risks, especially in vulnerable groups." The study examined how frequently individuals were exposed to elevated levels of wildfire smoke, measured by days when PM₂.5 levels exceeded 1 or 2.5 micrograms per cubic meter.

The findings revealed that every 1-microgram-per-cubic-meter increase in wildfire smoke PM₂.5 levels over two years correlated with a 1.4% rise in the risk of heart failure among Medicare beneficiaries. The researchers estimate this increase could be associated with over 20,000 additional HF cases yearly in the United States among older adults. Notably, the association was stronger in women, Medicaid recipients, and residents of lower-income areas, indicating higher susceptibility in these groups.

In contrast, non-wildfire air pollution showed a much smaller increase in HF risk—only about 0.5% per similar pollution level increase—suggesting wildfire smoke may be more toxic per unit of exposure. Experts warn that climate projections predict a substantial rise in wildfire seasons and fire frequency worldwide, which could exacerbate these health risks.

Prominent epidemiologist Joan A. Casey from the University of Washington emphasized the urgency of addressing this issue, stating that "by the end of the century, increased wildfire activity will significantly extend fire seasons and intensify exposure, heightening public health concerns."

Medical professionals such as Dr. Harlan Krumholz from Yale highlight the importance of recognizing long-term wildfire smoke exposure as a serious heart health threat, urging both environmental policy changes and healthcare preparedness to mitigate its impact. The study also acknowledges limitations, including potential measurement errors and unaccounted individual risk factors.

This research underscores the critical need for preventative strategies to protect at-risk populations from the growing threat of wildfire smoke pollution, emphasizing that even long-term, low-level exposure can have serious cardiovascular consequences.