Prolonged exposure to wildfire smoke raises heart health risks

A new study from Yale researchers reveals that prolonged and cumulative exposure to wildfire smoke raises the risk of hospitalization for cardiovascular disease in older adults in the United States. As the climate changes, wildfires are becoming larger, more frequent, and more intense, leading to smoke that can travel hundreds of miles.

The researchers analyzed data from over 65 million Medicare beneficiaries across the continental US between 2017 and 2022. They found that even relatively low levels of smoke exposure over a few years were associated with a higher risk of hospitalization for conditions such as ischemic heart disease, irregular heart rhythms, stroke, and heart failure.

Study author Kai Chen, an associate professor of epidemiology at Yale School of Public Health, emphasized that the cardiovascular impacts of wildfire smoke extend well beyond the immediate fire zones and beyond the day the sky turns orange. While much previous research has focused on the immediate respiratory effects of wildfire smoke, this study highlights the long-term cardiovascular consequences.

Heart failure showed the strongest association, with risk increasing by more than 20% at higher exposure levels. Stroke risk, particularly ischemic stroke, also rose with increasing smoke exposure. The study found that even modest smoke levels can pose a cardiovascular risk, and low socioeconomic status may amplify the vulnerability to these health risks.

The researchers suggest that treating wildfire smoke as more than a short-term respiratory issue is crucial, and that public health measures should include timely alerts, clean-air spaces, and accessible filtration systems, particularly for communities with fewer resources.