The Impact of Air Pollution and Wildfire Smoke on Heart Health, Especially Heart Attacks (Acute Coronary Syndromes)

Air pollution is a major environmental factor that affects heart health. It includes tiny particles (PM₂.₅), gases like nitrogen dioxide (NO₂) and ozone (O₃), and other pollutants. Among these, fine particles (PM₂.₅) are most strongly linked to heart disease. In the past few years, wildfires have become a bigger concern because they produce large amounts of smoke and PM₂.₅, sometimes for days or weeks at a time, affecting people far from the actual fire.

Air Pollution and Heart Attacks

Breathing in polluted air can trigger inflammation and stress in the blood vessels, make the blood more likely to clot, and can destabilize cholesterol plaques in the arteries. These processes can lead to heart attacks, also known as acute coronary syndromes (ACS). Both long-term and short-term exposure increase risk.

A large analysis found that short-term spikes in PM₂.₅ were linked to about a 2–3% higher risk of heart attack (Mustafic et al., 2012). This shows that even a few days of poor air quality can have real impacts.

Wildfire Smoke and the Heart

Wildfire smoke is especially concerning because it can push PM₂.₅ levels very high over large regions. Studies in California have shown more hospital visits for heart attacks, heart failure, and even cardiac arrests during wildfire smoke periods (Delfino et al., 2009; Wettstein et al., 2018). People over 65 and those with heart disease seem to be most affected.

The health impact is likely caused by the same mechanisms as general air pollution: inflammation, oxidative stress, and changes in blood clotting and vessel function.

Protecting At-Risk Patients

For people with heart disease—or risk factors like diabetes, high blood pressure, or smoking—air quality matters. During heavy smoke days or high pollution alerts:

• Stay indoors as much as possible and use an air filter if available.

• Avoid strenuous outdoor activity.

• Monitor symptoms and seek care quickly if chest pain or shortness of breath develops.

Conclusion

Air pollution, including wildfire smoke, is an important and often overlooked trigger for heart attacks and other cardiovascular events. With wildfires becoming more common due to climate change, this is a growing public health concern.

References

• Brook RD, Rajagopalan S, Pope CA 3rd, et al. Particulate matter air pollution and cardiovascular disease: An update to the scientific statement from the American Heart Association. Circulation. 2010;121:2331–2378.

• Rajagopalan S, Al-Kindi SG, Brook RD. Air Pollution and Cardiovascular Disease. J Am Coll Cardiol. 2018;72:2054–2070.

• Mustafic H, Jabre P, Caussin C, et al. Main air pollutants and myocardial infarction: a systematic review and meta-analysis. JAMA. 2012;307:713–721.

• Delfino RJ, Brummel S, Wu J, et al. Respiratory and cardiovascular hospital admissions related to the southern California wildfires of 2003. Occup Environ Med. 2009;66:189–197.

• Wettstein ZS, Hoshiko S, Fahimi J, et al. Cardiovascular and cerebrovascular emergency visits during wildfire smoke exposure in California in 2015. J Am Heart Assoc. 2018;7:e007492.