Can Even Low Levels of Air Pollution Scar the Heart? Study Provides Insight - Video

A new study published in Radiology, the journal of the Radiological Society of North America (RSNA), has found that prolonged exposure to fine particulate air pollution is associated with early signs of heart damage. Using advanced cardiac MRI, researchers discovered that even low levels of air pollution may contribute to diffuse myocardial fibrosis, a form of scarring in the heart muscle that often precedes heart failure.

Cardiovascular disease remains the leading cause of death worldwide, and while prior research has linked poor air quality to increased risk of heart attacks and other cardiovascular issues, the biological mechanisms behind this risk have remained unclear.

To explore this, the researchers used cardiac MRI, a noninvasive imaging method, to quantify myocardial fibrosis in relation to long-term exposure to PM2.5—fine particulate matter less than 2.5 micrometers in diameter, commonly emitted from vehicle exhaust, industrial activity, and wildfire smoke. The study included 201 healthy participants and 493 individuals with dilated cardiomyopathy, a condition that weakens the heart's ability to pump blood.

The findings revealed that both healthy individuals and patients with heart disease who had higher long-term exposure to PM2.5 showed increased levels of myocardial fibrosis. The strongest associations were found in women, smokers, and individuals with hypertension

The study suggests that integrating a patient’s air pollution exposure history into clinical evaluations could improve risk assessments and help address related health disparities.

“Public health measures are needed to further reduce long-term air pollution exposure,” said senior author Dr. Kate Hanneman, from the Department of Medical Imaging at the University of Toronto and University Health Network, emphasizing that current pollution levels—even those within global guidelines—may still pose health risks. The research also highlights the vital role radiologists can play in identifying environmental impacts on human health through imaging.

Reference: Jacques Du Plessis, Chloe DesRoche, Scott Delaney, Rachel C. Nethery, Rachel Hong, Paaladinesh Thavendiranathan, Heather Ross, Felipe Castillo, Kate Hanneman. Association between Long-term Exposure to Ambient Air Pollution and Myocardial Fibrosis Assessed with Cardiac MRI. Radiology, 2025; 316 (1) DOI: 10.1148/radiol.250331