Long-term exposure to air pollution may lead to early heart damage, according to a new study published in the journal Radiology.
Researchers found that fine particulate matter in the air is associated with a type of heart scarring called diffuse myocardial fibrosis, which can develop into heart failure over time.
Cardiovascular disease is the number one cause of death worldwide. Previous studies have shown that poor air quality increases the risk of heart disease, but the exact changes in the heart caused by pollution were not well understood.
This study, led by Dr. Kate Hanneman from the University of Toronto, aimed to uncover those changes at the tissue level using cardiac MRI scans.
The team studied 694 people, including 201 healthy individuals and 493 patients with dilated cardiomyopathy—a heart condition that makes it harder for the heart to pump blood.
They used MRI to look for myocardial fibrosis and compared it to the participants’ exposure to PM2.5, a type of air pollution made up of tiny particles 2.5 micrometers or smaller. These particles can come from sources like car exhaust, factories, and wildfire smoke, and are small enough to enter the bloodstream through the lungs.
The results showed that people with higher long-term exposure to PM2.5 had higher levels of heart scarring, even if they were otherwise healthy. This suggests that air pollution may play a key role in causing hidden damage to the heart. The strongest effects were seen in women, smokers, and people with high blood pressure.
The findings highlight that even low or moderate levels of pollution can have serious health effects. Dr. Hanneman noted that the pollution levels in the study were still within current global air quality guidelines, indicating that even so-called “safe” levels of exposure may not truly be safe.
This study adds to growing evidence that air pollution should be considered a major risk factor for heart disease—on par with smoking and high blood pressure. Understanding a patient’s history of pollution exposure could help doctors better assess their heart disease risk and take steps to prevent future problems.
For example, people who work or live in areas with poor air quality could be flagged for additional screening or preventive care. Dr. Hanneman emphasized the need for stronger public health efforts to reduce pollution and protect heart health.
In addition to its health findings, the study also highlights the value of medical imaging in identifying the effects of environmental exposures on the body. “Radiologists have a major role to play in showing how air pollution impacts our organs,” said Dr. Hanneman. “Imaging can be a powerful tool for tracking and understanding these environmental risks.”
The research reinforces the urgent need for global action to lower pollution levels—even small improvements could make a big difference for heart health.
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The study is published in Radiology.
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