“Safe” Air Pollution Levels are Scarring Your Heart.

A 2025 MRI study from the University of Toronto found that long-term exposure to even low levels of air pollution causes hidden heart damage, specifically increasing myocardial fibrosis—a form of scarring linked to future cardiovascular disease . Researchers examined over 690 participants, both healthy individuals and those with heart conditions, and found that fine particulate pollution (PM2.5) was associated with more fibrosis in all groups, especially women, smokers, and those with high blood pressure.

These harmful particles—found in car exhaust, industrial emissions, and wildfire smoke—are small enough to pass from your lungs into your bloodstream and embed in your heart tissue. Shockingly, the pollution levels in this study were below most international air quality guidelines, suggesting no level of PM2.5 exposure is truly safe.

Avoid busy roads, filter your air indoors, and push for clean air policies—your heart health might depend on it.