Long-Term Air Pollution Linked to More Advanced Coronary Artery Disease, Even at Low Levels
A study published in Radiology examined the relationship between long-term air pollution exposure and coronary atherosclerosis, finding that even moderate exposure levels are associated with more advanced coronary artery disease.
Key Findings
- Researchers analyzed data from 11,128 adults who underwent cardiac CT exams from 2012 through 2023 at three hospitals in Toronto.
- Patient residential postal codes were linked with air quality data to estimate average exposure to PM2.5 and NO2 over the 10 years prior to CT.
- Three markers of coronary artery disease were assessed: calcium score, total plaque burden, and obstructive stenosis.
The results were striking:
- For each 1 microgram per cubic meter increase in long-term PM2.5, there was an 11% increase in coronary calcium, 13% greater odds of more plaque, and 23% greater odds of obstructive disease.
- NO2 exposure showed similar but smaller effect sizes.
Context & Implications
- Air pollution is a leading environmental risk factor for cardiovascular disease globally.
- The study's median PM2.5 exposure was below current Canadian air quality standards.
- Previous research linked short-term exposure to emergency visits and hospital admissions, and long-term exposure to increased risks of myocardial infarction, stroke, and cardiovascular mortality.
What the Author Says
"Even at levels below regulatory standards, long-term air pollution was independently associated with more advanced coronary artery disease."
Dr. Kate Hanneman, senior author, noted that the findings suggest current regulations may not be fully protective. She added that air pollution should be considered a modifiable cardiovascular risk factor alongside blood pressure, cholesterol, and smoking.
The Bigger Picture
- The study suggests that reducing air pollution through policy, urban planning, and personal decisions can serve as a cardiovascular intervention.
- It also highlights the connection between air pollution and climate change, as fossil fuel combustion drives both.