Air pollution may lead to a dangerous narrowing of neck arteries, increasing the risk for stroke, new research shows.
 

The findings, by medical investigators from NYU Langone Medical Center, are based on reviews of medical records of more than 300,000 people living in New York, New Jersey, and Connecticut.

They found that people living in areas with the highest levels of fine-particulate-matter pollution were far more likely to show signs of narrowing (stenosis) in their internal carotid arteries, compared to those living in zip codes with the lowest pollution levels.
 

The study, to  be presented at the American College of Cardiology's 64th Annual Scientific Session and published online in the Journal of the American College of Cardiology, is the latest to sound new alarms on fine particulate matter pollutants — also called "PM 2.5 pollutants" — that are mostly by-products of combustion engines and burning wood.
 

"We spend a lot of time thinking about traditional risk factors for stroke such as high blood pressure, cholesterol, diabetes, and smoking — but our data underscore the possibility that everyday air pollution may also pose a significant stroke risk," said Jeffrey S. Berger, M.D., an assistant professor in NYU Langone Medical Center in the Department of Medicine.
 

Since the 1950s, episodes of high air pollution have been linked to spikes in local heart attack and stroke cases, but more recent studies have linked heart attack and stroke risks to long-term pollution exposures.
 

"Most of the studies in this area have focused on the heart and the coronary arteries; no one has really looked at other parts of the vascular system, in particular the carotid arteries," said Jonathan D. Newman, M,D,, a cardiologist at NYU Langone Medical Center.
 

The researchers' analysis showed that people living in highly polluted areas were about 24 percent more likely to have shown signs of stenosis.
 

"Our study was a population study, so it can't establish cause and effect, but it certainly suggests the hypothesis that lowering pollution levels would reduce the incidence of carotid artery stenosis and stroke," said Dr. Newman.