Traffic pollution linked to hardened arteries

The closer people live to roads with heavy traffic and high air pollution, the greater their risk of developing hardened arteries, which may lead to heart disease and stroke, according to a study.

People living within 160 feet of heavy traffic are 63 percent more likely to have the highest levels of plaque buildup on their artery walls than those who live more than 200 meters from major roads, German researchers reported today in the American Heart Association's journal Circulation.

The research is the first to show why air pollution might trigger heart failure, heart attacks, strokes and deaths related to heart disease, the researchers said. The buildup, called coronary atherosclerosis, results in heart disease, which kills more than 7 million people worldwide each year, according to the U.S. Centers for Disease Control and Prevention in Atlanta.

"Coronary atherosclerosis is the underlying pathology for the events people suffer from, like sudden cardiac death," said Barbara Hoffmann, the study's lead author and a researcher at the Institute for Medical Informatics at the University of Duisburg- Essen in Essen, Germany.

Coronary atherosclerosis causes complications when plaque on artery walls blocks blood flow. The researchers tested the amount of hardened calcium in the arteries of about 4,500 German adults, ages 45 to 74. They determined the levels of exposure by measuring the pollution from busy roads in cities located in the Ruhr area of western Germany and gauging the distance from the participants' homes.

"It's a large, metropolitan area with lots of traffic and industry," said Hoffmann. "Air pollution is a major concern."

The amount and makeup of air pollution depends on how heavy the traffic is and what kinds of vehicles are on the road, researchers said. In Germany, 18 percent of vehicles have heavy- duty diesel engines, and almost 20 percent of passenger cars run on light-duty diesel engines, according to the study.

The proportion of such vehicles is smaller in the U.S., 3.6 percent in 2005, according to the Diesel Technology Forum, a nonprofit industry group based in Frederick, Maryland.