New Study Finds Urban Pollution Triggers Heart Attacks

by Jessica Berman

Oct 21, 2004 Washington - If you want to prevent heart disease, experts say don't smoke, eat sensibly and exercise regularly. But it's hard to avoid what appears to be another risk factor: urban traffic. In an article published this week in the New England Journal of Medicine, researchers found that people exposed to urban pollution in the form of vehicle emissions were significantly more likely to suffer heart attack than those for whom traffic congestion was not part of their daily life.

A new study concludes that breathing air particles from vehicle exhaust may actually trigger a heart attack in people who are trying to lead a healthy life style.

Researchers at Germany's National Research Center for Environment and Health in Neuherberg surveyed nearly 700 people, between the ages of 25 and 74, who lived in the city of Augsberg and two nearby rural areas who had suffered non-fatal heart attacks. Investigators found on average that drivers, bus riders and bicyclists who navigated city streets suffered three times as many heart attacks as those who lived in rural areas. The heart attacks among urban drivers and riders for the most part occurred shortly after being exposed to city traffic.

Sidney Smith, a professor of medicine at the University of North Carolina, says the results clearly implicate air pollution as the cause of the heart attacks.

"It suggests that exposure to particulate matter among those in traffic actually is a triggering mechanism; that within one hour of exposure to pollutants there was a three fold increase in myocardial infarction," he noted. "The interesting thing you would say is, 'It's the stress of riding a car.' But people riding in buses, anyone exposed to environmental pollution of this nature, seemed to be at risk."

Heart attack, a leading cause of death around the world, occurs when blood clots choke off circulation to the heart. The clots are released by blood vessels that have become irritated by high blood pressure and accumulations of cholesterol. Dr. Smith says studies of animals have shown that particulate matter is also an irritant. He says the latest findings put a human face on the hazards of air pollution.

"So, that's sort of the tie between this population study where in southern Germany they're seeing a significant relationship [between]the basic science in trying to understand what might be going on," he added.

Source: Voice of America