Study: Pollution Raises Exercise Risks

Study Says People With Heart Disease Should Exercise Indoors to Avoid Breathing Polluted Air


By LINDA A. JOHNSON Associated Press Writer
Sep 12, 2007 (AP)

People with heart disease may want to steer clear of heavy traffic when exercising or simply take their workout indoors to avoid breathing polluted air.

Exercising in areas with high levels of diesel exhaust and microscopic soot particles is especially risky for people with heart disease, according to the first study in which heart patients were directly exposed to pollution.

European researchers found that brief exposure to diluted diesel exhaust during exercise reduced a key anticlotting substance in the blood and worsened exercise-induced ischemia, or insufficient flow of blood and oxygen to the heart changes that can trigger a heart attack and even death.

"We now have evidence that being exposed to diesel fuel during exercise will cause cardiac ischemia and that if you have heart disease, it can only make things worse," said Dr. Abraham Sanders, a lung specialist at New York-Presbyterian Hospital who was not involved in the study.

The results have big implications: About 16 million Americans have heart disease, according to the American Heart Association. In addition, people with asthma, bronchitis and chronic obstructive pulmonary disease also should use caution and avoid polluted air when exercising, Sanders recommended. But heart and respiratory patients should keep exercising regularly because it is so beneficial to overall health, doctors stress.

Numerous studies have shown a link between short-term and long-term exposure to air pollution and higher rates of hospitalizations and deaths due to poor blood supply to the heart, abnormal heart rhythms, gradual heart failure and stroke.

This study adds to that knowledge about how air pollution harms people and aims to show what pollution is doing in the body, information that might eventually give clues for preventing such problems, said Dr. Howard M. Kipen, director of clinical research at Rutgers University's Environmental and Occupational Health Sciences Institute.

"It's quite amazing, what they found," but not a surprise, he said. Still, "most doctors aren't aware that little bits of pollution can cause heart attacks."