Caroline Ahn lives and works in the city. She also works out in the city. Ahn runs 5 to 7 miles about five times a week. Her route takes her from her home in West Town to the lakefront. But it also takes her through a highly polluted area.
“During the summer there is so much exhaust,” said Ahn, 26. “It’s very hot and the air becomes very thick.”
Ahn runs early in the morning to avoid the heat and the heavy traffic. And by running early on the lakefront, she also may be avoiding pollutants.
Chicago has comparable pollution problems to other major cities, said Bob Swinford, the supervisor for the Illinois Environmental Protection Agency’s air-quality unit.
The two main sources of Chicago’s pollution are ozone and fine particulate matter. These sooty sources come from traffic, power plants and industrial facilities, Swinford said.
Exercising in polluted areas can be a health risk, and Chicagoans aren’t immune. When running or cycling hard, the lungs pull in 10 times more oxygen. “Your lungs have to work harder, and your heart has to work harder,” said Dr. Norman H. Edelman, chief medical officer for the American Lung Association.
Pulling in more oxygen means pulling in more pollution. Normal lungs may not feel an immediate effect, but Edelman said there is evidence that pollution reduces lung function.
Outdoor exercisers with asthma may have a “lung attack” if working out vigorously in polluted areas, according to Edelman. There are ways to reduce pollution exposure, but it depends on your location.
In the city, Swinford said, the ozone level is a bit lower than in the suburbs. But the city has a higher level of fine particulate matter. These levels are higher at night and early morning. “It’s weather-pattern issues because it’s more calm at night,” Swinford said.
Running along the lakefront, like Ahn, may help reduce exposure to fine particulate matter. “Along the lake, you’re little bit away from the traffic influence, and you do get some lake air, which may be cleaner,” Swinford said.
The Loop, however, has different challenges. While the lake can bring in fresh air, Loop exercisers are cruising through the city’s most congested traffic area. But working out early or late won’t make a difference. In the Loop, Swinford said, it’s about weather, not time of day.
Cool, rainy days are best for exercise in the Loop, while hot or windless days are the worst. “The pollutants tend to build up under calm conditions,” Swinford said.
Chicago is heading into a better time of year, because the pollution situation improves in spring and fall. During summer and winter, Swinford said, conventional power plants are working extra hard to provide cooling and heating and thus sending out more pollutants.
Suburban athletes, however, have a different challenge. The level of fine particulate matter is lower than in the city, but the ozone levels are higher. The northern suburbs along the lakefront have the highest ozone concentration in the area, Swinford said.
Avoiding high ozone levels means scheduling your workout around the peak times. “Ozone tends to peak from the late morning until early evening,” Swinford said, “from noon until 6 or 7 at night.”
Suburban runners also can check daily ozone reports. Edelman recommends avoiding high-ozone days, especially if a person has a history of lung problems. “They will experience irritation of the chest or other symptoms of ozone pollution,” Edelman said.
Daily air-quality forecasts from the federal Environmental Protection Agency are available online at www.epa.state.il.us/air/aqi/index.html and break down the Chicago area by region.
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Study shows diesel cuts blood to heart
Men with stable heart disease who were exposed, even briefly, to diesel fumes in a Scottish study showed reduced blood flow to their hearts, increasing their risk of cardiovascular problems, including heart attacks.
The levels of pollution simulated in the study were similar to those found in regular city traffic.
“There is substantial evidence that exercise reduces a person’s lifetime risk of developing coronary heart disease, and we would encourage patients with heart disease to undertake regular exercise,” said study co-author Dr. Nicholas Mills, a specialist registrar in cardiology in the Centre for Cardiovascular Sciences at the University of Edinburgh. “We would suggest, however, that wherever possible, patients avoid exercising in heavy traffic.”
“This makes it clear that there’s almost a switch that can turn on and off when a person is exposed to diesel fuel,” said Dr. Len Horovitz, a pulmonary specialist with Lenox Hill Hospital in New York City. “Don’t jog behind a bus. Don’t jog in heavy traffic.”
— HealthDay News
