Your Body on Bad Air
Pollution affects more than just your airways, says former air pollution scientist Kenneth Rundell, Ph.D. When you inhale airborne contaminants, your body launches a defense against “foreign invaders,” which then causes inflammation. Over time, chronic inflammation can wreak havoc on every organ system. So it’s not surprising that long-term exposure to bad air has been linked to a host of health problems—ironically the very conditions that regular exercise helps prevent—including high blood pressure, heart attack, stroke, type 2 diabetes, decreased immune function, and certain cancers. One Canadian research team mapped levels of traffic-related air pollution in Montreal against breast-cancer diagnoses. They found that women living in locations with the worst air pollution were almost twice as likely to develop breast cancer as those in the cleanest areas, says Mark S. Goldberg, Ph.D., one of the researchers and a professor in the department of medicine at McGill University.
If all this makes you want to strap on a gas mask every time you head outside, take comfort in this: Your lungs have several built-in cellular cleaning mechanisms that help neutralize irritants and rid the body of them, so you’ll most likely recover pretty quickly from an occasional dose of dirty air.
The bigger concern is what happens after years of repeated exposure. In fact, the Environmental Protection Agency likens breathing high levels of ozone to getting sunburned. Do it once or twice and you’ll be OK; do it all the time and you could wind up with permanent damage.
That’s not to say you should retreat to the gym forever. “No one in their right mind would say never exercise outdoors,” says Greenbaum. “There are so many physical and mental benefits.” Even small amounts of sunlight boost blood levels of vitamin D (a critical nutrient related to bone strength, immune function, and yes, lung health). Natural terrain challenges your muscles and balance better than any gym machine. And being outdoors is a proven mood booster. One study found that even recalling outdoor exercise can improve your outlook. You just need to be safe about exercising outside.