Health scare of the week: City air can kill

last updated 8 January 2015

Spending just a few hours breathing the air of a typical city is enough to raise your risk of heart attack and stroke, new research shows. Researchers analyzed a decade’s worth of data and found that Boston residents were 34 percent more likely to have a stroke following a day of “moderate” as opposed to “good” air quality—though both levels meet standards of the Environmental Protection Agency. A similar study by French researchers also found that mere hours of exposure to air pollution significantly increases the risk of heart attack. Inhaling fine particles from car exhaust, power plants, and other sources can damage the heart and lungs in much the same way that cigarette smoke does: clogging arteries, increasing inflammation, and raising heart rate and blood pressure. The difference is that “everyone is exposed” to air pollution, Hazrije Mustafic, a French cardiologist, tells Time.com. Both studies point to a need for stricter air-quality standards worldwide, says Johns Hopkins School of Public Health professor Roger Peng. “There is no safe level” of air pollution, he says.