Breathing dirty city air is as bad for your lungs as smoking

Even if you’ve never smoked, just living in a city with polluted air could lead to emphysema. A new study published in the Journal of the American Medical Association found that air pollution—and in particular ozone, which is increasing with climate change—makes the lung disease progress faster. If you live in a city with high ozone levels for a decade, the results are similar to smoking a pack of cigarettes daily for three decades.

Some past research has found that short spikes in air pollution can worsen lung disease in people who are already sick, and other research has linked air pollution to asthma in children. But this study was the first to look in detail at the long-term effects of air pollution on lung health in adults. “Chronic obstructive lung diseases like emphysema are collectively now one of the leading causes of mortality and morbidity among older adults,” says Joel Kaufman, professor of environmental and occupational health sciences and epidemiology in the University of Washington’s School of Public Health. “And the relationship between air pollution and the development of those conditions is not well understood.” More than a quarter of people who have emphysema were never smokers.

The researchers studied more than 7,000 people over 18 years in six metropolitan areas, including particularly smoggy cities like New York City and Los Angeles, looking at local air pollution levels and CT scans of the lungs of the participants. Different types of pollution—particulate matter, black carbon, nitrogen oxide, and ambient ozone—were all associated with increasing levels of emphysema in the lungs. But the link with ambient ozone was especially strong.