Study finds link between long-term exposure to air pollution and emphysema

A new study found that long-term exposure to air pollution is strongly linked to emphysema, a deadly lung disease often associated with smoking.

“These findings may offer one explanation for why emphysema is found in some people who never smoked,” said James Kiley, Ph.D., NHLBI’s director of the Division of Lung Diseases. “The study’s results, duration, and timing offer insight into the long-term effects of air pollution on the U.S. population.”

The study examined the relationship between several major air pollutants and emphysema as measure through computed tomography (CT) lung imaging and lung function testing. The pollutants studied included ozone, fine particulate matter, oxides of nitrogen, and black carbon. The 18-year study involved more than 7,000 people in six metropolitan regions across the United States: New York; Los Angeles; Chicago; Baltimore; Winston-Salem, North Carolina; and St. Paul, Minnesota. The participants were drawn from the Multi-Ethnic Study of Atherosclerosis (MESA) Air and Lung studies.

The researchers found that air pollution was associated with a higher level of emphysema progression in the study population based on CT scans. They also found that ozone exposure, but not the other pollutants, was associated with a decline in lung function. The researchers said that long-term exposure to air pollution could cause as much lung damage over time as smoking a pack of cigarettes a day.

“It’s important that we continue to explore factors that contribute to emphysema, particularly in a large, multi-ethnic group of adults such as those represented by MESA,” said Kiley, who was not a part of the study.

“We need to assess the effectiveness of strategies to control air pollutants in our efforts to improve heart and lung health,” said David Goff, M.D., Ph.D., director of NHLBI’s Division of Cardiovascular Sciences. “At the same time, people need to remember the importance of a healthy diet, physical activity, and tobacco smoking cessation for overall health.”

This study, which appeared in JAMA,  included support from the U.S. Environmental Protection Agency, the National Institute of Environmental Health Sciences, and the NHLBI.