Long-term exposure to air pollution was linked to increases in emphysema between 2000 and 2018, according to a new study funded by the National Institute of Environmental Health Sciences (NIEHS) and the National Heart, Lung, and Blood Institute (NHLBI), both part of the National Institutes of Health. The study is published in The Journal of the American Medical Association.
“These findings may offer one explanation for why emphysema is found in some people who never smoked,” says 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 relationship between various air pollutants and emphysema was measured through CT lung imaging and lung function testing. Consistent results were found in these varied metropolitan regions: Winston-Salem, N.C.; St. Paul, Minn.; New York City; Baltimore; Chicago; and Los Angeles. Participants came from the Multi-Ethnic Study of Atherosclerosis (MESA), a medical research study, and involved more than 7,000 men and women from the six localities.
“The combined health effect of multiple air pollutants ? ozone, fine particles known as PM2.5, nitrogen oxides, and black carbon ? was greater than when the pollutants were assessed individually,” says Bonnie Joubert, PhD, a scientific program director at NIEHS. “With the study’s long-running duration, repeated CT scans allowed analysis of changes in emphysema over time.”
Researchers measured all major air pollutants with longitudinal increases in percent emphysema revealed by more than 15,000 CT scans acquired from 2000 to 2018. Over the same period, MESA carefully tracked air pollution. MESA is unique in its meticulous characterization of air pollution exposures along with repeated CT scans of lungs in study participants.
“We need to assess the effectiveness of strategies to control air pollutants in our efforts to improve heart and lung health,” says David Goff, MD, PhD, 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 smoking cessation for overall health.”
