Multi-Ethnic Study of Atherosclerosis and Air Pollution

The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) investigated the relationship between air pollution and the progression of disease in the heart and blood vessels. The MESA Air study advanced our understanding of the impact of air pollutants on cardiovascular disease and provided a research platform for advances in environmental epidemiology. 

Headquartered at the University of Washington and led by principal investigator Dr. Joel Kaufman, the 10-year study was the largest study of its kind. It included 14 research institutions and nearly 7,000 participants from across the United States. Though the main study and a 4-year follow-up (MESA Air Next Stage) have concluded, work continues through collaborations within MESA and with other epidemiological cohorts. The MESA Lung Study continues to investigate the impact of air pollution on respiratory outcomes, and we have applied the approach developed in MESA Air to numerous other cohorts and consortia (e.g., HCHS/SOL, SPIROMICS, ECHO, Sister Study, WHI, NIH-AARP, PRESTO, CHAP, GEMS).   

How did the study work?

Researchers collected air samples from the places where study participants lived. They then estimated air pollution levels using state-of-the-science spatiotemporal air pollution models. The models allowed researchers to estimate air pollution levels at the residential level and see how those levels changed over time and differed within and between regions. At the same time, study participants underwent non-invasive health tests that tracked subtle changes in their heart and blood vessels and were followed up for health events over 25+ years. 

What did the MESA Air study find?

Increased concentrations of air pollution, in ranges commonly encountered worldwide, are associated with a progression in coronary artery calcium. This study provides important new information about the underlying biological processes of long-term exposure to air pollutant concentrations and their association with cardiovascular disease. 

Exposure to higher levels of air pollutants (PM2.5 and NO2) resulted in higher levels of all-cause mortality and incident cardiovascular events.  

Long-term exposure to ambient air pollutants, especially O3, was significantly associated with increasing emphysema assessed quantitatively using CT imaging and with worsening lung function.