We now know how air pollution increases risk for heart disease, thanks to a 10-year study linking poor air quality to accelerated calcium build-up in the heart’s arteries.
Published in The Lancet, this study looked at the long-term effects of air pollution on the heart’s arteries. It’s well established that air pollution increases risk for heart disease—the No. 1 killer of men and women in the United States. Tiny particles in the air called fine particulate matter can go deep into the lungs and cause serious health problems, such as heart disease and certain types of cancer. But little is known about how air pollution interacts with the body and increases risk for heart disease—until now.
Funded by the United States Environmental Protection Agency, the MESA Air study (Multi-Ethnic Study of Atherosclerosis and Air Pollution) was a 10-year project that explored the relationship between air pollution and the progression of heart disease. The study followed nearly 6,800 healthy adults from 2002–2012, closely tracking their health and exposure to air pollutants. Participants were from six U.S. metropolitan areas, where air pollution tends to be greatest.
During the study, participants underwent ultrasounds to measure the thickness of their carotid arteries, which deliver blood to the brain. Participants also had repeated CT scans to measure calcium build-up in the arteries, called coronary artery calcium. Coronary artery calcium (or CAC) is an early sign of heart disease and can increase risk for heart events, even with no symptoms.
As expected, both coronary calcium and arterial thickness steadily increased in participants over the 10-year period. However, participants with more exposure to air pollution had significantly greater calcium build-up than those without. The more air pollution participants were exposed to, the more quickly calcium build-up progressed. Thickening of the arteries, on the other hand, was not related to exposure to air pollution over the 10-year study.
According to authors, this study highlights the need to reduce air pollution to help combat heart disease. Heart disease is the leading killer of Americans, accounting for 1 in 4 deaths each year. It’s clear that air pollution has a direct negative impact on heart health, speeding up calcification of the arteries and increasing risk for heart disease. As a result, authors argue that reducing air pollution may be a useful strategy for reducing cardiovascular risk. Through policy change and other efforts to improve air quality, experts hope to reduce air pollution and promote better heart health.