When we think of breathing polluted air, we often focus on how it affects our lungs, such as by making asthma or other lung conditions worse. But air pollution can also have severe effects on our hearts and blood vessels.
The World Health Organization has estimated that each year, more than 800,000 people die earlier than expected because of breathing fine-particle pollution over a long time.
Now, new results from the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA) show that long-term exposure to air pollution can accelerate the build-up of calcium in the arteries that supply blood to the heart, a process known as coronary artery calcification.
The build-up of calcium and other substances like cholesterol in the arteries causes them to harden and narrow over time. The presence of calcification in a coronary artery indicates that process is advanced. This can lead to heart attack, stroke, and premature death.
Study results were published in the journal The Lancet in May 2016. Dr. David Jacobs is the University of Minnesota co-investigator on the MESA study and co-author on the Lancet paper.
“We have known for some time that air pollution is related to cardiovascular disease, but what happens to cause this has been kind of a puzzle,” Jacobs said.
St. Paul was one of six cities involved in this large, 10-year study of air pollution and cardiovascular disease. The other cities were Baltimore, Chicago, Los Angeles, New York City and Winston-Salem, North Carolina. The study, led by the University of Washington in collaboration with investigators at the University of Minnesota, modeled the amount of air pollution individual people were exposed to over time and followed them with clinical tests, CT scans and ultrasound, to detect signs of coronary artery calcification. Participants recruited from St. Paul experienced some of the lowest levels of air pollution in the study.
According to Jacobs, “This study did something unique by personalizing the exposure measurement.” Investigators combined data from air monitors placed outside the home, indoor monitors, personal backpacks, sources in the home, and data on land use to develop a model for estimating each participant’s individual exposure.
The progression of atherosclerosis in the coronary arteries over time observed in this study helps us understand how long-term exposure to air pollution contributes to heart attacks and deaths. The study authors conclude that there is a need for global action to reduce air pollution for prevention of cardiovascular diseases. “We should think – as we get smarter – how to live our lives with less impact on the environment. It will be healthier for us all,” commented Jacobs.
What you can do:
- Be air aware: Check MPCA’s Air Quality Index before engaging in outdoor activity. Consider adjusting your plans when air quality is in the orange or red range, especially if you have an underlying heart condition.
- Take care of your heart! Visit the American Heart Association to learn about preventing and managing heart disease.
- Learn more: Explore data on air pollution and heart disease in Minnesota on MN Public Health Data Access.