People who live in polluted areas are more likely to die from heart disease and stroke than those who do not, shows a new study from Kaiser Permanente researchers.
“Scientists generally agree that long-term exposure to air pollution can affect the heart and the blood vessels,” said Stacey Alexeeff, PhD, a research scientist at the Kaiser Permanente Northern California Division of Research who led the study. “Our study shows which specific types of cardiovascular disease we should be most concerned about.”
The study was published online in the Journal of the American Heart Association. The researchers looked at 69 previous research studies on air pollution. They found that being exposed to air pollution for long periods — defined as a year or more — increased the risk of death from coronary heart disease by 23% and from stroke by 24%. They also found that long-term exposure to air pollutants increased the risk of a person’s first stroke by 13% and of a first heart attack by 8%.
“This study reinforces the need to direct policy efforts to improve air quality in order to reduce the societal burden of heart disease, stroke, and the 108,000 deaths in the U.S. each year that are directly attributable to air pollution,” said the study’s senior author Stephen Sidney, MD, MPH, a research scientist at the Division of Research.
Previous studies showed that levels of small particle air pollution are higher in Black, Latinx, and low socioeconomic neighborhoods. “This is primarily because these groups are more likely to live in high-traffic areas or close to factories, power plants, and refineries that release high levels of this type of pollution,” said Dr. Sidney. “This structural racism must be addressed to reduce risk for cardiovascular disease in these communities.”
The study focused on the effects of fine particulate matter (PM2.5) pollutants which are about 30 times smaller than the width of a piece of hair. These minute particles are released in exhaust from cars, trucks, and other vehicles; from burning wood, heating oil, and coal; and by factories, power plants, and forest fires.
Pollution causes problems for the body’s cells and tissues, including a type of chronic inflammation that leads to plaque buildup in the arteries. If a piece of this plaque breaks off, it can cause a blood clot that blocks an artery to the heart or brain, cutting off blood flow and resulting in a heart attack or stroke.
When talking about long-term exposure to pollution, said Alexeeff, “what we are really talking about is where people live. People can’t just move to a cleaner area. The level of increased risk we found means that long-term air pollution exposure is an important modifiable risk factor for cardiovascular disease that needs to be taken seriously.”