Did Pandemic Lockdowns Lead to Fewer Heart Attacks? - Everyday Health
Could there actually be a silver lining to the pandemic? New research draws a connection between less air pollution in the United States during the shutdowns and stay-at-home orders of COVID-19 to fewer heart attacks.
The study abstract was presented at the American Heart Association’s Scientific Sessions 2021, which was held virtually November 13–15.
“Reducing pollution is not only helpful for the environment, it may also have significant health benefits at the population level, such as preventing heart attacks,” said the study's lead author, Sidney Aung, a fourth-year medical student at the University of California in San Francisco, in an AHA statement.
Pollution Causes Millions of Early Deaths Each Year
Worldwide, it’s estimated that pollution caused nine million deaths in 2019, according to the Global Burden of Disease (GBD) study, and an estimated three in five of those deaths were due to cardiovascular disease, including heart attack and stroke.
Heart disease is the number one cause of death in the United States, according to the Centers for Disease Control and Prevention (CDC). It’s estimated that about 659,000 deaths — one out of every four — is due to heart disease.
For Many Americans, the Pandemic Put the Brakes on Driving
The pandemic led to a “drastic” drop in U.S. road travel and a sharp increase in the number of people who chose to stay home all day, according to research from the travel service AAA.
Daily trips for all modes of transportation dropped from an average of 3.7 trips per day in 2019 to 2.2 trips in April 2020, when much of the country was under stay-at-home orders. Daily trips rebounded slightly, but still remained 20–25 percent below 2019 levels during the second part of 2020, according to the report.
Analysis Linked Lower Pollution Measurements to a Reduction in Heart Events
Researchers analyzed pollution and heart attacks that occurred between January 1, 2019, and April 30, 2020. Pollution measurements were taken from the U.S. Environmental Protection Agency’s website, focusing on a common type of air pollution called particulate matter 2.5, which contains microscopic solids.
Heart attack frequency was assessed in various U.S. regions using records from the National Emergency Medical Services Information System and the U.S. Census.
A total of 60,722 heart attacks occurred during the study. With each 10 micrograms per cubic meter drop in particulate matter 2.5, the number of heart attacks decreased by 6 percent, which translated to 374 fewer heart attacks per 10,000 person-years.
“This is a very interesting finding, and I find it credible,” says Philip Landrigan, MD, a professor and the director of the Global Public Health Program at Boston College. Dr. Landrigan coauthored a paper published in November in the New England Journal of Medicine highlighting the need for healthcare providers to begin screening for and treating air pollution exposure.
“It certainly aligns with the vast body of scientific information that’s been produced in the past two decades on the impacts of air pollution on the heart,” says Landrigan, referring to a number of studies and meta-analyses published that link particulate matter levels (a measure of the amount of tiny pieces of matter such as dust or smoke) to heart disease and risk of heart attack and stroke, as well as cardiovascular risk factors such as hypertension and diabetes.
Although this study is observational and therefore can’t prove cause and effect, Landrigan points out that conclusively proving that air pollution causes heart attacks through a randomized controlled study wouldn’t be possible. “There’s no way in the world — either practically or ethically — that we could take two groups of people and expose one to air pollution and not expose the other,” he says.
These findings on declining rates of air pollution and declining rates of heart attack are totally consistent with other research that has shown that high amounts of air pollution lead to greater numbers of deaths from heart attack, says Landrigan. “Exposure to air pollution needs to be added to the list of risk factors for heart disease and stroke,” he adds.
Tips on Doing Your Part to Reduce Air Pollution
The reopening of schools and offices means that staying home all day isn’t an option for many of us, but there are still changes you can make in your daily life that can make a difference. The United States Environmental Protection Agency (EPA) suggests the following strategies to reduce the level of air pollution from vehicles:
- Save gas by carpooling, using public transportation, biking or walking whenever possible.
- Keep your car engine properly tuned and make sure your tires are properly inflated.
- Choose fuel efficient, hybrid, or fully electric vehicles.
- Don’t idle.