News / Health

Air Pollution Linked to Artery Hardening, Increased Stroke Risk

Jessica Berman
U.S. researchers say urban dwellers exposed to the highest levels of fine particulate air pollution had faster hardening of the arteries, putting them at increased risk of stroke, compared to people in less polluted sections of the same city.  The finding adds to a growing body of evidence that residing in polluted urban areas is a risk factor for cardiovascular disease.

Atherosclerosis, or hardening of the arteries, is a leading cause of death around the world.  It can cause stroke or death when a blood clot or piece of hardened plaque inside a blocked coronary artery breaks off and travels to the brain, cutting off blood flow.

To investigate the role of air pollution in the development of atherosclerosis, researchers followed a group of almost 5,400 adults in six metropolitan areas.  None of the participants was known to have heart disease.  They were part of a larger U.S. study called the Multi-Ethnic Study of Atherosclerosis and Air Pollution, or MESA Air.

Between 2000 and 2005, researchers conducted two non-invasive ultrasound examinations on each participant, at intervals of three years, to measure the thickness of the subjects' carotid artery walls.  The carotid carries blood to the head, neck and brain.  Thickening of an arterial wall is a good indicator of atherosclerosis throughout the body, even in patients with no obvious symptoms of heart disease.

Analyzing the ultrasound results, researchers found a slight, but significant increase in the thickening of carotid artery walls among individuals who resided in high pollution areas compared to those in less polluted urban centers.  According to lead researcher Sara Adar, an epidemiologist at the University of Michigan School of Public Health, their findings corroborated earlier studies of the group.

“Based on another study that was done in the same cohort [group] of people, they found that the amount of change that we saw for living in a high-pollution neighborhood versus living in a low pollution neighborhood would correspond to about a  two percent increased risk of stroke," said Adar.

Fine particulate air pollution, the kind of black soot belched out by smoke stacks and the tailpipes of buses in many urban areas around the world, is widely believed to cause inflammation and oxidative stress that can contribute to heart disease.

Adar says people already are encouraged to stay indoors on days when pollution is particularly high.  But she says doctors should make a point of discussing the hazards of air pollution with their patients:

“So, just as they might ask somebody 'Do you smoke?' or think about if someone is obese,  [the question of] how long someone has lived in a highly polluted environment might factor into a physician’s notion of whether or not somebody is at high or low risk for cardiovascular disease or heart disease," she said.

An article linking air pollution to accelerated hardening of the arteries is published in the journal PLoS Medicine.  

You May Like

800-Pound Man Determined to Slim Down

Man says he was kicked out of hospital for ordering pizza; wants to be an actor More

Australia Prepares to Resettle 12,000 Syrian Refugees

Preference will be given to refugees from persecuted minorities, and the first group is expected to arrive before late December More

S. African Miners Seek Class Action Suit Against Gold Mines

The estimated 100,000 say say they contracted the lung diseases silicosis and tuberculosis in the mines More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Amnesty Accuses Saudi Coalition of ‘War Crimes’ in Yemeni
Henry Ridgwell
October 12, 2015 4:03 PM
The human rights group Amnesty International has accused the Saudi-led coalition of war crimes in airstrikes against Houthi rebels in Yemen. Henry Ridgwell reports the group says hundreds of civilians have been killed in strikes on residential areas.

Video Amnesty Accuses Saudi Coalition of ‘War Crimes’ in Yemen

The human rights group Amnesty International has accused the Saudi-led coalition of war crimes in airstrikes against Houthi rebels in Yemen. Henry Ridgwell reports the group says hundreds of civilians have been killed in strikes on residential areas.

Video No Resolution in Sight to US House Speaker Drama

Uncertainty grips the U.S. Congress, where no consensus replacement has emerged to succeed Republican House Speaker John Boehner after his surprise resignation announcement. Half of Congress is effectively leaderless weeks before America risks defaulting on its national debt and enduring another partial government shutdown.

Video New Art Exhibit Focuses on Hope

Out of struggle and despair often comes hope. That idea is behind a new art exhibit at the American Visionary Art Museum in Baltimore, Maryland. "The Big Hope Show" features 25 artists, some of whom overcame trauma and loss. VOA’s Deborah Block reports.

Video Columbus Day Still Generates Controversy as US Holiday

The second Monday of October is Columbus Day in the United States, honoring explorer Christopher Columbus and his discovery of the Americas. The achievement is a source of pride for many, but for some the holiday is marked by controversy. Adrianna Zhang has more.

Video Anger Simmers as Turks Begin to Bury Blast Victims

The Turkish army carried out new air strikes on Kurdistan Workers Party (PKK) targets on Sunday, a day after the banned group announced a unilateral cease fire. The air raids apparently are in retaliation for the Saturday bombing in Turkey's capital Ankara that killed at least 95 people and wounded more than 200 others. But as Zlatica Hoke reports, there are suspicions that Islamic State is involved.

Video Bombings a Sign of Turkey’s Deep Troubles

Turkey has begun a three-day period of mourning following Saturday’s bomb attacks in the capital, Ankara, that killed nearly 100 people. With contentious parliamentary elections three weeks away, the attacks highlight the challenges Turkey is facing as it struggles with ethnic friction, an ongoing migrant crisis, and growing tensions with Russia. VOA Europe correspondent Luis Ramirez reports.

Video Afghanistan’s Progress Aided by US Academic Center

Recent combat in Afghanistan has shifted world attention back to the central Asian nation’s continuing civil war and economic challenges. But, while there are many vexing problems facing Afghanistan’s government and people, a group of academics in Omaha, Nebraska has kept a strong faith in the nation’s future through programs to improve education. VOA’s Greg Flakus has more from Omaha, Nebraska.

Video House Republicans in Chaos as Speaker Favorite Withdraws

The Republican widely expected to become the next speaker of the House of Representatives shocked his colleagues Thursday by announcing he was withdrawing his candidacy. The decision by Majority Leader Kevin McCarthy means the race to succeed retiring Speaker John Boehner is now wide open. VOA National Correspondent Jim Malone reports.

Video German, US Officials Investigate Volkswagen

German officials have taken steps to restore some of the reputation their car industry has lost after a recent Volkswagen diesel emissions scandal. Authorities have searched Volkswagen headquarters and other locations in an effort to identify the culprits in the creation of software that helps cheat on emission tests. Meanwhile, a group of lawmakers in Washington held a hearing to get to the bottom of the cheating strategy that was first discovered in the United States. Zlatica Hoke reports.

Video Why Are Gun Laws So Hard for Congress to Tackle?

Since taking office, President Barack Obama has spoken out or issued statements about 15 mass shootings. The most recent shooting, in which 10 people were killed at a community college, sparked outrage over the nation's gun laws. But changing those laws isn't as easy as many think. VOA's Carolyn Presutti reports.

Video In 'He Named Me Malala,' Guggenheim Finds Normal in Extraordinary

Davis Guggenheim’s documentary "He Named Me Malala" offers a probing look into the life of 18-year-old Malala Yousafsai, the Pakistani teenager who, in 2012, was shot in the head by the Taliban for standing up for her right to education in her hometown in Pakistan's Swat Valley. Guggenheim shows how, since then, Malala has become a symbol not as a victim of brutal violence, but as an advocate for girls’ education throughout the world. VOA’s Penelope Poulou has more.

Video Paintable Solar Cells May Someday Replace Silicon-Based Panels

Solar panels today are still factory-manufactured, with the use of some highly toxic substances such as cadmium chloride. But a researcher at St. Mary’s College, Maryland, says we are close to being able to create solar panels by painting them on a suitable surface, using nontoxic solutions. VOA’s George Putic reports.

VOA Blogs