Do Face Masks Protect against Air Pollution-Related Health Problems?

Many people around the world, especially in Asia, wear face masks to protect against air pollution. Do they work?

Sanjay Rajagopalan, MD, Herman Hellerstein, professor of cardiovascular medicine at Case Western Reserve University School of Medicine and chief of cardiovascular medicine at University Hospitals Cleveland Medical Center, has received a $2 million National Institutes of Health grant to help find out if face masks really protect against air pollution.

Rajagopalan will serve as the principal investigator (PI) for a team of Case Western Reserve University School of Medicine and University Hospitals colleagues, as well as researchers from Peking University, the University of Kentucky, and the University of Michigan, in an international study – ASPIRE (Air Pollution: Strategies for Personalized Intervention to Reduce Air Pollution Exposure) – of the effects of air pollution on the cardiovascular system.

In the study, the researchers will evaluate the ability of the devices to reduce exposure to an air pollutant known as fine particulate matter. This pollutant takes the form of minute particles in the air, making it look hazy and reducing visibility. Breathing it in increases the risk of heart disease, stroke, cancer, asthma, and other respiratory problems.

According to a new study published in the Lancet, approximately 4.2 million deaths in 2015 were attributed to air pollution, a twenty percent increase from 1990. Last year, researchers from the Health Effects Institute in Boston reported that on some days in Beijing or Delhi, the number of fine particles in the air can be ten times what is considered a safe level.

The global air pollution picture is a story of contrasts. While the air in many North American and European cities is far from pure, their problems are dwarfed by the statistics in Asia where levels of air pollution and the complications that arise from the constant exposure are having dire consequences.

“Air pollution puts millions of people, throughout the world, even here in North America, at risk of serious health problems,” said Rajagopalan. “While the eventual solution to air pollution must be rigorous regulation, sufficient improvements in air quality are not going to happen anytime soon. Our new study will examine whether face masks known as N95 respirators offer effective protection in the meantime.”

The respirators, unlike looser-fitting general surgical masks, are designed to achieve a very close facial fit. The “N95” designation means that the respirator blocks at least 95 percent of very small test particles.

Because air pollution levels in the United States and Europe are now generally too low to adequately evaluate the benefits of interventions such as N95 respirators, especially in smaller populations, the researchers will study heart attack patients in China, where pollution levels are high and expected to remain so for decades. The study will serve as the prelude to a larger definitive trial study in China, India, and Brazil that will examine the effect of this intervention in patients with acute coronary syndrome.

“The results from our study could be broadly applicable to millions of people who are routinely exposed to high levels of air pollution, as well as to visitors to high-pollution locales,” said Rajagopalan.


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About University Hospitals / Cleveland, Ohio
Founded in 1866, University Hospitals serves the needs of patients through an integrated network of 18 hospitals, more than 40 outpatient health centers and 200 physician offices in 15 counties throughout northern Ohio. The system’s flagship academic medical center, University Hospitals Cleveland Medical Center, located on a 35-acre campus in Cleveland’s University Circle, is affiliated with Case Western Reserve University School of Medicine. The main campus also includes University Hospitals Rainbow Babies & Children's Hospital, ranked among the top children’s hospitals in the nation; University Hospitals MacDonald Women's Hospital, Ohio's only hospital for women; and University Hospitals Seidman Cancer Center, part of the NCI-designated Case Comprehensive Cancer Center. UH is home to some of the most prestigious clinical and research programs in the nation, including cancer, pediatrics, women's health, orthopedics, radiology, neuroscience, cardiology and cardiovascular surgery, digestive health, transplantation and urology. UH Cleveland Medical Center is perennially among the highest performers in national ranking surveys, including “America’s Best Hospitals” from U.S. News & World Report. UH is also home to Harrington Discovery Institute at University Hospitals – part of The Harrington Project for Discovery & Development. UH is one of the largest employers in Northeast Ohio with 27,000 employees. For more information, go

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