Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Lung Disease & Respiratory Health Center

Font Size

Air Pollution Is Dangerous, but Deadly?

Long-Term Ozone Exposure Boosts Risk for Lung-Related Death, Study Shows
WebMD Health News
Reviewed by Louise Chang, MD

March 11, 2009 -- Long-term exposure to ground-level ozone significantly increases the risk of death from respiratory problems, a new study shows.

A team of scientists says the risk of dying from respiratory problems is more than 30% greater in metropolitan areas with the highest ozone concentrations than areas where ozone levels were the lowest.

Ground-level ozone, along with particulate matter, is a major component of smog. Ozone is a naturally occurring gas most prevalent high in the atmosphere, where it protects against harmful ultraviolet rays of the sun. However, ozone at ground level is produced when exhaust from cars, power plants, and other sources reacts chemically in sunlight. According to the Environmental Protection Agency, ground-level ozone can irritate breathing, decrease lung function, inflame airways, and worsen lung conditions such as asthma and emphysema.

Previous studies have shown that long-term exposure to fine particulate matter -- tiny particles of dust and soot -- are a major risk factor for death from heart and lung disease.

But until now, it was unclear whether ozone was linked to a higher risk of death from lung disease itself, Michael Jerrett, PhD, tells WebMD. Jerrett is an associate professor of environmental health at the University of California-Berkeley and lead author of the study.

Now that’s no longer in question, he says.

“This is the first study to show that ozone, long considered a secondary pollutant, is a key cause of death,” he says. “This is the first time we’ve been able to connect chronic exposure to ozone with the risk of death.”

1 | 2 | 3

Today on WebMD

man coughing
You may not even know you have it.
blood clot
Signs of this potentially fatal complication.
man coughing
When a cold becomes bronchitis.
human lungs
Causes behind painful breathing, fluid buildup.

chest x-ray
Bronchitis Overview
Copd Myth Fact Quiz
Energy Boosting Foods

woman coughing
Lung xray and caduceus