Ozone Pollution Taking Toll on American Lives

Mar. 12 -- WEDNESDAY, March 11 (HealthDay News) -- Thousands of Americans are dying each year from lung disease caused by atmospheric ozone, a new study finds.

The greatest risk may for those living be in hot, dry cities such as Los Angeles, which has one of the highest concentrations of ozone. Residents of Los Angeles may face a 25 percent to 30 percent higher annual risk of dying from a respiratory ailment versus people in low-ozone areas such as the Great Plains, the researchers said.

The report, published in the March 12 issue of the New England Journal of Medicine, also found that that tiny components of smog called "fine particulate matter" had a clear link to cardiovascular deaths.

"This is one of the first studies where we've been able to report separate independent effect from both particulate matter and ozone," said lead researcher Michael Jerrett, an associate professor of environmental health sciences at the School of Public Health, University of California, Berkeley. "With particulate matter, we see effects very strongly for cardiovascular mortality such as heart attack and stroke and, for ozone, we see them in respiratory deaths."

"That suggests that we can't just regulate particulate matter or ozone," Jerrett continued. "We have to look at dealing with both pollutants because they're both exerting major impacts, but on different mortality outcomes."

An estimated 240,000 people in the United States and 7.7 million people worldwide die of respiratory disease each year, according to data from the World Health Organization.

Efforts to reduce ground-level ozone have stalled in recent years, Jarrett said, and now one in three Americans lives in an area that exceeds the national standard for ozone levels.

A year ago, the U.S. Environmental Protection Agency did issue stricter air quality standards for ground-level ozone, but many scientists advocate still lower levels.

When hovering seven miles above the earth, ozone is actually beneficial because it blocks ultraviolet radiation from the sun. However, closer to the ground it infiltrates the lungs and may cause damage. A number of studies have tried to link ozone exposure with mortality but they have been inconclusive, the researchers noted.