Air Pollution Is Dangerous, but Deadly?
Long-Term Ozone Exposure Boosts Risk for Lung-Related Death, Study Shows
Ozone vs. Fine Particulate Pollution
The study, published in the March 12 issue of The New England Journal of Medicine, followed 450,000 people from 1982 to 2000 and covered 96 metropolitan regions. Over the 18-year study period, 118,777 people died.
“The study presents evidence for the first time that long-term exposure to ozone and fine-particulate pollution have separate, independent effects on mortality, and that they seem to impact different parts of the body,” Jerrett tells WebMD.
The study also makes clear that controlling ozone would not only reduce deaths, but mitigate global warming, Jerrett says.
George D. Thurston, ScD, a professor of environmental medicine at New York University School of Medicine and a study co-author, says ozone tends to form in higher concentrations in suburbs and rural areas downwind of cities.
That’s due in part to commuting patterns, Jerrett says. It’s hard to keep counts down when governments at all levels can’t control sprawl and “one-person-per-car-commuting,” he says.
Cities With the Highest Ozone Levels
The risk of dying from respiratory causes rises up to 4% for every 10 parts-per-billion increase in exposure to ozone, the study says. Jerrett tells WebMD that over the 18-year study period, Riverside, Calif., had the highest daily average maximum concentration at 104 parts per billion, which “corresponded to a 50% increased risk of dying from lung disease compared to no exposure” to ozone.
He adds that in general, cities in the Northeast had lower ozone than California. New York had a 25% increased risk of lung-related death and Washington, D.C., came in at 27%, compared to 43% in Los Angeles.
The lowest ozone concentrations were recorded in San Francisco.
Charlotte-Gastonia, N.C., Chattanooga, Tenn., Raleigh, N.C., and Richmond, Va., were among the most ozone-rich areas in the South.
Limiting Exposure to Ozone Air Pollution
A clear message to the public, Jerrett says, is that exercise during the sunniest time of the day should be avoided by people who live in warm climates. He also says it’s smart to keep windows closed when ozone levels are highest, and it’s just not good to spend more time outside than indoors when levels of the gas are high.