Air Pollution Is Dangerous, but Deadly?
Long-Term Ozone Exposure Boosts Risk for Lung-Related Death, Study Shows
WebMD News Archive
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
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.”