...aggravate respiratory conditions

Pharmaxis is researching respiratory diseases.
Some may be interested in the attached article.

CHICAGO, Nov 16 (AFP) - More than just an irritant that can aggravate respiratory conditions, ground-level ozone may contribute to thousands of deaths every year, a study released Tuesday said.

US researchers investigated the effect of short-term exposure to ozone on death rates in 95 US cities and towns in 14 years, from 1987-2000.

Not only did ozone pollution represent "a substantial health burden," but that even a small increase in ground-level ozone was associated with a slightly higher death rate.

The daily average for ozone nationwide is about 40 parts per billion, but the level can be dramatically higher in summer, especially in urban centers, according to the paper in the Journal of the American Medical Association (news - web sites).

When ozone levels rose by 10 parts per billion during a given week, people were about half a percent more likely to die, the researchers said.

That would correspond to about 3,800 additional deaths nationally each year in the 95 urban centers from Honolulu to New York covered by the study, they said.

The ozone-death link has been made in a few previous studies, but the new research is the most comprehensive of its kind, said Jonathan Levy, an assistant professor at the Harvard School of Public Health who was not involved with the new study.

"Something that contributes to 4,000 premature deaths annually is something to pay attention to," Levy said.

The authors could not say for sure why this form of ozone, the key ingredient in smog, appears to kill people, though they noted that inflammation has been theorized as playing a key role.

The increasing prevalence of ozone in urban centers across the United States and other countries has been linked to increasing vehicle emissions.

The study was conducted by researchers at the Yale School of Forestry and Environmental Studies, and the Johns Hopkins Bloomberg School of Public Health.

http://story.news.yahoo.com/news?tmpl=story&cid=1507&e=5&u=/afp/20041117/hl_afp/us_health_ozone_041117022907