Nov. 15, 2004 -- Winter brings a break from ozone-related deaths, according
Nov. 15, 2004 -- Winter brings a break from ozone-related deaths, according to a new European study.
Ozone is a bluish toxic gas in the earth's stratosphere. It irritates lung tissue, causes inflammation, and is considered to be one of the most harmful compounds in air pollution.
The new study collected the environmental daily ozone concentration and tracked the daily number of deaths in 22 European cities and Tel Aviv, Israel, for at least three years since 1990.
The study used the maximum daily one- and eight-hour ozone concentration to represent daily ozone concentrations.
Data showed an increase in deaths during warm months, when ozone levels were higher. However, daily ozone concentrations didn't affect mortality during winter in any of the cities.
After gathering all the data on the cities studied, they show that during the warm season an increase in the one-hour ozone concentration of 10 units was associated with a 0.33% increase in daily death rates. That increase in ozone concentration was associated with significant increases of 0.45% in daily cardiovascular deaths and a 1.13% in daily respiratory deaths.
Klea Katsouyanni, MSc, DMedSc, of the University of Athens Medical School, and colleagues report the findings in the Nov. 15 issue of the American Journal of Respiratory and Critical Care Medicine.
Ozone's impact on mortality was strongest in the study's southern cities, which have larger concentrations of ozone, write the researchers.
Daily ozone concentrations had a greater effect on deaths from respiratory problems than on deaths from heart disease.
It's not known if residents of any of the cities were taking antioxidant vitamins, which may fight ozone's effects.
Ozone is also a problem in the U.S. According to the American Lung Association's 2004 State of the Air report; 55% of Americans live in counties with unhealthy levels of either ozone or particle pollution.
