Higher ozone levels linked to heart death

BRISBANE, Australia, Nov. 23 (UPI) -- An Australian study of U.S. data showed that the higher the ozone level, the higher was the risk of cardiovascular death attributable to high temperatures.

Australian researchers used data from the National Mortality and Air Pollution Study, which looked at health and weather pollution in the United States from 1987 to 2000 during which 4 million heart attacks or strokes occurred.

The researchers plotted daily deaths against fluctuations in temperature during one day, they found that ozone was a common link.

The study, published in Occupational and Environmental Medicine, found a 10 degree temperature increase on the same day was associated with a rise in heart disease or stroke deaths of just over 1 percent at the lowest ozone level and by more than 8 percent for the highest levels.

Ozone is chemical pollutant generated by a reaction between nitrogen oxides, volatile organic compounds and oxygen in the presence of sunlight.