Hotter temperatures mean more ozone, and more strain on hearts, researchers say
WEDNESDAY, Nov. 21 (HealthDay News) -- Soaring temperatures and high ozone levels work together to boost death risks from heart disease and stroke, researchers report.
They believe that global warming -- which brings more heat and more ozone -- may further increase the number of people who die of cardiovascular events.
"Temperature and ozone are strong factors in cardiovascular mortality during June to September in the Unites States," noted the study's lead author, Cizao Ren, from the Department of Epidemiology in the School of Medicine at the University of California, Irvine. "Temperature and air pollution combine to affect the health of large populations," he added.
Ren expects the problem will get worse as the earth becomes hotter. "Increases in temperature and air pollution will have a strong affect on health," he said.
His team based its findings on data on almost 100 million people living in 95 different areas across the United States from June to September.
These Americans were included in the National Mortality and Air Pollution Study, which tracked links between health and air pollution for the years 1987 to 2000.
Four million deaths from heart attacks or strokes occurred during the study period. Ren's team compared death rates against changes in temperature during one day.
Ozone was a common link, they found.
In fact, the higher the ozone level, the greater the risk of cardiovascular death attributable to high temperatures, Ren's team concluded.
Ozone levels ranged from an average of 36.74 parts per billion to 142.85 parts per billion, while daily temperatures ranged from 68 to around 107 degrees Fahrenheit.
When the ozone level was at its lowest, a 10-degree increase in temperature was associated with about a 1 percent increase in deaths from heart disease
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