Death Rates Declining Across U.S., Even As Summer Temperatures
Rise, Study Says
July 29, 2003--
Heat is the primary cause of weather-related death in the
United States. The elderly, young children and people with respiratory
and circulatory problems are particularly vulnerable.
in recent decades the number of heat-related deaths has declined
according to a new University of Virginia study published
on-line in the journal Environmental Health Perspectives. (http://ehpnet1.niehs.nih.gov/docs/2003/6336/abstract.html)
the period studied, 1964-1998, average summer temperatures
and humidity have steadily increased. Most climatologists attribute
to a global warming trend, possibly caused by industrial society’s
increasing use of fossil fuels, which produce carbon dioxide, a “greenhouse” gas.
Many scientists have predicted that heat-related deaths will increase as
why are less people dying from heat stress even as temperatures
The very technologies that may be altering the climate are also making
life better for humans.
declining mortality rate can be attributed to various adaptations,” said
Robert Davis, associate professor of environmental sciences at U.Va.
and the study’s principal investigator. “Air conditioning,
improved medical care, better public awareness programs relating
to potential dangers of heat
stress and both human biophysical and infrastructural adaptations are
and his colleagues calculated heat-related mortality rates for
28 U.S. cities from 1964 to 1998 on days
each year with high temperature
They found an average of 41 heat-related deaths per million people
per year during the 1960s through ‘70s, and clear indications of significantly
higher mortality on high heat and humidity days. But the numbers steadily
declined with each decade.
By the 1990s, there were only an average of 10.5 deaths per million.
decline occurred despite increasingly stressful weather conditions
in many urban and suburban areas,” Davis said.
cities, particularly in the hot and humid southeastern U.S.,
no excess mortality during the 1980s, possibly because
are more acclimated to high temperatures. In the 1990s, the effect
“In general, over the past 35 years, the U.S. populace has become systematically
less impacted by hot and humid weather conditions,” Davis said. “This
research suggests that summer heat-related mortality should continue to decline
despite increasing temperatures.”
Robert Davis, (O) (434) 924-0579, (H) 823-1365