Severe heat and cold top list of deadly natural hazards

Before you buy that beautiful ranch house in West Texas, check this map.

Researchers have assembled a comprehensive map showing the number of deaths caused by natural hazards between 1970 and 2004. The map, published online December 16 in the International Journal of Health Geographics, tracks deaths in the United States caused by natural events including severe weather, tornadoes, floods and hurricanes.

Significantly high mortality was identified in the South, which researchers Kevin Borden and Susan Cutter, both of the University of South Carolina in Columbia, attribute largely to severe weather and tornadoes. Other danger zones include parts of the Mississippi Valley and Great Plains. Regions of the Midwest and urban Northeast have significantly lower mortality levels than the rest of the country.

Instead of highly publicized natural disasters such as Hurricane Andrew in 1992 and the 1994 Northridge earthquake, heat is what emerged as the number one killer, accounting for 19.6 percent of all deaths from natural hazards. Severe weather and winter weather caused the next highest numbers of deaths, each making up about 18 percent. Lighting strikes, which the researchers painstakingly separated from deaths caused by other weather-related events, led to 11.3 percent of deaths.

In contrast, the combined percentage of deaths from earthquakes, hurricanes and fires makes up less than five percent of all deaths.

“I think most educated people would assume you see a higher mortality from big events, like earthquakes, hurricanes and floods, because those things are newsworthy,” says Cutter. “But to confirm that it’s everyday, more frequent events that add up to a big loss is a new perspective.”

The study ends at 2004. In 2005, Hurricane Katrina killed 1,294 people and left 595 people missing, according to estimates from The Earth Institute at Columbia University in New York City. Cutter predicts: “If we added four more years of data, including Katrina, the geographic patterns would change a bit.” Cutter says she can’t know how much of an impact Katrina would have on the map of casualties, because the fatalities from that event are still being tallied.