Severe Drought Conditions Linked to Increase Risk of Death

A new study led by Yale University's School of Forestry and Environmental Studies (FE&S) revealed that droughts could negatively impact the health of older adults, increasing their risk of mortality.

The study, published in the journal The Lancet Planetary Health, showed that worsening or severe drought conditions can increase the risk of cardiovascular disease, respiratory disease and even death.

"There's a lot of research on how different kinds of environmental disasters -- such as forest fires, hurricanes, air pollution, or heat waves -- impact human health, but the most widespread natural disaster is drought," said lead author Jesse Berman, a postdoctoral fellow at the Yale FE&S, in a press release. "And yet there's been limited research looking at the health impacts of drought -- particularly here in the U.S."

For the study, the researchers identified periods of "non-drought", "full drought" and "worsening drought" using the U.S. Drought Monitor Data compiled across 22 western states from 2000 to 2013. They also calculated the daily rate of respiratory admissions, cardiovascular admissions and deaths among people 65 years old and older using Medicare claims.

The researchers found that hospital admissions due respiratory problems were down by 1.99 percent during dull drought periods. They also observed a 1.55 percent increase in mortality rate when drought escalated to "high severity worsening" conditions.

Furthermore, the researchers found that people living in counties that rarely experience drought had an increased risk of mortality and cardiovascular diseases during worsening drought conditions.

It is still unclear how drought triggers a negative health outcome. The researchers believe that it is possible for drought to create some changes in growing seasons or have some kind of influence on allergens responsible for some respiratory diseases. Dry conditions due to drought could also trigger more dust and particulate matter in the air.

Drought can be considered as slow moving when compared to other severe weather events. Due to this, there is some time to enact clinical interventions to avoid drought-induced health outcome.