Flooding’s Hidden Killers Include Heart Attacks and Infections

A new study found that flood deaths can rise by 25 percent three months after a disaster

People walk down a street covered in mud and water to inspect the flood damage in the Biltmore Village in the aftermath of Hurricane Helene on September 28, 2024 in Asheville, North Carolina — People inspect the flood damage in the Biltmore Village in the aftermath of Hurricane Helene on September 28, 2024 in Asheville, North Carolina. Hurricane Helene made landfall Thursday night in Florida's Big Bend with winds up to 140 mph.

Sean Rayford/Getty Images

Join Our Community of Science Lovers!

CLIMATEWIRE | Floods could be deadlier than previously thought — and from more than just drowning.

A study published Tuesday in Nature found that the number of U.S. deaths in flooded areas continued to rise for up to three months after the disaster, resulting in a 25 percent higher death rate from things like infections, injuries and heart disease, compared with periods of no flooding.

The researchers from Columbia University used a statistical model to analyze national death data from 2001 to 2018 and calculate how death rates changed in the three months following floods versus normal conditions.

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

They found that the residents of 2,711 counties experienced floods during that time frame, with heavy rain and snowmelt being the top causes of flooding.

“Our results show that floods were associated with higher death rates for most major causes of death, even for rain- and snow-related floods that are less likely to generate rapid emergency responses” than hurricanes, said author Victoria Lynch, a postdoctoral research fellow at the Columbia Mailman School of Public Health.

In particular, the researchers found that rain-related flooding was associated with increased deaths from infectious diseases, while flooding from melting snow was associated with higher death rates from respiratory and cardiovascular diseases.

“There is a hidden burden of exposure to floods that people may not be thinking about having an effect over time,” said author Robbie Parks, assistant professor of environmental health sciences at Columbia. “There is a big infection issue, but even the indirect effects of flooding adding stress can have an impact on cardiovascular health.”

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American