Floods are associated with a 25% increase in deaths in the US from several major causes

Over the past two decades, major flooding in the US has been associated with up to 24.9% higher mortality rates from leading causes of mortality compared to normal conditions. A new study in the news Naturopathy demonstrates the profound and hidden effects of floods, including floods unrelated to hurricanes, such as those resulting from heavy rain, snowmelt, or ice jams.

Scientists from the Columbia University Mailman School of Public Health led the study in collaboration with researchers from Arizona State University, Harvard University and the University of Arizona.

Until now, there has been a critical knowledge gap in the US over time about the cause-specific risks of flood mortality, and how risks may vary across groups within the population. The study’s findings provide information that could help public health agencies allocate resources.

In the US, population growth alone is expected to result in an estimated 72% increase in the population exposed to annual flooding by 2050, before taking into account the impact of climate change, which is leading to more frequent river, coastal and flash floods.

“Floods are an urgent public health concern as sea level rise, rapid snowmelt and increased storm severity will lead to more destructive and frequent events,” said first author Victoria Lynch, Ph.D., postdoctoral fellow researcher at Columbia Mailman School.

“Our results show that flooding was associated with higher mortality rates for most major causes of death, even for rain- and snow-related flooding that are less likely to prompt rapid emergency responses.”

“Floods have a devastating impact on society in the U.S., but a comprehensive assessment of the ongoing health impacts has been lacking,” said Robbie M. Parks, assistant professor of Environmental Health Sciences at the Columbia Mailman School and senior author.

“Our study is a first major step in better understanding how floods can impact deaths, providing an essential foundation for improving resilience to climate-related disasters in the days, weeks, months and years after they cause destruction .”

After collecting 35.6 million U.S. death data between 2001 and 2018, the researchers used a statistical model to calculate how death rates changed in three-month periods after major flooding, compared to equivalent periods under normal conditions.

Residents of 2,711 counties, covering more than 75% of the U.S. population, experienced at least one major flood during the study period. Heavy rainfall was the most common cause of major flooding, followed by snowmelt in the Midwest and tropical cyclones in the Southeast.

The researchers found that the largest overall increase in death rates among the elderly (24.9%) and women (21.2%) occurred during the month of tropical storms/hurricane-related flooding, with increases in death rates associated with heavy rainfall for infectious diseases. diseases (3.2%) and cardiovascular diseases (2.1%). Snowmelt-induced flooding was associated with higher mortality rates for respiratory diseases (22.3%), neuropsychiatric diseases (15.9%), and cardiovascular diseases (8.9%).

The increase in infectious diseases is likely related to disruptions in drinking water and sewage infrastructure that can lead to waterborne disease transmission. Chronic and neuropsychiatric disorders may be related to stress due to persistent flood-related disturbances. Socioeconomic factors that determine health outcomes in communities vulnerable to flooding, as well as the ability of residents to evacuate during emergencies and respond to their aftermath, can also play an important role.

“Most of our understanding of the health impacts of flooding comes from major events such as Hurricane Katrina or Harvey, which, despite their devastating effects, are examples of a larger phenomenon,” said Jonathan Sullivan, assistant professor of Geography, Development and Environment at University of Arizona and co-author.

“Our study shows that even floods caused by melting snow or heavy rain, each uniquely caused by changes in climate and development, increase mortality rates months later and provide critical knowledge about how to manage and respond to floods can adapt.”

Previous research on climate and health by the authors of this article has found increased mortality rates following tropical cyclones in the US, including a disproportionate increase in deaths in socially vulnerable communities of color. tropical cyclones are associated with the spread of water-borne infectious diseases.

Other co-authors are Aaron Flores, Arizona State University; Sarika Aggarwal and Rachel C. Nethery, Harvard Chan School of Public Health; and Marianthi-Anna Kioumourtzoglou, Anne E Nigra and Xicheng Xie, Columbia Mailman School of Public Health.