Severe flooding may contribute to higher mortality rates from opioid use in rural Appalachia, according to a study by researchers at Penn State.
The findings - published today (July 20) in the Proceedings of the National Academy of Sciences - are particularly relevant as they come as severe floods are increasing in prevalence and severity due to climate change, said Kristina Brant, assistant professor of rural sociology and co-lead author of the paper.
The study, which examined the effects of severe floods in counties stretching across Appalachia, found overdose deaths significantly increased in the one to two years following a severe flood and persist up to 10 years after. The researchers suggested this link could come from decreased access to treatment, recovery and harm reduction services; increased trauma and instability; and persistent stigma around seeking help for opioid use.
"These findings are important because they underscore that the impacts of environmental disasters and extreme weather events are not just immediate - they can continue to impact our health for years to come," Brant said. "They also underscore that these disasters might be related to health outcomes that we wouldn't typically expect to see a link to, and importantly, it is more vulnerable people and communities that seem to face the largest impacts."
Previous research has shown that floods can interrupt treatment for opioid use disorder, especially treatment involving medications for opioid use disorder. Because floods have also been linked to increased anxiety, depression or post-traumatic stress disorder (PTSD), these treatment disruptions can increase the chance of people using drugs to manage withdrawal or trauma, Brant said.
Brant said she was inspired to conduct the study because of her observations of a major flood that hit Eastern Kentucky in 2021, where she lived before relocating to Penn State University Park. During the disaster, some areas received more than 5 inches of rain in a single weekend. A federal disaster was declared in nine counties, with the Federal Emergency Management Agency assessing $72 million in damage.
"I saw how the floods shifted or derailed some of the systems I was studying," she said. "In these small counties, where a small number of agencies and organizations fill many roles and the professionals who work there wear many hats, I saw how flooding and flood recovery had to become these agencies' main focus - putting other work on hold."
In addition to Brant, this study was conducted by Mengjun Ge, doctoral student in energy, environmental and food economics at Penn State, and Zhen Lei, professor of energy and environmental economics at Penn State.
The team looked specifically at the impacts of severe floods, which they defined as a flood that received a Presidential Disaster Declaration and caused at least one fatality, according to the National Oceanic and Atmospheric Administration. They analyzed opioid overdose death data from National Center for Health Statistics.
Additionally, a second aspect of the study included interviewing 17 stakeholders regarding the floods that occurred in Eastern Kentucky in July 2022 - much of the same area Brant saw hit the year before - to help pinpoint potential causes for the link between flooding events and opioid overdose mortality.
The researchers found that compared to the baseline year - the year prior to the flood event - both overdose death numbers and rates significantly increase in the one to two years following a flood and persist up to a decade after the flood event. Annual overdose deaths in a county increase by 1.1 deaths - or by 26.4% - and the annual overdose death rate increases by 2.5 deaths per 100,000 people - or by 24.5% - relative to the baseline year.
"In rural Appalachia, where a total of 11,744 opioid overdose deaths were recorded during 2000-17, we estimate that severe floods led to 1,368 of those overdose deaths," Brant said.
They also found that deaths significantly increase among individuals with no more than a high school education, but not among those with more than a high school education. Deaths increased significantly for counties that are defined by the Appalachian Regional Commission as economically distressed, but much less so for those that are not distressed.
"What that means is that these impacts of severe floods on overdose deaths are concentrated among more vulnerable communities and populations," Brant said.
Finally, the researchers' qualitative analyses identified four types of mechanisms that may contribute to the long-term impact of floods.
First, participants explained that floods disrupted people's ability to sustain treatment, access recovery resources like support meetings, and access harm reduction resources, caused by the inability to travel to reach services and by facilities' damage or temporary closure. Second, participants explained that the flood exacerbated economic, housing and social instability. For example, the loss of homes and jobs caused stress that could derail recovery and contribute to return to use.
Third, the flood introduced widespread trauma, not just among people who experienced loss but also among those who simply witnessed profound damage to their community. Providers explained that they saw patients use substances to cope with this trauma and resulting mental health issues like PTSD.
"Participants explained that these impacts of trauma were amplified by a larger regional culture which discourages help-seeking," Brant said. "Providers felt that flood-related trauma created an increased need for mental health care, but resistance or inability to seek mental health care amplified the turn to self-medicate."
Brant added that while they can't pinpoint the exact contribution of each mechanism to the overall trend, the correlation between floods and mortality is likely caused by a combination of these factors.
The study suggests, the researchers said, that health care providers should be included in local emergency preparedness and disaster recovery conversations. These providers aren't always included in these conversations, and limiting the impacts of disasters on substance use harms requires the knowledge and expertise that those providers bring.
Brant said that a positive thing that came from the study were stories of how providers and community members came together to limit these negative impacts as much as possible and care for one another after the flooding events.
"One harm reduction provider, for example, explained to me how they were much more prepared to adapt and continue to serve their clients during the 2022 flood because of what they had learned in 2021," she said. "Sharing these lessons with other communities that have not yet faced such disasters could help to instill preparedness and limit future impacts in the event they do experience such an event."
The Social Science Research Institute at Penn State, United States Department of Agriculture National Institute of Food and Agriculture, Eunice Kennedy Shriver National Institute of Child Health and Human Development, and Institutes of Energy and Environment at Penn State helped support this research.
