Hurricane Helene’s death toll could miss thousands of related deaths
“Excess deaths” caused by indirect effects of a storm can contribute to its overall death toll for 15 years, according to new research.
Before Hurricane Helene made landfall in Florida, meteorologists warned it was likely to cause unprecedented, catastrophic, and deadly flooding. But the devastation across the Southeast has still been shocking, with entire communities submerged in water and blocks of buildings demolished.
"I don't know that anybody could be fully prepared for the amount of flooding and landslides that they are experiencing right now," FEMA Administrator Deanne Criswell told CBS soon after the storm passed through North Carolina, which saw historic levels of flooding.
The full impacts of the storm are still unclear, as ongoing power outages complicate communications and some areas remain physically cut off due to road blockages. Still, early estimates point to Helene being one of the costliest storms in the last century and one of the deadliest.
According to the Associated Press, more than 160 storm-related fatalities have been reported as of Wednesday in Florida, Georgia, North Carolina, South Carolina, Tennessee, and Virginia. With hundreds of people still unaccounted for, that number is expected to rise in the coming days—and, according to a study published today in Nature, for many years.
Co-authors Rachel Young and Solomon Hsiang analyzed the effects of the 501 tropical storms that have struck the contiguous U.S. between 1930 and 2015. Looking at the difference in mortality rates before and after storms, they tracked the “excess deaths” to see how many people died above the usual monthly average and how long that increased rate of death continued. They found that, on average, each tropical storm event causes 7,000-11,000 excess deaths, with health effects persisting long after the initial landfall.
“We thought maybe there'll be six months of delayed effects, maybe a year,” Young, who is a postdoctoral fellow at UC Berkeley, says.
But: “It just kept going up, until it started to decline about 15 years after the storm.”
What counts as a storm-related death?
The findings of their new study left Young and Hsiang, “stunned,” she says. Their statistics far surpass those of the National Oceanic and Atmospheric Administration, which attributes 24 deaths to an average tropical storm. But there has long been contention around these figures, with researchers and storm survivors saying official fatality reports often undercount losses.
Part of this discrepancy is due to the different time frames considered in various counts, as well as the causes of death that are factored in, Young explains. There are what researchers refer to as “direct deaths,” which stem from the storm itself, such as getting hit by debris. These much of are the losses we’re beginning to learn about now from Hurricane Helene.
Then, there are “indirect deaths,” which were included in Young and Hsiang’s study but tend to factor less into government counts, particularly when they occur significantly after a storm. Young says this includes loss of life stemming from ongoing health, economic, and social changes caused by a disaster.
For example, if someone drains their bank account to rebuild, they might not be able to pay for adequate healthcare in the future, or if they have to relocate, they might not have a social network to rely on during future health emergencies.
Plus, there are ongoing environmental factors stemming from storms like pollution that can put someone’s health in continuing danger, and simply the stress of surviving a storm itself can have a significant health impact. These deaths are trickier to attribute to storms, Young says, which is part of why there is a disparity between their study’s statistics and those from NOAA.
“While the cause [of death] recorded isn't necessarily ‘hurricane,’ we know that the hurricanes are creating conditions where people are dying earlier than they would have otherwise,” Young says.
According to Young and Hsiang’s research, tropical storms contributed to more deaths than those from motor vehicle accidents or infectious diseases during the 85-year period they tracked. Their findings build on a growing body of work that posits hurricanes can be significant drivers of public health crises.
The cost of survival
Robbie Parks, an assistant professor of environmental health sciences at Columbia University, has published multiple papers looking at the short-term effects of tropical storms on mortality, finding that even just in the weeks after storms, deaths are often undercounted. Parks, who was not involved in the new study, focuses on how socially vulnerable populations in particular and has found that marginalized communities disproportionately experience health effects.
Looking at Hurricane Helene, Parks expressed concern over the continued loss of electricity and communication, saying these prolonged issues often lead to longer-term health issues. He supports the findings of Young and Hsiang’s study, noting the need to keep aid and attention directed at tropical storm survivors.
“Understanding the impacts of cyclones is critical for understanding how to actually respond to them in the short to long term,” Parks says.
Young says she hopes her study’s publication, coming just days after Helene’s landfall, will spark conversation about the challenges of making people “whole” in the wake of such disasters.
“We're hoping that this study will help shed light onto that longer-term suffering that can occur, help spur faster payouts from insurance companies, [and] help make sure that we are thinking about these folks years down the line,” she says.
