Over the past week, the official death toll from Hurricane Helene has surpassed 100 as the vortex creeping inland from Florida submerged homes and swept away cars. But the full weight of lost lives will be realized only years from now — and it could number in the thousands.
A paper published in the journal Nature on Wednesday lays out the hidden toll of tropical storms in the continental United States. Looking at 501 events from 1930 to 2015, researchers found that the average tropical storm resulted in an additional 7,000 to 11,000 deaths over the 15 years that followed.
Overall during the study period, tropical storms killed more people than automobile crashes, infectious diseases and combat for U.S. soldiers. It’s such a big number — especially compared with the 24 direct deaths caused by hurricanes on average, according to federal statistics — that the authors spent years checking the math to make sure they were right.
“The scale of these results is dramatically different from what we expected,” said Solomon Hsiang, a professor of global environmental policy at the Doerr School of Sustainability at Stanford University, who conducted the study with Rachel Young, the Ciriacy-Wantrup postdoctoral fellow at the University of California, Berkeley.
The pair used a technique that has also provided a more complete understanding of “excess deaths” caused by Covid-19 and heat waves. It works by looking at typical mortality patterns and isolating anomalies that could have been caused only by the variable under study — in this case, a sizable storm.
Previously, researchers examined deaths and hospitalizations after hurricanes over much shorter periods. One study published in Nature found elevated hospitalizations among older Medicaid patients in the week after a storm. Another, in The Journal of the American Medical Association, associated higher death rates with U.S. counties hit by cyclones. A study in The Lancet found that across 14 countries, cyclones led to a 6 percent bump in mortality in the ensuing two weeks.
But despite mounting interest in the health effects of natural disasters, nobody had examined such a long period after a storm. That perhaps stands to reason: After someone survives a hurricane, it’s hard to imagine what sequence of resulting events could lead to death more than a decade later.
The study doesn’t answer those questions with certainty. But public health literature contains some clues.
“It makes a lot of sense that a hurricane, or tropical cyclone — which is a substantial ‘shock’ to a community’s functioning — would lead to long-lasting effects,” said Sue Anne Bell, an assistant professor at the University of Michigan’s Center for Global Health Equity, who reviewed the study.
Dr. Bell has researched the first-order impacts of natural disasters, such as ramifications for dementia patients whose routines may have been disrupted and care teams fragmented. Cancer patients who lived through Hurricane Katrina in 2005 had lower survival rates even years later, which probably had to do with disruptions to their treatment.
But the authors also suggest more subtle, long-term changes that could overwhelm hurricane survivors. Borrowing from retirement savings to cover an uninsured loss might lead to tougher financial circumstances down the line. The stress of losing a home could worsen heart conditions that ultimately prove fatal. Hurricanes can erode local government capacity, draining resources for priorities like road safety or firefighting.
The study found that Black people bore a disproportionate mortality burden from tropical storms, partly because more live in hurricane-prone areas, but potentially also because they tend to have fewer financial resources and less access to health care.
And there are psychological effects, which can damage physical health. David Abramson, a clinical professor at New York University’s School of Global Public Health, followed a group of Katrina survivors for years. He noticed an increase in substance abuse over time, which could be connected to the trauma of seeing their lives upended.
“A lot of these folks were working really hard, climbing the ladder — all of a sudden, some event drops them back to the bottom of a ladder, and that’s very dispiriting,” said Dr. Abramson, who also reviewed the study. “It leads to a fatalism, giving up a little bit, risk behaviors.”
Cumulatively, the study found, storms weigh most on states that are hit repeatedly, like Florida, where Dr. Hsiang and Dr. Young attribute 13 percent of overall deaths to the stormy climate.
Individual storms, however, are a heavier blow in states that are hit only occasionally, possibly because their systems and infrastructure are less prepared for it.
The threat from hurricanes is expected to increase because of climate change. Although deaths rose throughout the 20th century as the population grew on the Atlantic and Gulf Coasts, Dr. Young and Dr. Hsiang’s data shows an inflection point around 2001, as storms started to become more frequent.
For that reason, even though direct deaths from storms have declined over the decades, Dr. Hsiang urged more research into the much greater number of deaths that occur long after the skies have cleared.
“When things are invisible, politicians can’t respond to it, communities can’t fix it,” Dr. Hsiang said.
The post Hurricane Helene Deaths Will Continue for Years, Study Suggests appeared first on New York Times.
