Tropical cyclones indirectly cause long-term effects on mortality for years beyond the initial event, according to a new study published in the journal Nature. The study, published on October 2, is particularly relevant in the wake of Hurricane Helene and Hurricane Milton, which hit the Southeastern U.S. in September and October, respectively.
There is a “robust increase in excess mortality” for 15 years after a tropical cyclone, with an average of 7,000 to 11,000 excess deaths per disaster, the study said. That goes far beyond the average 24 officially reported deaths that occur directly from a tropical cyclone, the researchers said. Tropical cyclones include hurricanes and tropical storms.
There are figures that point to inequitable distribution of the mortality burden. Among the study’s findings were that infants are the most vulnerable group by risk level, and that Black populations face a larger burden of tropical cyclone mortality relative to white populations.
In the Nature article, researchers Rachel Young and Solomon Hsiang wrote that the findings highlight tropical cyclones “as an important and understudied contributor to health in the United States, particularly for young or Black populations.”
The researchers analyzed the effects of 501 tropical cyclones in the contiguous United States between 1930 and 2015. They proposed several hypotheses to help explain why tropical cyclones result in excess mortality, including economic disruption, changes to the natural environment and to social networks, and increased physical and mental stress.
The study highlights the potential long-term impacts of any public health disaster, in addition to the immediate and direct effects on morbidity and mortality. The findings raise important questions about the potential opportunity to address the triggers of excess mortality—stress, economic disruption, and others—following a disaster to mitigate the risks, particularly for vulnerable populations.
By Sara Merken