Hurricanes have become deadlier in recent decades, study shows
Hurricanes have become deadlier and have disproportionately affected the most socially vulnerable communities, according to a study released Wednesday in Science Advances. The study estimated that, from 1988 to 2019, Atlantic hurricanes caused nearly 20,000 direct and indirect deaths up to a month after the event. The majority of deaths occurred from cyclones after 2004. Ninety percent of all deaths were in more socially vulnerable county groups, including older adults and Indigenous, Black and Brown communities. Lead author Robbie Parks said he was shocked but not surprised by the findings, given behemoth storms such as Katrina, Sandy and Irma. Its quite hard to tell just by reading through documentation whether the burden is going up or not, and that was our attempt to do so, said Parks, an environmental epidemiologist at Columbia University. Knowing those numbers allows resource allocation and planning. The team analyzed tropical cyclone and death registration data from 1988 to 2019 to estimate the number of excess deaths caused by a cyclone up to a month after the event. Using statistical models, the team compared the number of deaths that occurred during a hurricane event to the number of deaths that would have occurred if the cyclone had not happened. The team only calculated excess deaths for the contiguous United States, leaving out powerful hurricanes like Maria, which ravaged Puerto Rico and was blamed for about 2,975 excess deaths. Of 179 tropical cyclones analyzed, the team found Hurricane Katrina caused the most deaths overall in the study, at 1,491 excess deaths, which is slightly higher than the official estimate of 1,170. The second deadliest was Irma in 2017, which the study estimated took 1,202 lives. Sandy in 2012 was third deadliest, at 1,193 deaths. The team found the single largest death toll in a county 719 excess deaths occurred in Orleans Parish after Katrina in 2005. Rita, also in 2005, caused the second highest number of deaths in a single county in Harris County, Tex., at 309 excess deaths. (Houston is in Harris County.) Other high tolls were in Broward County, Fla., after Matthew in 2016 (185 excess deaths) and in Nassau County, N.Y., after Sandy in 2012 (178 excess deaths). Deaths occur after a tropical cyclone for many reasons, including from injuries but also infectious, parasitic, cardiovascular and respiratory diseases, according to previous research by Parks and others. Hurricanes can also disrupt power, transportation and the ability to obtain food or shelter, which can exacerbate underlying conditions . The brunt of the impact is felt by the people who already suffer a debilitating health condition such as heart disease or diabetes, said Raul Cruz, a biostatistician at Indiana University School of Public Health-Bloomington who was not involved in the research. His research on Maria showed excess deaths were higher among men, older populations and those with heart disease, for instance. The majority of excess deaths in the analysis occurred in the past 15 years. In areas affected by tropical-storm-force winds, 70 percent of deaths have occurred since 1988, while zones that endured more intense hurricane-force winds which are more rare saw 83 percent of their deaths in that same period. Parks said the growing burden can be chalked up to three things. First, human-induced climate change caused hurricanes to more rapidly intensify, especially near the coast. Second, as the population grows, more people are moving to the coast and increasing their exposure to flooding and strong winds. Last, he said, many of the communities on the coast are more vulnerable socioeconomic classes and they feel the brunt of the damage and may be less prepared or have fewer resources to recover. The thing that was kind of shocking is the way that the large majority of the deaths were in ... socially vulnerable areas compared with the rest of the country impacted by cyclones, said Parks. The poorest places in the states are by the coasts, which are repeatedly battered by cyclones. Sue Anne Bell, a nurse scientist and professor at the University of Michigan who studies the health effects of disasters, was not surprised by the studys finding. The study does confirm what we know anecdotally that extreme weather events are harmful to health, said Bell, who previously found that older adults are more likely to be hospitalized after a disaster but may have less access to doctors. Those groups that have more challenges meeting their health needs during normal times will have even greater risks during these events. The researchers said they hope these findings can be used to drive changes in how communities prepare for, respond to and recover from disasters. As part of his own work, Cruz recommended the development of early warning systems for public health issues (including diarrhea, allergies and infectious diseases) that take into consideration extreme weather events. Parks said better fortifying structures can help, along with using additional resources to help evacuate people safely and to make evacuation the norm. Its a problem thats not going to go away, said Parks. We can choose how to allocate our resources to protect the most vulnerable.