Wildfires could be raising local death rates by two-thirds: Study

Wildfires may be responsible for raising local deaths by about 67 percent in a given month, a new study has found.

Scientists linked 82 “excess deaths” to the devastating blazes that struck Maui, Hawaii, in August 2023 — or two-thirds more fatalities than they would have otherwise expected for that month, per the study, published on Friday in Frontiers in Climate.

During the most intense week of the infernal event, the death toll was 367 percent greater than they would have anticipated for that period, the researchers observed.

“Wildfires can cause a measurable, population-wide increase in mortality, beyond what is captured in official fatality counts,” co-lead author Michelle Nakatsuka, of New York University’s Grossman School of Medicine, said in a statement.

“This suggests the true toll of the Lahaina wildfire was even broader than previously understood,” Nakatsuka added.

To understand the fatal impacts of the blaze, the authors first calculated the “all-cause excess death rate," which refers to how many deaths took place that August beyond what they would have expected. They did so by training a model on Maui County demographic data from August 2018 to July 2023 and by weighting the analysis to eliminate deaths caused by COVID-19.

Ultimately, the researchers found that 82 deaths more than anticipated occurred in August 2023, amounting to an excess death rate of 67 percent.

About 80 percent of these deaths did not occur in a medical context — 12 percent more than in other months — which the authors said could suggest that some people never reached healthcare facilities.

At the same time, they found that the proportion of deaths caused by a non-medical issue leaped from 68 percent to 80 percent.

“Wildfires can cause death in a variety of ways,” co-lead author Kekoa Taparra, of the University of California Los Angeles, said in a statement.

Recognizing that many deaths in the Lahaina case likely occurred due to direct fire exposure, smoke inhalation and burns, Taparra noted that healthcare disruptions and lack of access to medications may have also played a sizable role.

“Wildfires can also exacerbate pre-existing conditions,” he added.

While the total excess count of 82 deaths was less than the region’s official August 2023 fatality count of 102, it was close to the 88 fire-related deaths reported by the Centers for Disease Control and Prevention, per the study.

Nakatsuka attributed the discrepancy to a possible “temporary drop in other causes of death, like car accidents, during the fire period, similar to what we saw during COVID-19.”

“It's also possible that some deaths occurred after the August time window we studied, for example from missed treatments or worsening of chronic conditions,” she said.

Other limitations, Nakatsuka acknowledged, included a lack of access to detailed death certificate data, such as toxicology reports or autopsy findings.

Nonetheless, she stressed the importance of harnessing the public health insights available from this type of post-disaster analysis.

To protect Hawaii from such tragic events in the future, the researchers called for major policy changes — ranging from removing flammable vegetation to improving preparedness.

As native Hawaiians, Nakatsuka said that she and her co-lead author, hoped that wildfire mitigation strategies would focus on indigenous Kanaka Maoli practices, including the revival of traditional agro-ecological systems.

Such an approach, the authors contended, could reduce the odds of destructive wildfires and would also involve removing dry, non-native grasses and restoring pre-colonial water infrastructure.

But in the short term, Nakatsuka said, those exposed to wildfires must be able to access immediate medical treatment.

“Fast, accessible emergency care can save lives,” she added.