In August of 2023, a series of wildfires broke out across Maui, killing more than 100 people, destroying thousands of homes, and causing billions in damage. Noelani Ahia, who is Kanaka Maoli and co-founder of Maui Medic Healers Hui, helped mobilize nearly 600 volunteers in Lāhainā, including doctors, nurses, and therapists.

Three years later, the housing and health crises remain acute. Maui Medic Healers Hui runs a free clinic, but Ahia wishes it had 10 more to address the community’s needs. “The fire may be out, but the catastrophe is not over by any stretch of the imagination,” she said.

The devastation extended well beyond the lives lost and buildings destroyed. Research published last year by researchers with the University of Hawaiʻi at Mānoa’s Maui Wildfire Exposure Study, or MauiWES, found that more than 1 in 5 residents had reduced lung function. Now, new research from the same project has found elevated levels of toxic metals in the island’s residents months after the fires, with higher exposure associated with impaired lung function.

The findings offer further evidence that the health consequences of catastrophic wildfires can persist long after the flames are extinguished and the smoke clears. “What we consider and sometimes look at as a one-time event isn’t really one-time anymore,” Alika Maunakea, who is Kanaka Maoli and co-director of MauiWES, told Grist.

Researchers don’t yet know how much of the contamination came from the fires and how much was already present in the environment. That distinction matters as wildfires increasingly race through towns like Lāhainā and cities like Los Angeles, where burning homes, cars and infrastructure can leave contaminants that people encounter for months or years afterward.

“We have traditionally thought about wildfire exposure primarily through the lens of smoke,” Maunakea said in a press release. “But when an entire community burns, we are dealing with a much more complicated exposure environment.”

Researchers must also understand what contaminants were already present, what the fire may have released, and what entered residents’ bodies, he said. The research, which studied 1,400 adults across Maui six to 18 months after the fires, measured 24 metals in urine samples.

It found that participants had higher concentrations of several metals than people in a nationwide health survey conducted before the fires. That included 2.2 times as much arsenic, 2.3 times as much barium, and 3.8 times as much manganese. Antimony, which is used in flame-retardant materials and has been previously linked to lung irritation, stomach pain, and other symptoms, was found at levels nearly 40 times higher.

Because the researchers lack comparable data from before the fires, they could not determine how much of the metal exposure resulted from the disaster. Maunakea told Grist answering that question is the next step for the project, which has received a $3.6 million grant from the National Institute of Environmental Health Sciences. That work will include investigating whether and to what degree past agricultural and industrial activity contributed to the contamination.

“It’s important to realize that these are all part of settler colonialism,” Ahia said. “So what we’re looking at is confounding factors that are to the detriment of the health of our local people.”Decades of plantation agriculture altered water systems, introduced herbicides, and displaced native plants, leaving a legacy on the islands that is still felt today. Disasters like fires and storms can compound those ongoing environmental problems.

“If we begin the story when the fire starts, we miss the decisions that shaped the landscape and the community’s ability to respond,” said Katie Kamelamela, who is Kanaka Maoli and an assistant professor at Arizona State University based in Hawaiʻi. “Micro climate change acts on places already shaped by histories of land ownership, water diversion, development, and unequal access to resources.”

Kamelamela said true recovery must look beyond the fire. “I want recovery to be measured by whether people can remain in their communities, care for ʻāina, and pass on their knowledge and practices in place,” she said, using the Hawaiian word for land, which carries deeper meaning and relationship than property or mere place. “Rebuilding should not recreate the same conditions that left people at risk. Caring for ʻāina and caring for people need to be funded and planned together.”

Maunakea said the multitude of intersecting pressures is one reason why he wanted to pursue this research. As climate change continues to accelerate, long-standing issues facing Native Hawaiians like housing, the harms of tourism, and the legacy of plantations can amplify problems. “We worry that disasters like this that we experience on Maui, as well as the floods and other storms that we’re experiencing now, is just going to continue widening the gaps in health disparities that already exist in those populations,” he said.

Moving forward, the project will not just identify health risks but also help residents respond to them. Study participants receive their results, discuss them, and meet with health professionals. “People now know that there’s these types of potential hazards, and what to do about them is a big concern,” Maunakea said. “We still don’t have all the answers for sure, but we are taking the next steps to get a better picture and inform our community around it.”