Maui Wildfire Residents Show Elevated Toxic Metals in Bodies Months After Fires
A University of Hawaiʻi study found residents exposed to 2–40 times higher concentrations of various metals than a pre-fire national baseline, with associations to impaired lung function.
What happened
The August 2023 Maui wildfires killed over 100 people and destroyed thousands of homes. Research from the Maui Wildfire Exposure Study (MauiWES), which measured 24 metals in urine samples from 1,400 adults six to 18 months after the fires, found elevated levels of arsenic (2.2×), barium (2.3×), manganese (3.8×), and antimony (nearly 40×) compared to a nationwide pre-fire health survey. Higher metal exposure was associated with reduced lung function. Researchers cannot yet determine how much contamination came directly from the fires versus pre-existing environmental sources, though a $3.6 million National Institute of Environmental Health Sciences grant will fund further investigation into that distinction.
Context
The findings demonstrate that catastrophic wildfire health consequences extend far beyond acute smoke exposure and the immediate post-fire period. As wildfires increasingly strike populated areas—including Los Angeles—understanding persistent chemical exposures from burned homes, cars, and infrastructure becomes critical to long-term public health response. In Maui's case, the metal contamination occurs within a context of longstanding environmental degradation: decades of plantation agriculture altered water systems, introduced herbicides, and displaced native plants, creating compounding health vulnerabilities for Native Hawaiian communities. Researchers note that climate change, housing crises, tourism impacts, and colonial legacies together may amplify existing health disparities in affected populations. Recovery efforts will require identifying what contaminants residents can encounter months or years after fires and determining how to mitigate exposure—a step the study is now supporting by providing participants their results and connecting them with health professionals.
What's disputed
Researchers lack comparable pre-fire metal exposure data from Maui residents, so cannot definitively quantify how much of the measured contamination resulted from the fires versus historical agricultural and industrial activity.