Maui wildfire study links lingering metal exposure to abnormal lung function

Residents living near the 2023 Maui wildfires showed elevated levels of several metals associated with abnormal lung function, according to a study published on Monday in the Proceedings of the National Academy of Sciences. Researchers from the University of Hawaii examined urine samples from 1,400 adults. They found substantially higher concentrations of arsenic, cadmium, copper and antimony, among other metals, in people living near areas affected by the fires.

Antimony levels were nearly 40 times higher than those recorded in US biomonitoring data, while manganese was 3.8 times higher, barium 2.3 times higher and arsenic 2.2 times higher. The researchers said the metals may have come from burned buildings, vehicles, electronics and other material destroyed in the fires. Participants with higher metal levels were more likely to have abnormal lung function, including reduced breathing capacity and difficulty moving air in and out of the lungs during standard tests.

The geographical pattern of the lung effects corresponded with the distribution of smoke and ash, the study said. Alika Maunakea, a study co-author and University of Hawaii professor, said the aftermath of the Lahaina fires involved a complex mixture of chemical exposures rather than only smoke from burned vegetation. He said identifying the sources would be important for reducing the risk of renewed exposure.

The fires began in August 2023 after wind spread a brushfire linked to downed power lines. They destroyed Lahaina and killed more than 100 people, according to the source material. The researchers acknowledged that the study could not determine how much of the health impact came directly from the fires.

There was no comparable information from before August 2023, and other possible sources included Hawaii’s geology, diet, historic agricultural and industrial activity, and environmental contamination. Ruben Juarez, another co-author, said disaster response should continue after visible danger has disappeared. The study recommends longer-term monitoring of air quality and consideration of contaminants remaining in soot, soil and debris during recovery efforts.