Climate-amplified wildland–urban interface disasters create persistent internal metal mixtures associated with pulmonary impairment

This research article investigates persistent internal metal mixture exposure and pulmonary function in adults following the August 2023 wildland-urban interface (WUI) wildfires on Maui, Hawai‘i. The study utilised a community-engaged cohort (Maui Wildfire Exposure Study, MauiWES), enrolling 1,400 adults from multiple Maui regions 6-18 months post-disaster. Paired biological assessments included measurement of 24 urinary metals and standardised spirometry, enabling exposure-response analysis. Comparisons with US NHANES data contextualised findings relative to national background levels.

Key findings include:

• Participants exhibited elevated urinary concentrations of multiple metals, with highest levels in the most affected regions.
• Higher cumulative metal burden was consistently associated with pulmonary impairment, including increased odds of abnormal spirometry and declines across multiple lung-function parameters.
• Arsenic, cadmium, copper, and antimony were dominant contributors to the positive mixture index.
• Short-term air monitoring alone may underestimate long-term toxic burden;
• The authors recommend integrating biomonitoring and longer-term respiratory surveillance into WUI disaster response and recovery.