Lahaina wildfire study raises concerns over long-term exposure

Residents in Lahaina, Hawaii, are raising concerns about health risks as rebuilding continues in the wildfire burn zone.

According to AP News, preliminary results from the University of Hawaii’s Maui Wildfire Exposure Study suggest that survivors who live or work in the affected area show signs of ongoing exposure to harmful heavy metals.

The research indicates that participants in the study have elevated levels of substances linked to respiratory, cardiovascular and mental health issues, as well as increased cancer risk.

This contrasts with earlier assurances from state health officials and the U.S. Army Corps of Engineers that the burn zone was cleared of environmental risks after debris removal in 2024.

Community members have expressed doubts about the safety of returning to their homes, with many reporting worsening health outcomes since resettling.

Residents’ ongoing health fears

Maria Linz, a Lahaina resident and program manager for the Hawaii Community Lending recovery initiative, said: “I am terrified about the health impacts and the future for everyone in Lahaina.

“The dust that comes in isn’t the same. The dust now is black. It used to be red.”

Other residents, such as hotel worker Damion Emeson, have also voiced concern. He said: “There’s a lack of trust with certain government agencies.

“It’s not their families that are living there.”

Researchers reported that survivors living or working in the burn zone were more likely to have higher levels of toxins in their systems. Participants also described worse health conditions compared to those who had not returned.

Findings from Maui wildfire exposure study

The University of Hawaii team analysed urine samples from more than 1,200 survivors.

Ruben Juarez, a health economics expert with the University of Hawaii Economic Research Organisation, explained that about 20% of participants showed elevated levels of metals such as arsenic and nickel.

Juarez said: “Residents living back in Lahaina are telling researchers that they’ve experienced worse health outcomes after moving back home.”

The team noted that exposure could not yet be linked definitively to the burn zone, as soil testing is still limited and unaffected populations were not included in the study.

Researchers emphasised that results highlight a need for ongoing environmental monitoring and population-level studies.

Official assurances and testing gaps

The U.S. Army Corps of Engineers reported in 2024 that its clean-up operations had removed debris and tested soil to ensure sites were suitable for rebuilding.

It said that hundreds of samples were collected, although most came from the ash footprints of burned structures.

State health officials added that testing of soil, sand and water did not reveal heavy metals in amounts expected to impact health.

Stephen Downes, communications director at the Hawaii Department of Health, said in a statement that blood tests from 557 residents between December 2023 and February 2024 did not show widespread elevated lead exposure.

Health Director Dr Kenneth Fink said at the time: “We did not expect to find health impacts caused by toxins in the wildfire ash.”

Experts question official conclusions

Researchers and external experts have warned that these findings may not fully capture long-term risks.

Dr John R Balmes, professor emeritus of environmental health sciences at the University of California, Berkeley, said: “I’m not surprised at all that the people who have been exposed more are having more problems.

“There is still ash that comes down from the smoke. I’m sure there’s been an effort made to clean the burn area, but can you get every single bit of soil that might contain toxic materials?”

Balmes also noted that while clean-up reduced many risks, contamination could persist in soil and dust.

Stanford University researcher Jessica Yu added that wildfire pollutants can spread miles beyond burn sites and remain for extended periods.

Calls for more monitoring and protection

Researchers involved in the Maui Wildfire Exposure Study told lawmakers that unknown risks remain.

Co-lead investigator Alika Maunakea said: “We just don’t know much about the ongoing exposures, and potentially the re-exposures as rebuilding plays out and people are returning back to their properties.

“We suspect it could still be either present or there are potential sources of re-exposures in the environment. We don’t know.”

Health experts recommended practical steps such as wearing N95 masks outdoors during windy conditions and using home air filters.

Balmes said: “The most important thing is to keep exposure to the ash and the dust down as much as possible.”

He added that public health risks should decline over time, but ongoing vigilance remains important.

Relevance for fire and safety professionals

The situation in Lahaina highlights the importance of long-term monitoring in post-wildfire recovery zones.

Fire and safety professionals can note the gap between official clearance processes and subsequent research findings, which shows the need for clear risk communication.

The findings underline how recovery efforts may intersect with public health concerns, requiring collaboration between emergency services, environmental scientists and community organisations.

For those involved in wildfire management, the case also shows how dust and soil contamination can persist well after debris removal.

Lahaina wildfire study raises concerns over long-term exposure: Summary

AP News reported that University of Hawaii researchers are studying residents of Lahaina, Hawaii.

The Maui Wildfire Exposure Study tested more than 1,200 survivors.

Preliminary findings showed elevated levels of heavy metals in some participants.

About 20% of residents tested showed higher levels of arsenic and nickel.

Health impacts reported included respiratory, cardiovascular and mental health issues.

State health officials previously said the burn zone was safe.

The U.S. Army Corps of Engineers cleared debris in 2024.

Soil testing by the Corps focused on ash footprints of buildings.

The Hawaii Department of Health tested 557 residents for lead exposure.

Officials reported no widespread elevated lead levels in those tests.

Experts said heavy metals may persist in the environment.

Wildfire contaminants can travel far and remain over time.

Researchers called for more environmental monitoring.

Residents expressed distrust of official assurances.

Some community members reported worsening health after returning.

Health experts recommended limiting exposure to dust and ash.

They suggested N95 masks and air filtration indoors.

Researchers said public health risks will take years to assess.

They added that further testing is required to clarify long-term exposure.