August 8, 2024

NIOSH Evaluates Maui Wildfire Responders’ Chemical Exposures

A NIOSH analysis of potential chemical exposures among firefighters, ocean safety officers, police officers, Hawaii National Guard servicemembers, and others who responded to wildfires in Maui County in August 2023 is detailed in a health hazard evaluation (HHE) report published last month (PDF). The agency evaluated biomarkers of exposure to lead, cadmium, manganese, and selenium, as well as per- and polyfluoroalkyl substances (PFAS) and polybrominated diphenyl ethers (PBDEs) in responders’ blood. NIOSH also evaluated biomarkers for chromium, nickel, arsenic, and organophosphate esters (OPEs) in responders’ urine. Data on responders’ demographics, work, and potential exposure characteristics were collected via questionnaires for analysis alongside their biological samples. The HHE report lays out the agency’s findings and recommends controls for limiting first responders’ hazardous chemical exposures during wildfires and debris cleanup.

Beginning Aug. 8, 2023, wildfires on Maui, Hawaii, burned more than 2,200 structures and led President Joe Biden to declare national and public health emergencies. The communities of Kula and Lahaina suffered “catastrophic damage,” according to the HHE report. About 100 people lost their lives to the Lahaina fire.

Maui County firefighters, police officers, and ocean safety officers—members of the island-wide public lifeguard service—along with other Maui Department of Public Works personnel participated in initial response activities, such as fire suppression, structure protection, water rescue, and evacuation. Firefighters, police officers, and Hawaii Air and Army National Guard servicemembers also participated in urban search and rescue efforts in the aftermath of the Lahaina fire.

In late August, the Maui fire chief requested assistance from the Federal Emergency Management Association in evaluating firefighters and ocean safety officers who may have been exposed to hazardous chemicals during response efforts, and FEMA tasked NIOSH with public health surveillance of all Maui County first responders. Hawaii’s National Guard emergency management specialist requested similar assistance from NIOSH in September.

NIOSH’s evaluation found that some responders had markers for exposures to inorganic elements at or above either relevant occupational exposure limits (OELs) or levels found in the general U.S. population. Almost all responders had detectable levels of PFAS, PBDEs, and OPEs. However, the report cautions that most people in the general U.S. population have these chemicals in their bodies. PFAS may be found as contaminants in water systems and in some food, packaging, and household goods, while PBDEs and OPEs are common components in flame retardants. One participant had a sum of PFAS chemicals in their blood serum slightly above the threshold for health screening proposed by the National Academies of Science, Engineering, and Medicine. At least one participant had a result above the reference value for five out of 11 PBDE chemicals and four out of eight OPE chemicals.

Analysis of participants’ occupations and exposure markers found that workers categorized as “other Maui County employees” were more likely than other participant subgroups to have chromium levels exceeding the OEL. Police department employees had higher median manganese concentrations, and firefighters had the highest median sum of PFAS concentrations. NIOSH did not find clear patterns for responders’ self-reported exposure times or personal protective equipment use. “More sophisticated analyses beyond the scope of this report would be needed to help elucidate the contribution of tasks and PPE to the biomarker measurements,” the HHE report states.

The report also includes a list of recommended controls for preventing first responders’ exposures to inorganic elements, PFAS, flame retardants, and other chemicals during wildfires and fire debris cleanup. These include minimizing dust exposures, providing annual training on wildfire best practices, maintaining fire response gear, and ensuring that responders continue to wear PPE after active fires are extinguished. NIOSH also advises employers of first responders to develop and implement PFAS exposure control plans. PFAS are associated with a range of health effects such as increased cholesterol levels, increased risk of high blood pressure in pregnant women, and increased risk of testicular and kidney cancer, the report says.

NIOSH’s report on Maui first responders’ chemical exposures can be downloaded as a PDF from the agency’s HHE report library.