Wildfire ash collected in Lahaina has elevated levels of toxic substances, according to the state Department of Health.
Officials found that arsenic was more than 12 times the action level. Elevated levels of antimony, cobalt, copper and lead were also detected in Lahaina.
The ash samples were collected in early November from 100 Lahaina properties.
Meanwhile, air quality monitoring in fire-affected areas of Maui continues to show “good” air quality, meaning contaminated ash has not become airborne.
The DOH and Environmental Protection Agency have more than 50 real-time air monitors installed in Lahaina and Upcountry Maui. The sensors measure particles 30 times smaller than a human hair.
Kathleen Ho, the DOH's deputy director for environmental health, described how the sensors change color depending on the air quality.
“If the ash is airborne and it's picked up by the purple sensors, the color in the purple sensors will become yellow or orange or red. If the sensors are green, which they've been showing, there doesn't seem to be any particulate matter in the air," she said.
"The heavy metals are stuck to the ash and if the ash is not airborne, the greatest risk is for ingestion and inhalation, so if you’re going to go into the burn area or exposed to ash, make sure you wear a mask and use the proper PPE," she continued.
A dust control agent and soil stabilizer called Soil-tac was applied to Lahaina burn areas in October by the EPA. Soil-tac helps prevent ash and dust from becoming airborne and minimizes contaminant runoff.
Air monitoring is also taking place in Kula during Phase 2 debris removal, to ensure air quality isn’t impacted.
Similar air sampling will be conducted in Lahaina when debris removal begins there early next year.
Lahaina and Kula residents can monitor real-time air quality at fire.airnow.gov or by downloading the AirNow or IQAir Visual mobile apps.
