What’s in the burnt remains of the LA wildfires?
DRI scientists deployed to Los Angeles to collect ash, soil, and dust samples from burn zones in the hopes of illuminating the unique risks of wildland-urban fires.
image: DRI's Vera Samburova collecting ash samples from the burnt remains of a Los Angeles home.
Credit: Vera Samburova/DRI
Wildfires tore through Los Angeles in January 2025, burning more than 16,000 structures, uprooting neighborhoods and displacing entire communities. As the infernos raged, DRI scientists with a wide range of expertise in soil science, air quality, and post-wildfire impacts put together a plan for collecting ash, dust, soil, and building material samples from the burn zones. To them, these urban fires presented a unique opportunity to understand how materials like plastics, metals, and even lithium batteries from electric cars can transform into environmental contaminants when they burn.
“The community members affected by these fire scars will need this information in order to make decisions about whether to rebuild and how to safely live in these areas after risk reduction through proper cleanup” said Vera Samburova, Associate Research Professor of Atmospheric Science at DRI who led the effort. “This is an important thing to understand all across the West, because fires in the wildland-urban-interface are increasing everywhere, including in Nevada.”
Samburova’s group requested emergency funding from institutional leadership and an ongoing wildfire research project to set out to Los Angeles without waiting for lengthy grant approval processes. The longer they waited to collect ash and soil samples, the more the samples would be impacted by rain, wind, and other environmental influences.
The scientists connected with homeowners impacted by the Palisades and Eaton fires and received permission to collect samples from their burnt properties. Protected by hazmat suits, Samburova and two graduate students carefully navigated the hazards of the torched landscape, trying to identify the burnt remains of plastic fences, ceilings, and the former walls of someone’s home.
“When I talked to the homeowners who allowed us to go to their former houses and collect the samples, they said, ‘We really want to know what toxic compounds, ash, and dust are in the air and on our property’,” Samburova said. “They’re really concerned, especially people whose homes remained standing in otherwise charred neighborhoods.”
The research team also worked with Los Angeles County to access wildlands within the burn zones and collect ash samples to compare to the urban ones. More than 200 samples in total were collected from homes, apartment complexes, Eaton Canyon, and a park in Palisades. While in transit along the famed Pacific Coast Highway, they noted the smell of ash in the air and pulled over to collect sand samples from a Malibu beach.
“We expect the wildlands samples to differ quite a lot from the suburban and urban ones,” said Hans Moosmüller, Research Professor of Physics who is helping lead the effort. “In the suburbs, you have palm trees and bushes and all kinds of plants which aren’t growing in the wildlands. Plus, you have all the human-made materials — cars and gas tanks and propane bottles and medications — things we normally don’t think about in terms of wildland fires. Understanding how these materials break down in fires is critical, because the wildland-urban interface has been growing dramatically in the US.”
Samburova has specialized expertise in air quality and soil modifications following wildfires and has previously collected ash samples from the Dixie, Beckwourth Complex, Caldor, and Mosquito Fires, as well as from fires around Reno. The LA fires provide a unique opportunity to examine a more urban burn environment with the potential to contain more heavy metals, plastics, and other potentially toxic elements. The ash samples will allow her and other DRI experts to examine the toxins and metals present – contaminants that can impact soil and water quality. Using specialized equipment like the Portable In-Situ Wind ERosion Lab (PI-SWERL), developed by DRI scientists Jack Gillies, Vic Etyemezian, and George Nikolich, the research team can also investigate how the ash impacts air quality when disturbed by wind or remediation efforts.
“We’ve collected ash, dust, and soil samples from fires which burned three years earlier, where we can still see a thick layer of ash on the ground,” Samburova said. “Ash, dust, and soil can turn into dust and impact air quality for years to come. That’s why it was important to collect these samples and bring them to DRI because DRI is unique — there are so many specialists in one place and we can perform a comprehensive analysis.”
The next step is to identify funding sources to support the analysis work and collaborators who can add expertise to the research team. Samburova and Moosmüller will work with experts in DRI’s Environmental Analysis Facility, Luminescence Lab, and others to examine the ash samples from a range of perspectives, and invite external collaborators to join the effort. The ultimate goal, the researchers say, is to get answers for the community members living in or near the burn scars — answers which will help inform communities throughout the West, and the world, in the years to come.
The Los Angeles wildfires happened only months after DRI and the DRI Foundation held the AWE+ 2024 summit, a gathering of stakeholders including scientists, policymakers, industry leaders, non-governmental organizations, and community members. The theme centered on “Wildfire Recovery and Resilience”, with discussions about the devastating impacts of wildfires in the West, paths to recovery, and lessons learned from recent wildfires. The collaborative forum promoted cross-sector viewpoints with the goal of accelerating the transformation toward resiliency in managing risks from wildfires.
To support our research on wildfire impacts, air quality, and other science that matters now, visit the DRI Foundation website.
Related Research:
What We Know About Wildfire Risk and Prevention
AWE+ Wildfire Recovery and Resilience Summit 2024