L.A. wildfires: With no clear cleanup standards, how to test for toxic soil
January 8, 2026
In summary
Ash rained down and smoke blanketed Los Angeles during the 2025 wildfires, leaving behind a toxic legacy in soil and homes. Without a federal or California mandate, nonprofit, academic and local groups offer testing for homeowners.
As the Palisades and Eaton fires burned last January, and for weeks afterward, clouds of ash blanketed the city. Contained in that ash were microscopic bits of heavy metals and synthetic chemicals from the homes that were consumed in the megafires. The Los Angeles hazards aren’t unique: they’ve become part of the wildfire legacy in wildland-urban interfaces throughout California.
Modern houses are full of synthetic chemicals found in everything from paints and finishes, to electronics and upholstered furniture, to cookware. After the Camp Fire, a California Air Resources Board analysis in 2021 traced heavy metals like arsenic and lead that traveled in smoke from Chico all the way to San Jose. Last year, both in Los Angeles County’s fire-scarred neighborhoods and downwind of them, people wondered what exactly was in their gardens, yards, sandboxes and playgrounds – and raised questions about how risky it is to interact with the environment after a major wildfire.
Yet FEMA, the California Environmental Protection Agency, and L.A. County chose not to perform soil testing. FEMA instead ordered that the top few inches of soil be removed from burned properties. Local government and non-governmental organizations stepped in to provide testing and education, but no clear standard for testing soil or cleaning up homes safely exists.
Here are the answers to questions frequently asked by fire survivors as well as those who’ve experienced their fallout.
No federal or California mandate establishes one. FEMA had a policy of collecting soil samples to test for hazardous chemicals, but in 2020 reversed its routine. The agency made an exception in Hawaii in 2023, where there was a lack of baseline data about what was in the soil.
CAP.LA will come to a property to do testing when a homeowner fills out this form and they say they give results in about a month.
Residents can mail or drop off soil samples they collect for USC Clean’s project after they register online for an identifying number.
Separately, Los Angeles County Department of Public Health offers a drop-off soil testing program too, prioritized for people within the burn footprints of the fires in Pacific Palisades and Altadena.
Without federally-sponsored testing, local government, nonprofit and academic groups have stepped in: LA County Public Health set aside up to $3 million from their Lead Paint Hazard Mitigation Program to fund free soil lead testing for residents living within and downwind of the Eaton and Palisades Fires burn areas. The R&S Kayne foundation funded CAP.LA – the Community Action Project of Los Angeles – which connects people with free soil and water testing, as well as offering targeted advice for individual homeowners. Another soil testing project, USC Clean, is funded by significant grants from FireAid, a non-profit, along with support from L.A. Care, a public, locally-operated Medi-Cal managed care plan.
Lots of substances get released when houses and cars burn, including plastics, chemicals, and metals. Metals can drop out of the ash and settle on soil, grass and trees – hanging around the local environment after structures burn. Lead may become airborne during a fire as toxic lead vapor or settle in ash and soil. That’s a worry because no safe exposure level to lead exists. Exposure to lead and other heavy metals can pose serious health risks, especially to children, pregnant individuals, seniors, and those with existing health conditions. When people touch contaminated soil or surfaces, hand-to-mouth contact is a hazard.
When scientists did precise studies of the soils after the devastating 2021 Marshall fire in Colorado, they found higher levels of metals like lead, chromium, copper and zinc in the burned areas than non-burned areas – but overall the levels were below the threshold for danger for human health.
But the risk is different for every property – so getting your soil tested is important. In Los Angeles County, CAP.LA has helped, and so has the LA Department of Public Health – which prioritizes properties located in the Eaton and Palisades burn areas for free soil testing – as well as the USC Clean Project. CAP.LA’s map shows aggregated self-sampling results for lead testing in soil.
In general, the risk depends on how your soil and outdoor spaces are used. Young children who play in the dirt often are more at risk than adults. People who eat often from their gardens are also at a slightly higher risk – though overall, food from gardens is safe (with precautions), even after fires.
Experts advise taking into consideration the frequency of your exposure to build a profile of your risk – with greater concern for is this a children’s play area or garden where you go multiple times a day compared to a burned building which will eventually be covered by a new foundation of a future house.
Many parts of California have long had a problem with lead: lead-based paint and leaded gasoline left their mark on the landscape. Even before the fires, a study of 600 soil samples from urban areas across Los Angeles County found an average of 180 ppm of lead in soils.
The California Department of Toxic Substances Control uses a level of 80 parts per million in residential soil as a screening level cutoff, above which concentrations may be unsafe for young children, fetuses, and pregnant people. That’s more protective than the federal Environmental Protection Agency’s threshold for safety, which was 400 parts per million before the Biden Administration lowered it to 200 parts per million in 2024.
If soils have more than this amount, children should not play in them and people should make sure to completely clean any root vegetables growing there. Even if there is a lot of lead in the soil, it doesn’t mean there’s a lot of lead in your body – for the lead to wind up inside you, it means you’re ingesting dust or food or interacting a lot with the soil.
Straightforward solutions can help the situation. For soil you can’t move, the easiest is just to cover the bare dirt with something else – mulch, woodchips, or even grass. Using raised beds or containers with clean soil for gardening creates a barrier between the contaminated soil and the clean soil for plants to grow in. Adding compost to soil can also increase populations of microbes and fungi, which help break down some chemicals in soil. Soaking vegetables in a 10% vinegar solution can take any remaining soil particles.
Take off your shoes when entering your home, and make sure you’re washing hands and your pet’s paws after they are touching the bare dirt. Wet mopping and cleaning areas around the front door can also go a long way in keeping lead particles out.
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