How to Check Your Soil for Toxic Contamination After a Wildfire
- Share via
Wildfire survivors across Los Angeles County are discovering that the most dangerous consequence from a wildfire isn’t always visible.
Lead, arsenic, and other toxic metals could be hiding deep in their soil, contaminating gardens and making the homes and yards they are rushing to rebuild and play in unsafe.
Lead poisoning can lead to damage to the brain and nervous system, as well as digestive, reproductive, and cardiovascular issues, according to the Environmental Protection Agency. Arsenic exposure can cause skin lesions, cancer, cardiovascular disease, and diabetes, and has also been linked to effects on childhood brain development and neurotoxicity, according to the World Health Organization.
Tests conducted after the Eaton and Palisades fires have revealed high levels of both toxic metals in soil surrounding homes, schools, and parks in areas that didn’t burn. Recent data from Los Angeles County and the Pasadena Unified School District show that up to 80% of soil samples from homes downwind of the Eaton Fire exceeded California’s lead safety limit of 80 mg/kg, and nearly half of Pasadena school campuses tested above state safety levels for lead or arsenic, with some samples showing arsenic levels nearly eight times the local reference.
Worried about lead exposure after the Eaton or Palisades wildfires? LA County is offering free blood lead testing for residents. Learn how to get tested at community clinics or local labs.
Federal cleanup crews skipped post-fire soil testing this year, angering local residents and elected officials who are putting pressure on the state and the Federal Emergency Management Agency (FEMA) to pay for testing.
Several school officials and researchers stepped in to take action themselves, as children, gardeners, and construction workers are especially at risk for health problems from these toxic substances.
If you live in a burn zone and are returning to your property, use this guide to understand soil testing and learn where you can get help.
Who Should Test Their Soil
Testing is especially important on properties where children may have direct contact with soil, since lead exposure can cause serious long-term health problems for them.
Consider soil testing if:
- Your home or property was within or downwind of the Eaton, Palisades, or other recent LA wildfires.
- You plan to grow food, let kids or pets play outside, or begin rebuilding.
- You notice ash, dust, or debris from burned buildings or vehicles on your land.
- A school, playground, or park is in or near the burn zone.
How to Get Soil Tested
Los Angeles County residents have a few options for getting their soil tested for toxins.
LA County Eaton Fire Soil Testing Program
Los Angeles County’s Department of Public Health is funding free lead soil testing for homes and yards downwind of the Eaton Fire. Postcards were sent to about 26,000 eligible addresses.Verify your eligibility and sign up online to get more information. The samples will be analyzed by County‑contracted certified labs within 7–10 business days, and you should expect to receive results by email, including soil lead concentration (in mg/kg), along with clear interpretation guidance and next‑step recommendations.
The program runs through December 2025, with potential extension based on demand and results.
USC CLEAN Project
Take advantage of testing done by USC’s Clean Project by collecting a small soil sample of your soil using USC’s detailed PDF guide. Register your sample online and drop it off or mail it to one of several local sites, including Altadena, Pasadena, Santa Monica, and the Palisades.Results are available in about one to three weeks and are mapped anonymously online. These tests are offered at no cost and screen for lead only. They do plan to expand and include other toxins such as PAHs and arsenic.
Private/Certified Lab Testing
If you choose to do private testing, make sure any lab you use is accredited by California’s Environmental Laboratory Accreditation Program (ELAP). You can find accredited labs by searching the California ELAP Certified Laboratories map.Private testing often costs several hundred dollars per site. It can also include a broader range of toxin tests tailored to your requests.
Learn how burn scars increase the risk of flash floods, debris flows, and water contamination, and what homeowners in Los Angeles can do to protect themselves.
How to Collect a Soil Sample
- Wear gloves and a mask to avoid direct contact with contaminated dust.
- Dig 3 to 6 inches deep using a clean towel or shovel at several locations in your yard.
- Mix samples from different spots together for a more accurate average.
- Seal it in a clean container or bag and label it with the location and date.
- Follow instructions from your testing provider for shipping or drop-off.
Collecting samples from multiple areas of lawns, gardens, play areas gives a more complete sense of the risks you might face. For larger or high-use spaces, such as a school field, multiple composite samples may be needed.
What Your Test Results Mean
If lead is above 80 mg/kg or arsenic is above 12 mg/kg the soil is considered unsafe, especially for children. If your report shows soil toxins above state or county safety standards, here’s what to do:
- Limit contact immediately and cover bare soil with mulch, tarps, or other barriers to keep dust down.
- Restrict access for kids and pets.
- Contact LA County Environmental Health at (888) 700-9995 for remediation advice or eligibility for free cleanup programs.
- Don’t garden, dig, or disturb contaminated soil until you have a remediation plan.
For less severe contamination, alternatives to soil removal may include capping soil with new clean dirt, building raised beds, or using organic amendments that can help bind toxins and reduce exposure.
Even if your home didn’t burn, wildfire smoke and ash can pose serious health risks. Use this guide to learn how to decide when it’s safe to clean your home yourself and when to hire a professional restoration crew.
Need More Help?
Grow Real Organic and similar groups offer practical help for residents who want to restore their gardens safely and sustainably with some DIY practices. Their services include soil consultations, testing, and organic gardening classes focused on rebuilding soil health after fire. They will share recommendations for using compost, biochar, and plant-based remediation methods that can help stabilize or break down toxins while supporting long-term soil recovery.
While some services may have costs, many nonprofit workshops and community classes are available across the region.
Take advantage of the testing resources now available, ask questions, and reach out for expert help if you need it. If you’re returning to a burned property or working in a neighborhood affected by wildfire, don’t assume the soil is safe just because cleanup crews have moved on.
Anyone who has developed breathing problems, suspects they ingested contaminated ash or wildfire smoke, or believes they may have come in contact with contaminated soil or ash, should undergo free blood testing for lead poisoning to get ahead of future health issues.
MORE FROM THE HUB: REBUILDING LA
