After months of questions in the aftermath of the Eaton and Palisades fires, the Los Angeles County Department of Public Health has finally shared preliminary results from soil testing in and around the burn areas. The publicly available data are still somewhat vague — but they do show concerning levels of lead on properties downwind of the Eaton fire, as well as isolated “hot spots” of contamination in the Palisades.

The results were revealed during a virtual community meeting Thursday evening and offer the first glimpse at the lasting fallout from January’s devastating firestorm.

Roux Associates, a private testing firm hired by the county, collected samples from 780 properties in both burn zones over four weeks from mid-February to mid-March. It analyzed those samples for 14 toxic substances commonly found in the wake of wildfires, including heavy metals such as arsenic and lead; polyaromatic hydrocarbons such as anthracene and napthalene; and dioxins.

The first batch of results — the county said more data are forthcoming — focused on intact properties that were left standing after the fire, and found that as much as 80% of soil samples collected downwind of the Eaton burn scar had levels above the state health standard of 80 milligrams of lead per kilogram of soil. Results for parcels of land with damaged and destroyed properties are still pending.

The findings around lead are “really where we did see something that stood out,” said Adam Love, Roux’s vice president and principal scientist. “We saw much higher percentages of exceedance of the screening levels in the areas that were immediately downwind of where the main houses burned in the Eaton fire.”

Around 36% of parcels within the Eaton burn scar exceeded the state limit for lead, the results show. Far more, 47%, exceeded it in areas just beyond that boundary. In the area southwest of Eaton fire zone, between 70% and 80% exceeded the lead levels.

The findings revealed Thursday did not include specific values or parcel-level results for the still-intact homes, but they did show the share of properties tested in the area that exceeded California’s health limit for lead and other chemicals. Virtually all tested parcels were homes, although a few of those tested outside the burn area were public spaces, Love said.

Love noted that it is typical for urban areas to have higher levels of lead than the overall state limit — especially places near highways where cars used to burn leaded gasoline. What’s more, Altadena was home to a large number of buildings that probably contained lead paint, with one report from CalTech indicating that more than 90% of houses in the area were built prior to 1975, three years before the paint was banned.

But the high number of properties on which lead was detected at levels exceeding health standards suggests that decades-old paint alone may not fully account for the toxicity, Love said. At least some of that is likely to have come from the fire and its smoke.

Lead is a heavy metal that is linked to serious health problems including damage to the brain and nervous system, as well as digestive, reproductive and cardiovascular issues, according to the Environmental Protection Agency. Children, elderly and pregnant people are particularly sensitive to the chemical.

Exceeding screening thresholds does not automatically mean cleanup is necessary, but rather that additional evaluation should be considered, county officials said.

On the other side of the county, the Palisades fire burn zone generally fared better as there was no evidence of widespread contamination, officials said.

However, the Palisades tests did reveal what Love called isolated “hot spots” of heavy metals and polyaromatic hydrocarbons.

Among those heavy metals was arsenic, a known carcinogen. The worst results were found on properties just outside the fire boundary, where nearly 26% of the parcels showed arsenic levels above 12 milligrams per kilogram, the “background level” established by Roux and based on a high-end estimate of what naturally occurs in Southern California soil.

“Whereas with Eaton, the arsenic was evenly distributed, in Palisades, we see sort of a hot spot up in the … northeast section of the Palisades area,” Love said.

The source of the contaminants in those areas was not immediately clear, as they are not consistent with fire-related smoke plumes, he said.

Nichole Quick, chief medical adviser with the L.A. County Department of Public Health, said officials are requesting federal and state partners to help further assess the Palisades hot spots, and are coordinating with the county to explore options for more targeted lead testing in affected areas downwind of the Eaton fire.

All of this follows reports from The Times that federal officials opted to break from their nearly two-decade tradition of testing soil on destroyed properties that have been cleaned by the U.S. Army Corps of Engineers. The Army Corps in the past would first scrape 6 inches of topsoil, and then test the ground underneath; if those tests revealed toxins still on the property, it would scrape further.

Indeed, in the past, such testing has proved essential. After the devastating Camp fire in Paradise in 2018, soil testing of 12,500 properties revealed that nearly one-third still contained dangerous levels of contaminants even after the first 6 inches of topsoil were scraped by federal crews.

Crews had to return to some of those properties as many as five times to remove more soil before they were deemed safe and clear.

In this case, however, the agency that typically oversees that work — the Federal Emergency Management Agency — instead said removing 6 inches without further testing will be enough, citing at various times costs, efficiency and policy changes as their justification.

L.A. County ordered the testing from Roux in lieu of that federal testing. So far, the county has announced results only from standing homes, which are not eligible for cleanup from the Army Corps of Engineers.

The results of soil testing from scraped properties are still pending, Love said. A final report and analysis will be available in May.

Many residents and public officials were frustrated with FEMA’s decision to abstain from testing in the wake of the fires, with the state’s Office of Emergency Services director Nancy Ward calling on the federal agency to reconsider.

“Without adequate soil testing, contaminants caused by the fire can remain undetected, posing risks to returning residents, construction workers, and the environment,” Ward wrote in a February letter to the agency. “Failing to identify and remediate these fire-related contaminants may expose individuals to residual substances during rebuilding efforts and potentially jeopardize groundwater and surface water quality.”

Officials in Los Angeles said residents with concerns about their specific properties may want to consult environmental professionals for evaluation.

“In all areas with ongoing fire debris, residents are reminded to take precautions to not inhale, ingest or come into contact with ash, soot, and/or fire debris by using appropriate personal protective equipment,” the Department of Public Health wrote in a summary report of its findings. “Additionally, community members are encouraged to review the soil sampling results and consider taking appropriate precautions if your home is in one of the areas where soil sample screening thresholds have been exceeded.”

The county is also offering free lead blood-level screening for anyone impacted by the fires and concerned about exposure.