The Altadena area has a higher percentage of soil samples with lead levels above healthy thresholds than the Pacific Palisades area, months after both communities were ravaged by brush fires.
The Los Angeles County Department of Public Health shared its final findings of soil testing in the fire-affected communities. It was also discovered that two Palisades Fire areas had localized chemical impacts to soil above what’s considered healthy. However, there wasn’t evidence of widespread contamination for fire-related materials.
In Altadena, 10 of the 23 sampling grids that had intact homes had higher levels of lead than the healthy threshold. The county believes the source of the lead in the fire is a result of burning homes that had lead-based paint, which was common before 1979. More than 70% of homes in Altadena were built before then.
As for Pacific Palisades, the county didn’t find any large-scale fire-related soil impacts, including for lead. One isolated area had cadmium and thallium in its sample, while another had arsenic and polyaromatic hydrocarbons (PAHs). It’s not known if the materials were a result of the fire.
Soil samples were collected from burn areas between Feb. 18 to March 26 and measured for levels of harmful substances, including heavy metals, polyaromatic hydrocarbons (PAHs) and dioxins/furans. They were then compared to the state’s residential soil screening level thresholds for reference.
The county noted that “because there are many potential sources of lead in soil in the Los Angeles area, additional assessments may help understand how much of the lead found in the samples came from the 2025 wildfires versus other sources.”
The report also showed there was a significant reduction in potential health risk in fire-affected areas that had soil and debris removal done by the U.S. Army Corps of Engineers. The county warned that despite that optimistic finding, there could still be areas where harmful materials in soil could surpass residential screening levels.
To read the full report, click here.