Alarming lead levels appear on surfaces around Eaton Fire burn area

ALTADENA, Calif. (KABC) -- Researchers at Caltech have been collecting samples from dozens of homes in and around Altadena since the Eaton Fire burned hundreds of homes in the area in January.

The results of 52 tests found an alarming rate of lead concentration on indoor surfaces: more than half had lead levels on them higher than at least the EPA limit.

"For children, there is no safe level of lead," said Francois Tissot, Caltech professor of geochemistry.

The equipment humming in Tissot's lab is being used to test the samples that were collected in and around the Eaton burn zone. When Eyewitness News toured Caltech's facilities, test tubes were crushing samples of dust and ash collected from windowsills.

And what Tissot found concerns him.

"If you were in the fire plume - especially in Pasadena nearby, the fire side - there will be lead and heavy metals in the house," Tissot said. "For sure."

The EPA lead limit on windowsills is 40 micrograms of lead per square foot. One sample Tissot collected had 6,000 micrograms of lead per square foot.

As for that home, Tissot said: "This is definitely a very dangerous place to be and no one should be in the house until remediation happened."

In good news, Caltech found that lead levels on windowsills dropped dramatically once they were cleaned -- 90% of cleaned windowsills tested had levels within EPA limits.

But in a few cases, cleaning didn't eliminate lead contamination.

"You cannot just assume that because you have cleaned, it is clean," Tissot said.

For professor Tissot, this research is deeply personal. His home in Altadena has been severely damaged by the fires. Every single one of his neighbors' homes was completely burned to the ground.

"The house is unlivable, and it may be unlivable forever," Tissot said.

It's that personal connection driving him to work side-by-side his colleagues like Paul Wennberg. He's an air quality expert at Caltech who is tracking 25 air monitors in and around the Eaton burn zone.

"Generally, air quality across the world and in Los Angeles, is a major impact on human health," said Wennberg, Caltech professor of environmental science.

You can check the dust levels those 25 monitors are detecting on Caltech's website here.

The researchers are finding that dust levels tend to spike in the overnight hours, which could be ash created by the fire blowing down from the mountains.

Next, they hope to investigate what, if any, toxins may be hiding in that dust.