LOS ANGELES (AP) — Homes located near a gas well blowout that spewed the nation's largest-known release of methane had higher levels of toxic metals that could have caused symptoms Los Angeles residents have suffered from for months, public health officials said.
Tests found barium, manganese and vanadium more frequently and in higher concentrations in dust in homes located near the Aliso Canyon gas storage facility, the Los Angeles County Department of Public Health said Friday.
The contaminants could be responsible for eye, nose, throat and skin irritation, but are not expected to cause long-term problems, the report said.
Some 8,000 families moved out of their San Fernando Valley homes after the gas well blowout in October, with many people complaining of persistent headaches, nausea and nosebleeds. Even after Southern California Gas Co. permanently sealed the well nearly four months later, a survey found a majority of homes continued to report health problems.
Health officials initially attributed symptoms to the stinky odorant added to make the gas detectable, but ailments such as rashes and bloody noses were not known to be caused by that chemical.
"It's really interesting to see all these metals come out to confirm there's probably more than one reason people have become sick," said Alexandra Nagy, an environmental activist who wants the facility shut down.
The unusual patterns of metals found appear to have come from the well where gas is stored in a vacant oil field deep underground, said Michael Jerrett, chairman of the Environmental Health Sciences Department at the University of California, Los Angeles.
Some of the metals are trace elements of oil, and barium was an ingredient in the muddy brine used in unsuccessful attempts to plug the high-pressure leak, said Jerrett, who performed environmental testing in Porter Ranch homes.
During attempts to plug the well, an oily mist was sprayed into the air and residents received robocalls telling them to stay inside.
"In a sense, we have a fingerprint that there was something that intruded into a large portion of houses related to hydrocarbons," Jerrett said, though he couldn't say for sure that the well was the source. "Barium would be the most direct link to the well leak itself."
Health officials suggested residents take several measures to thoroughly clean and ventilate homes.
SoCalGas, which expects the leak to cost $665 million, mostly for relocation costs, said the report showed it's safe to return home. Thousands of families remain uprooted.
"It is time for the residents who chose to remain relocated to exit the relocation program, and for the community as a whole to return to normal," the company said in a statement.
Jerrett said he's going to recommend that several homes where elevated levels of cancer-causing benzene and hexane, a neurotoxin, be tested further.
The report said it's possible other contaminants are present in homes and ambient air, noting that the facility is the single-largest emitter of formaldehyde in the region.
It also said methane levels continue to be higher than expected and could be coming from another source.