LOS ANGELES — Health officials have tested the air and deemed it safe. Yes, the awful smell from a huge natural gas leak near the Porter Ranch neighborhood may cause vomiting, nosebleeds and other short-term symptoms, they say, but they have assured residents that it does not pose long-term health risks.
Many people here, however, simply do not buy it. And now they look warily toward Flint, Mich., where the switch to a new water supply, which state officials insisted for months was safe, has left children with high levels of lead in their blood.
With Flint as a potent warning, confidence in public agencies has collapsed here after the gas leak. Unconvinced by health department reassurances, residents have turned for guidance to lawyers who are spearheading lawsuits. And the eroding public trust now poses its own threat to the community: Of the thousands of families who have fled the area, many say they are not sure when they will feel safe returning, if ever.
“Do we believe the health department? No,” said David Balen, a member of Porter Ranch’s neighborhood council. “The gas company? No. If the gas company called tomorrow and offered to buy our house, I’d do it in a heartbeat.”
Public trust has been a frequent casualty of environmental disasters. Hinkley, Calif., has slowly turned into a ghost town in the two decades since residents won a $333 million settlement from Pacific Gas & Electric for contaminating the water with chromium 6, a cancer-causing heavy metal, as fears about the water have persisted. And two years after a chemical spill in Charleston, W.Va., some residents still will not drink the tap water.
No consistently high levels of heavy metals or known carcinogens have been found in Porter Ranch, a wealthy master-planned neighborhood in the hills at the edge of the San Fernando Valley.
Still, health officials have found it nearly impossible to break through the public’s skepticism.
Last week, the Los Angeles Department of Public Health announced that air quality monitoring would be stepped up even further. And officials reiterated that, based on the current data, they saw no indication that the gas leak posed long-term health risks.
The gas well, which began spewing methane and other chemicals in late October, will not be plugged until late February at the earliest, according to the Southern California Gas Company, which owns the natural gas storage field where the leaking well is.
Angelo J. Bellomo, the health department’s deputy director for health protection, said the levels of benzene, a known carcinogen found in natural gas, “have generally been consistent with what we find throughout the L.A. basin.”
Mr. Bellomo acknowledged that it was “a difficult message to get out.” The public, he said, has “heard government reassure them before, only to find that government flip-flops on what they’re saying.”
Although benzene levels have largely been normal, they were elevated for a handful of days late last year, and some outside scientists questioned whether other chemicals whose effects are less known could be causing some symptoms.
But little of the public skepticism in Porter Ranch is based on scientific measurements. More often, residents cited a broader distrust of the government, or the conclusion that breathing in gas all day simply could not be healthy.
Johnny Mikaili, 19, said he and his family were still waiting for the gas company to relocate them. In the meantime, his 11-year-old brother has developed a series of respiratory problems, which Mr. Mikaili said were caused by the gas leak, regardless of what medical officials or anyone else might say.
“I mean, use common sense, man,” he said. “It’s natural gas in the air, being pumped out of the earth from a thousand feet down, and now you’re inhaling it.”
And even as health officials have tried to calm nerves, some elected officials have emphasized the absence of scientific studies on some chemicals. Two big-name environmental health advocates, Erin Brockovich and Robert F. Kennedy Jr., have also held community meetings in which they have recruited residents to sign onto lawsuits against the gas company.
“People have lost faith in the agencies that are supposed to protect them — look what happened in Flint,” said Mr. Kennedy, an environmental lawyer who was also involved in the case against BP over the oil spill in the Gulf of Mexico in 2010.
Speaking of Porter Ranch, he said, “They see the health department as a sock puppet for the industry it’s supposed to regulate.”
More than a dozen lawsuits have been filed against the gas company, and more than 2,000 families have left the area, with food and lodging paid for by the Southern California Gas Company. But the lawsuits have divided the community between those who have stayed in the area despite the smell — and who trust the science about the safety of remaining there — and those who believe that the area is unsafe.
Bryan Bernhard, 36, said some of his neighbors who had filed for relocation were still at home most of the time, and were eating at a hotel only for the free meals.
“It’s really a big money grab — I don’t think the smell is that bad,” he said. “The community’s really turning on itself, and it’s kind of sad. People don’t realize the lawyers are going to get most of the money.”
But he added that if his home were in an area where the smell of gas was constant, he would probably relocate.
Many of those who have relocated said they did go home sometimes — to check mail, to make sure their homes have not been burglarized or on occasion to spend a night in their own beds.
Convinced that many families will not come back as long as the gas storage field remains active, a group of residents wants to try to shut the field down entirely; many of the wells date to the 1940s.
Naheed Khaja, 61, said she wanted to move back once the leak was stopped. But asked if she trusted the health department’s assurances, she said, “No.”
Ms. Khaja, who works in real estate, said the value of some homes, many of which were worth nearly $1 million, had fallen by as much as 25 percent since the leak.
“I’d love to come back once things get back to normal,” she said. But she added, “Nobody knows the long-term effects. I am skeptical.”
Ciana Tallas, 37, a teacher who moved with her daughter out of the area, agreed. “I’m not thinking about a permanent relocation,” she said. But she added that she was not reassured by the health department. “How do they know?”
Ms. Brockovich, whose work exposing the chemical contamination in Hinkley inspired a 2000 movie named after her, said that in every community she had worked in, she had seen people who did not want to believe that anything serious was wrong.
“We don’t want to create a great deal of fear — it already exists,” Ms. Brockovich said. “But when you have 5,000 people all experiencing the same symptoms, why would you continue to believe what Southern California Gas says, that it can’t harm you?”