There's no telling when the nasty smell in Carson will be gone, county officials say

Three weeks after a foul smell began plaguing Carson residents, Los Angeles County officials say they can't predict when it will dissipate.

Some residents are so fed up that they have filed a lawsuit alleging a warehouse fire caused a buildup of decaying vegetation in the Dominguez Channel, leading to the smell.

After crews finally began spraying a biodegradable neutralizer last Friday, officials predicted the odor would go away by the middle of this week. Then, they pushed it back to the weekend.

Now, they are not committing to any date at all, citing variations in individual sensitivity to the smell that has been likened to rotten eggs, vomit, body odor or farts.

Levels of hydrogen sulfide, the gas that causes the smell, have decreased significantly since the spraying started, L.A. County Public Works Department Director Mark Pestrella said at a news conference Friday.

The odor should be much weaker by the weekend, Pestrella said, without setting an end date.

"I can’t predict when the event will be over for individuals, because each individual has a different sensitivity to hydrogen sulfide gas," he said.

Public health recommendations have fluctuated too.

Initially, residents were told to close their windows. Health officials said hydrogen sulfide levels were too low to cause long-term problems, though headaches and nausea could result.

But earlier this week, they advised residents not to engage in prolonged outdoor exercise between 9 p.m. and 8 a.m.

Carson Mayor Lula Davis-Holmes said Friday that the failure to provide an end date for the odor is unacceptable.

She also underlined a complaint made by some residents — that a wealthier, whiter community would have received help sooner.

“We should not have to wait this long for a solution for an odor that's from decaying vegetation in a channel," she said. "Had it been in another city, a more affluent city, I think it would have happened a little faster.”

Carson is 37% Latino, 27% Asian, 24% Black and 7% white, with a median household income of about $82,000, according to the U.S. census.

On Friday afternoon, Carson city officials said they planned to ratify a local emergency proclamation and would demand that the county, state and federal government do the same.

Rep. Nanette Barragán (D-San Pedro) has asked Gov. Gavin Newsom to declare a state of emergency.

City and county officials have instituted reimbursement programs for air purifiers and hotel rooms. But getting the money could take weeks.

Pestrella said Friday that the county has booked hotel rooms for residents to escape from the smell, with 26 households taking advantage of the program so far.

Residents who can't afford air purifiers can pick up a free one at Victoria Regional Community Park. he said.

Hydrogen sulfide levels as high as 1,000 parts per billion were recorded near the Dominguez Channel earlier this month by the South Coast Air Quality Management District.

A much lower amount — about 10 parts per billion — is enough to cause adverse health effects, said Jill Johnston, an assistant professor of environmental health at USC.

Hydrogen sulfide is a toxin, and there is little research on the effects of long-term exposure, she said.