Faced with more than 370,000 signatures supporting a porn condom-use ordinance, Los Angeles County supervisors seem likely to put such a measure on the ballot this fall.

For years, Los Angeles County supervisors ducked any responsibility for making sure that adult film actors wear condoms to guard against HIV  infection while on the job.

But faced with the successful collection of more than 370,000 signatures supporting such an ordinance, supervisors for the first time Tuesday reluctantly girded for the likelihood that the nation’s most populous county — and center of the American porn industry — may very well vote to approve such a measure at the ballot box this November.

Officials, however, seemed skeptical that it would prove effective. Supervisor Zev Yaroslavsky, whose sprawling district includes the San Fernando Valley, where many porn films are produced, said he was uncertain how underground porn shoots that don’t bother to ask for permits would be monitored for condom use.

Said Yaroslavsky: Inspectors will not “be able to find every garage in the county of Los Angeles where the filming takes place.”

“Having said that, signatures have been gathered and the county registrar certified it and I do believe that the voters have a right to vote on this,” the supervisor said. “But I do think that there’s going to have to be a lot of work done … to create a path forward for credible enforcement of the law.”

Despite the skepticism, it was a remarkable change in tone for the five-term supervisor, who two years ago adamantly asserted that the state, not the county, bears the primary responsibility for mandating condom use by porn stars. Back then, he suggested that it was all but impossible for the county to police condom use and said that what AIDS activists wanted was akin to running “around like chickens without a head looking in every garage in L.A. County see if there’s a motion picture being filmed.”

No supervisors spoke up Tuesday against putting the initiative on the ballot or indicated that they opposed the ordinance.

On the other side of the podium was Michael Weinstein, president of the L.A.-based AIDS Healthcare Foundation, who seemed confident of victory at the polls and exuberant at finally being able to force the supervisors to pay closer attention to the issue.

He urged the officials to “recognize the will of the people.” And, he added, as leader of a provider of AIDS healthcare around the world, “I feel a personal responsibility that this industry, which is a scofflaw, operates in my backyard and not only is endangering these young people who are in the industry, but it’s sending a terrible message to the world that the only kind of sex that’s hot is unsafe,” Weinstein said.

The porn industry has become a financial success in California after a 1988 state Supreme Court decision that porn producers could not be prosecuted under anti-prostitution laws.

But the industry has come under scrutiny over the years with news coverage of performers who say they became infected with HIV on the job. The most recent publicized infection was the case of Derrick Burts in 2010.

The industry has disputed that Burts was infected on the job but has not produced evidence backing up its claim.

A countywide vote on requiring condoms for porn performers would be the first in the nation. The Los Angeles City Council opted to approve a similar porn condom ordinance in order to avoid a citywide election in June after the gathering of more than 70,000 signatures at the city level.

The AIDS group also released a poll of more than 1,000 likely voters in April, in which 63% of respondents said they would vote in favor of a condom requirement.

How the porn industry will react to a countywide measure is the next big question. The industry did not take any significant action to lobby against the city measure, but a spokesperson criticized it as “government overreach.”

Jeffrey J. Douglas, chairman of the board of the adult film lobby group Free Speech Coalition, said the industry has not made any formal decision but is likely to campaign against the condom measure and possibly sue the county.

He argued that the county measure may violate the 1st Amendment’s guarantee of free speech by “requiring a specific message to be contained in a film.” And he argued that the county initiative could be preempted by state law.

AIDS activists have countered that the state has said local governments have the authority to require condom use on the set.

Weinstein, for his part, said he was eager for a full campaign with the porn industry.

“If we have ads brought to you by Larry Flynt  and other pornographers, we would be thrilled,” Weinstein said. “It’s not hard to figure out that people don’t hold pornographers in high esteem.”

Dr. Jonathan Fielding, the county’s director of public health, who has also rebuffed AIDS activists’ desire to regulate condom use on the county level in the past, expressed his concerns “about how difficult it may be to enforce this should it become law.”

Whitney Engeran-Cordova, senior director of the AIDS group’s public health division, said major porn studios that do get filming permits would eventually feel pressure to comply with the law if they want to keep their insurance.

The supervisors could vote as soon as July 24 to place the condom measure on the ballot.