Hans Nansen of Carlsbad sometimes suggests to friends that they go out to a casino, but he gets an immediate objection.

“We want to go out there, but ‚Oh, God, the smoke,‘ ” he said. “I can only stand it so long.”

Thirteen years after California banned smoking in most workplaces, there’s one public place where people regularly light up: tribal casinos.

A survey of more than 1,700 Southern California gamblers released last week by J.D. Power and Associates found that 85 percent would prefer a nonsmoking environment at their casinos.

It’s an opportunity for casinos in difficult economic times, said Sam Thanawalla, who oversees hospitality and travel studies for the consumer research organization.

California regulations don’t apply on Indian land, and only one tribe, the Hoopa north of San Francisco, has decided to make its casino smoke-free.

Reflecting customer demand, some local casinos are expanding their nonsmoking space.

The Sycuan Resort and Casino near El Cajon recently converted a quarter of its gaming floor into a nonsmoking wing with its own entrance, cashier cage and restrooms, marketed with the slogan “Play Smoke Free.”

“Customers requested it,” casino spokesman Mike Tabor said.

The Valley View Casino in Valley Center added a glassed-in nonsmoking area during an expansion last year and is already looking at enlarging it.

Viejas Casino & Turf Club in Alpine said more than half its casino is nonsmoking, though there are no barriers between smoking and nonsmoking areas.

Nansen said that doesn’t do anything because smoke easily drifts inside a big room.

Nonsmoking sections that aren’t physically separated are also frustrating for smokers, said Joan Young of San Diego, who likes to smoke while gambling.

“All of a sudden you entered nonsmoking area and you have a cigarette in your hand,” said Young, an administrative assistant. “That’s just bad design.”

Young said it’s appropriate that smokers are still welcome in casinos.

“Aren’t we supposed to be land of the free?” she said. “We’re not trying to go into day care centers and light up.”

Smoking has long been on the decline in California. In 1984, about 25 percent of the state’s adults said they smoked; by 2006, that had dropped to 13.3 percent.

So it follows that casinos would be affected by the trend.

“Our customers are starting to tell us they’re really interested in having a nonsmoking area,” said Rick Salinas, general manager at Barona.

Smoking is banned in 15 percent of the casino, and workers kick the ventilation system into high gear when sensors detect too much smoke.

Although Salinas sees cigarette-free areas growing, he doesn’t expect smoking to go away from casinos anytime soon.

But that’s already happening elsewhere, with mixed results.

Commercial gambling halls in New York state continued raking in the bucks when smoking was banned in 2005, but casinos in Atlantic City have long fought a ban – which is now expected for October, when smokers will be relegated to glassed-in lounges.

In Illinois, casinos had to send smokers outdoors beginning this year, and business is hurting. “People are spending less time actually gambling,” said Tom Swoik, who heads a casino trade group.

Revenues are down 17 percent because people are heading to Indiana, where casinos are exempt from smoking bans, Swoik said. “We’ve lost market share.”

In Nevada, voters approved a smoking ban in 2006, but all except the smallest casinos are exempt, so Las Vegas gamblers may still puff away. Some casinos there have established small nonsmoking areas.

A worldwide survey of smoking studies released Tuesday by a University of California San Diego cancer researcher and others found that smoke-free policies lead people to smoke less.

It doesn’t have to hurt casino business, said the researcher, John Pierce of the Moores UCSD Cancer Center.

He said 40 percent of nonsmoking gamblers in California told researchers they would gamble more if casinos were smoke-free, and 70 percent of smokers would continue to gamble at the same pace even if they were forbidden from lighting up in a casino.

Smoking and gambling have long been linked in our minds partly because they’ve gone through a similar evolution, from sin to vice to entertainment, said Dr. Timothy Fong, who studies addiction at the University of California Los Angeles.

Some gamblers smoke to deal with the stress of risking their money, but studies suggest they don’t gamble more. Smoking doesn’t lead to more risk-taking or longer gambling sessions in the way that alcohol does, Fong said. Casino operators take a pragmatic view.

Bob Scheid, a spokesman for Viejas, said the casino has studied the issue and found that people like to smoke while they gamble.

“We’re probably never going to be 100 percent smoke-free,” he said.