ATLANTIC CITY, N.J. — Len Lombardo, 74 and retired, rests his cigarette against a black plastic ashtray as he pushes a $5 button on a high-limit slot machine at the Resorts Casino Hotel in Atlantic City, N.J. Nearby, a 62-year-old Pennsylvania woman on a winning streak takes a drag from a Newport, as does her sister sitting at the machine to her right.

The smell of burning cigarettes and smoldering cigars hangs in the air, a jarring throwback to a time before 2006, when indoor smoking was outlawed virtually everywhere else in the state.

Across the country, the hazy scene has become increasingly rare since pandemic shutdowns led many casinos to rethink employee and customer safety and long-term business models.

And in Atlantic City, the most prominent U.S. gambling hub outside of Nevada, an employee-led push to ban smoking on casino floors has gathered momentum and clout, representing a potentially critical moment for the industry nationwide.

“A lot of eyes are on Atlantic City,” said Cynthia Hallett, president and chief executive of Americans for Nonsmokers’ Rights, a nonprofit that over four decades has pressed for smoke-free casinos, airplanes and bars.

Twenty states, including New York and Massachusetts, already ban smoking in casinos, as have many Native American-run gambling hubs. Mohegan Sun and Foxwoods in Connecticut and the four casinos operated by the Navajo Nation, the country’s largest tribe, are now smoke-free. Even in states that allow smoking, like Pennsylvania, some leading casino operators have opted to remain smoke-free since the coronavirus pandemic, leaving Atlantic City as the last large refuge for smokers in the Northeast.

“The old paradigm used to be: Well, smokers play more,” said John Cirrincione, the chief executive of the Santa Ana Star Casino Hotel in New Mexico, who eliminated smoking at his facility after the onset of the pandemic. “But that’s years of excluding a large part of the public who don’t want to come into a smoky casino.”

“I’m a little guy out in the middle of a desert,” he added. “I’m not going to set the trend, but I don’t have to accept it. If Atlantic City made the move, it would definitely push nonsmoking forward.”

Mark Giannantonio, the chief executive of Resorts and the new president of the Casino Association of New Jersey, said he recognized that ending smoking was most likely a matter of when, not if. But he opposes the effort to do so right now.

“There is a time for this, at some point,” Mr. Giannantonio said. “It’s just not the right time.”

He pointed to what he sees as several economic threats to New Jersey’s gambling industry: the lingering effects of the pandemic; the risk of a prolonged recession; and the three new casinos that could be built in or near New York City. “The economics are real,” he said.

But employees who say they fear for their health in a workplace filled with potentially deadly secondhand smoke consider the policy craven, even immoral.

“They know all the harmful effects of smoking,” Roger Colao, a craps dealer at Resorts, said on a recent morning between rolls. “Yet they sell us out for money.”

Nicole Vitola, a dealer at Atlantic City’s Borgata casino, worked while pregnant with both her children, who are now 21 and 16. When smoking returned to Atlantic City in July 2021 after a yearlong Covid-related moratorium, she was irate.

“How do you say, ‘We’re going to protect you. We’re going to care for you,’ when it comes to Covid,” said Ms. Vitola, 48, who wears an N-95 mask at work to block smoke. “And then as soon as the pandemic is over, the cigarettes are back, and they just forget about us and whether we get cancer.”

A group Ms. Vitola helped to found last summer, Casino Employees Against Smoking Effects, or CEASE, now has chapters in Pennsylvania and Rhode Island. Members traveled to Las Vegas last month to spotlight the health risks associated with breathing secondhand smoke, which the Centers for Disease Control and Prevention says can cause heart disease, lung cancer and stroke.

“Our gripe is not with the casinos,” said Lamont White, who has worked as a card dealer at various Atlantic City casinos since 1985. “Our gripe is with the state. The state protects everybody else — except people who work in casinos.”

The New Jersey Smoke-Free Air Act of 2006 carved out exceptions for casinos, simulcasting facilities, cigar bars and tobacco shops. Each of Atlantic City’s nine casinos now designates roughly a quarter of their gambling floors for smokers, meaning that smoking and nonsmoking games are often only feet apart.

A bill to ban casino smoking altogether in New Jersey has gathered enough sponsors to all but guarantee passage if it were to reach a vote in the Assembly and Senate; the governor has said he would sign it into law if it reached his desk.

“There are people who are getting sick — some are dying,” said State Senator Joseph F. Vitale, a Democrat who leads the Senate’s health committee and is a prime sponsor of the bill to expand the smoke-free air act to include casinos. “It’s really prehistoric, and immoral.”

Still, the bill has stalled, just as it did in prior legislative sessions. The Democratic leader of the State Senate, Nicholas Scutari, said in July that he expected the legislation to eventually pass, but said there were “economic things” and “other items” at work. Democrats are clinging to a tenuous hold on political power in parts of southern New Jersey, where many casino and hotel workers live, and Mr. White said he was told lawmakers needed to see what happened in upcoming elections before the legislation could advance. Mr. Scutari indicated in a text message that he would have no additional comment.

Mr. Giannantonio, citing a report prepared at the request of the casino industry, estimated that a smoking ban would lead to a roughly 10 percent to 11 percent decline in revenue, a dip that he said could lead to potentially 2,500 fewer jobs. Total casino employment stands at roughly 22,000, down nearly 5,000 from a prepandemic snapshot in December 2019.

The number of smokers in the United States has shrunk by nearly half over the past two decades, to 12.5 percent of adults in 2020, from 23.3 percent in 2000, according to the C.D.C. Yet smokers make up about 21 percent of visitors to Atlantic City and an outsize portion of the casino’s revenue, 32 percent, according to Mr. Giannantonio and an analysis by Spectrum Gaming Group.

If smoking were banned, some gamblers would be likely to choose to travel to casinos in Pennsylvania where it remains legal, Mr. Giannantonio said. Smokers who need to leave a game to have a cigarette outdoors would also be expected to spend less time playing. This would lead them to lose an estimated $16.62 less than a nonsmoker over a two-hour period, according to the Spectrum report.

The union that represents casino card dealers, who often stand feet away from smokers as they work, supports the proposed smoking ban. A larger union, which represents most other casino and hotel employees, opposes it.

“Anyone who thinks it’s not going to affect the revenue is either being dishonest or naïve,” said Bob McDevitt, president of Local 54 of the Unite Here casino workers union. “It’s going to cost jobs.”

The mayor of Atlantic City, Marty Small, also opposes a ban on smoking; the City Council, however, supports it.

A separate analysis by a Las Vegas-based consulting group, C3 Gaming, concluded that the effect on revenue and jobs would be far less drastic. Andrew M. Klebanow, of C3 Gaming, said the Spectrum report was based largely on outdated data.

In Bensalem, Pa., just north of Philadelphia, the Parx Casino pulls in more revenue from slots than any of its competitors statewide. Officials there decided not to restore smoking when it reopened after a pandemic shutdown, mainly out of concern for employees’ health.

“It’s been great for our team,” said Eric Hausler, president and chief executive of Greenwood Racing Inc., which owns Parx. “It’s less wear and tear on the building.”

Overall revenue is down but still robust, he said.

Lisa Mell, 62, said she came to Atlantic City about twice a month. She said she associated smoking and gambling with relaxation and enjoyed doing both at the same time.

“It goes hand in hand. Smoking and gambling,” Ms. Mell, who lives about 20 miles away in Somers Point, N.J., said as she played a slot machine at Resorts on a recent weekday morning. If smoking were banned, she said, “it wouldn’t be as much fun.”

Many people said they preferred to be able to smoke while playing to avoid losing a potential jackpot while taking a break outside.

“It’s that next spin,” said Mike Coover, 35, a plumber at the Tropicana who was gambling at Resorts and said he smoked about a pack of cigarettes a day. He said he never minded leaving a machine to take a smoking break during the yearlong ban, but said it was common for gamblers to be superstitious about walking away and missing a win. “You always think it’s that next spin,” he said.

Mr. Lombardo said he made fewer trips to Atlantic City when smoking on the casino floor was forbidden, in part because he could not smoke. And when he does come to the casinos, he prefers to sit in the smoking sections.

But he said he would not mind a ban that much.

“They’d do me a favor,” he said. “Actually — probably a lot healthier.”