PORTLAND — Health inspectors will start sniffing the air for traces of smoke in city restaurants this week, as a citywide smoking ban overwhelmingly approved by residents six months ago takes effect.

City officials have been giving restaurateurs time to learn more about the ordinance, which passed in November. Starting Saturday, they’ll have to be in compliance.

“We’re going to follow up on complaints from citizens and also check during our food service inspections for evidence that people may be smoking,” said Mark Adelson, Portland’s director of housing and neighborhood services.

The city ordinance bans smoking in restaurants without separate, ventilated rooms and affects any establishment where food sales make up at least 60 percent of receipts. City officials say that formula will allow smoking in 35 of 274 restaurant-bars in Portland.

A statewide ban on smoking in restaurants, approved in March, takes effect 90 days after the Legislature adjourns. Adjournment is set for May 28 but could be delayed.

“Some [restaurant owners] are still angry about it, but a lot have adjusted,” said Jeannine Larochelle, owner of the Dry Dock Restaurant and Tavern. “I just made my place no smoking. I had to get on with it.”

Some restaurant owners are still fuming over the new laws.

“As expected, we lost a lot of business right after we banned smoking [after the referendum],” said Weslie Evans, owner of The Great Lost Bear, a restaurant and bar on Forest Avenue.