Ten years ago, the Georgia Legislature passed a law prohibiting smoking in bars and restaurants. It was promoted as a way to improve “the health, comfort and environment’’ of Georgians.

The law, still in effect, has some exemptions, including allowing smoking in an establishment if it prohibits entry to anyone under age 18.

Despite the 2005 law, a recent study from Georgia State University found some surprising results on smoking.

Researchers found that the percentage of Georgia restaurants and bars allowing smoking nearly doubled in the first six years after the law’s passage.

Georgia State researchers also found a significant number of owners taking advantage of exemptions in the law.

The percentage of restaurants and bars in Georgia that allowed smoking rose from 9.1 percent in 2006 to 17.6 percent in 2012, according to the study, published last month in the journal Preventing Chronic Disease: Public Health Research, Practice and Policy.

The study did not address growth in smoking in Georgia bars and restaurants since 2012.

“I have no reason to think that things have changed,” Michael Eriksen, an author of the study,  told GHN.

“While the law is well known and well accepted, restaurants have figured out how to work within the law and allow smoking,” said Eriksen, dean of the School of Public Health at Georgia State.

Researchers found “a significant increase in the percentage of establishments that allow smoking when minors are present,” most likely in designated smoking areas and outdoor patios. Bars and restaurants can allow smoking if designated smoking areas are outdoors or in rooms with separate ventilation systems.

Manuel’s Tavern, a famous Atlanta establishment frequented by politicians and journalists, allowed indoor smoking to continue after the law’s passage, using the adults-only exemption.

But at the beginning of 2014, Manuel’s went in the opposite direction, removing ashtrays and prohibiting indoor smoking.

Brian Maloof, the owner, said Wednesday that the reaction “has been very positive.”

“People say, ‘I can finally come in here because there’s no smoking.’ ”

But Maloof added, “Had I done it five years earlier, I think it would have been bad for business.’’

June Deen of the American Lung Association said Wednesday that the Georgia State study “is truly alarming.”

She said a probable lack of enforcement of the 2005 law would factor into the growth of indoor smoking.

“I think there has been a lot less discussion on secondhand smoke,’’ Deen said. “The people who are the most harmed are the workers in these establishments. They are people who may not have a lot of employment options.”

Secondhand smoke is especially damaging “to the very young and the very old,” she noted.

The CDC says there is no risk-free level of exposure to secondhand smoke, which contains more than 7,000 chemicals.

Since the landmark 1964 Surgeon General’s Report on tobacco, 2.5 million adults who were nonsmokers died because they breathed secondhand smoke, the CDC says.

Exposure causes numerous health problems in infants and children, including more frequent and severe asthma attacks, respiratory infections, ear infections, and sudden infant death syndrome. Adults can face coronary heart disease, stroke, and lung cancer.

The GSU researchers urged policymakers to strengthen the Georgia law by making restaurants and bars 100 percent smoke-free, without exemptions.

They said Georgia is one of  only 15 states that do not have a 100 percent smoke-free restaurant or bar law.