A new national study shows for the first time how smoking bans in cities, states and counties led young people living in those areas to give up, or never take up, the use of cigarettes.

In particular, the study found that young males who were light smokers before a smoking ban was instituted in their area were more likely to give up cigarettes after a ban went into effect. Smokers who lived in areas where there was never a ban weren't likely to drop their cigarette habit.

Smoking bans did not seem to affect tobacco use among women, although their use was already below that of men.

"These findings provide some of the most robust evidence to date on the impact of smoking bans on young people's smoking," said Mike Vuolo, co-author of the study and assistant professor of sociology at The Ohio State University.

While other studies have focused on how smoking bans affect smoking rates in areas where they are instituted, this is the first national study to show how the bans affect individual smokers, Vuolo said.

Results showed that the probability of a young man smoking in the last 30 days was 19 percent for those living in an area without a ban, but only 13 percent for those who live in an area with a ban.

For women, the probability was the same (11 percent) regardless of where they lived.

The study was published in the September 2016 issue of the Journal of Health and Social Behavior.

Data on smokers came from the National Longitudinal Survey of Youth 1997. This study included 4,341 people from 487 cities who were interviewed every year from 2004 to 2011. All participants were between the age of 19 and 31 during the study. The NLSY97 is conducted by Ohio State's Center for Human Resource Research for the U.S. Bureau of Labor Statistics.

Data on city-level smoking bans came from the Americans for Nonsmokers' Rights Foundation (ANRF) tobacco policy database.

The database told the researchers which participants lived in cities where there was a comprehensive smoking ban, which means that workplaces, bars and restaurants are 100 percent tobacco free with no indoor exceptions.

The researchers found big changes in the number of bans from 2004 to 2011. The percentage of people in this study living in a city with a comprehensive ban increased from 14.9 percent to 58.7 percent during that time.

"We found that the implementation of a smoking ban reduces the odds that a young person in that location will smoke at all over time. In other words, young people are less likely to smoke once a smoking ban goes into effect," Vuolo said.

Smoking bans didn't work to reduce or end smoking for those who smoked more than a pack a day when the bans began, he said. What they did do was prevent light smokers from becoming heavy smokers.

"We found that locations that have had a smoking ban for longer periods of time have fewer youth, regardless of gender, who are heavy smokers than other areas," he said.

These results accounted for the effects of other tobacco control policies such as taxes, as well as characteristics of the individuals and where they live, said co-author Brian Kelly, professor of sociology at Purdue University and director of Purdue's Center for Research on Young People's Health.

"This study isolates the effects of smoking bans alongside multiple types of tobacco policy," Kelly said.

"Ultimately, it identifies smoking bans as the most highly effective policy tool for lawmakers who wish to reduce smoking among young people."

Vuolo said the study can't identify why smoking bans reduced smoking among men and not women. However, he noted that women in the study already smoked less than men.

"Smoking bans make men look more like women in terms of the amount that they smoke."

It is possible that men in the study were more likely to frequent bars, so they encountered smoking restrictions more often than women, Vuolo said. That may have led more men to give up smoking.

In any case, bans appear to convince social smokers to give up the habit.

"There's a lot of evidence that casual, social smokers are influenced by their environment. If they can't smoke inside with their friends at a restaurant or bar, they may choose not to smoke at all," Vuolo said.

The research was funded by the National Institute on Drug Abuse. Vuolo and Kelly collaborated with Purdue graduate student Joy Kadowaki on the research.

Article: A Multilevel Test of Constrained Choices Theory: The Case of Tobacco Clean Air Restrictions, Mike Vuolo, Joy Kadowaki, Brian C. Kelly, Journal of Health and Social Behavior, doi: 10.1177/0022146516653790, published September 2016.