According to researchers, the majority of adult smokers tried their first cigarette before they turned 18. Reuters

The number of tobacco shops in an area could affect teenagers' smoking habits, according to recent research from the University of Edinburgh in Scotland. Teens who live close to several tobacco shops are nearly 50 percent more likely to start smoking than those who do not.

The study renews an international years-old debate about whether the availability and proximity of tobacco increases the likelihood that people would start smoking, and the results could impact governments trying to develop tobacco-control laws. Often, efforts are aimed at decreasing tobacco outlets near schools, but the Edinburgh research did not find any link between school-area tobacco shops and teens' likelihood of smoking. In Scotland, where the government has set a goal of becoming a tobacco-free country by 2034, policies should target homes, not necessarily schools, the research found.

The researchers surveyed more than 20,000 students ages 13 to 15 about their smoking habits and how close they live to any of the 10,161 registered tobacco outlets in Scotland. About 10 percent of the respondents said they smoke regularly, and 28 percent said they have smoked at least once. Teens in areas with the highest densities of tobacco retailers are 47 percent more likely to smoke and 53 percent more likely to try smoking at some point.

"We were surprised by how strong an influence the retail environment was on teenagers' smoking behavior," professor Richard Mitchell said in a news release. "The results are good news because they offer a new tool with which to try and reduce smoking rates."

These findings are important, researchers argued, because the majority of adult smokers tried their first cigarette before they turned 18. People who never started smoking as teens are unlikely to become adult smokers. But "a high density of such retailers may increase the ease with which individuals can access tobacco products and the local acceptability and normalization of tobacco-related behaviors," the study read.

Many studies out of the United States reached similar conclusions. A 2005 study in Chicago found reducing the density of tobacco outlets overall would reduce youth smoking rates. In 2010, a study published in the American Journal of Public Health found that if an adult who recently quit smoking lives within 250 meters of a tobacco shop, his or her odds of continuing abstinence over six months are half those of someone who doesn't live that near to a shop.

"Our research shows that as part of this plan we need to consider regulating the number of retailers selling tobacco in our neighborhoods," lecturer Niamh Shortt said in the release.