Seeing characters light up on the big screen may be dangerous to your health, if you’re a child or preteen.

Seeing characters light up a smoke on the big screen not only increases the likelihood that preteens will start smoking. It also increases the odds that their smoking habit will become permanent. That’s the conclusion of a study published in the March 31, 2009, edition of the medical journal Pediatrics.

The study is the first to demonstrate a link between watching characters smoke in movies and developing a long-term smoking habit.

The researchers followed a group of students from 1999 through 2006-2007. At the start of the study, the study participants ranged in age from 10 through 14. At the end of the study, the average age of a study participant was 18.7. The researchers tracked both smoking behaviors (all participants were non-smokers at the start of the study) and the extent to which they were exposed to scenes involving smoking in movies.

After analyzing their data, the researchers concluded that exposure to smoking in movies could account for the the long-term smoking behaviors of just over one-third (34.9 per cent) of the students.

“Peer and parent smoking are typically thought to be the most powerful social influences on smoking behavior; however, our findings indicate that movie smoking exposure may be a stronger predictor of established smoking,” the researchers note. “Reducing children’s exposure to movie smoking may be a key factor in preventing long-term health consequences as a result of smoking.”