According to a new study, teen children whose parents are heavy smokers are more at risk to intergenerational transmission of the behavior.

Researchers studied the smoking patterns of parents such as duration, nicotine dependence and timing. The study shows that for each year of exposure to parental smoking, a child becomes more likely to experiment smoking or even be a heavy smoker in the future.

Researchers studied 400 parents and their adolescent children aged 12 to 17 years old. They were interviewed at the start and end of the research period and one and five years after. The study showed four adolescent patterns: 23 percent tried to smoke early, 41 percent tried to smoke later, six percent started to smoke early and regularly, and 30 percent did not smoke. Teens who had nicotine dependent parents at the start of the research had a greater risk of smoking early and regularly. Adolescent children whose parents were smokers and have a nicotine addiction were 10 times more at risk to experiment smoking or become regular smokers early on than those whose parents did not smoke.

"It is difficult to dissuade children from smoking if one or both parents are heavily dependent on cigarettes," lead researcher Darren Mays, Ph.D, MPH said. "It is also important for parents who smoke to know that their children may model the behavior, particularly if a parent is nicotine dependent." Mays is an assistant professor and public health researcher of Cancer Prevention and Control Program at Georgetown University Medical Center Lombardi.

Quitting is important not only for the parents' health but also for the children's. Social learning is an important part of intergenerational smoking if children can learn that a parent who smokes can and should quit the unhealthy habit.

The study shows that exposure to a parent's nicotine dependence is an important factor in influencing transmission of smoking in the family. It shows people a direction on how to reduce the risk. However, while the study found that parental smoking is linked with the likelihood of a child to smoke in the future, it does not prove that parental smoking is the direct cause of the child's behavior.