A nation-wide study in Germany has revealed that 20 per cent of adolescents smoke.
The German Health Interview and Examination Survey of tobacco consumption by children and adolescents covered almost 7,000 girls and boys, aged 11 to 17.
For the study, experts at the Robert Koch Institute gathered data on the current smoking status and on exposure to passive smoking for the years 2003 to 2006.
The researchers then examined possible factors influencing the findings that included the social status of the family, the type of school attended by the adolescents, and the smoking status of parents and friends.
Thomas Lampert, who has presented the study in the current edition of Deutsches Arzteblatt International, says that it shows that friends and the type of school have greater influence on smoking behaviour than the parents do.
He says that the probability that an adolescent starts smoking is markedly greater when his or her friends smoke, but this risk is hardly increased if the parents smoke.
The study has also found that students at general secondary schools, intermediate schools or comprehensive schools smoke much more frequently than do pupils at high school.
It also suggests that the number of smoking girls is almost as high as that of smoking boys, though girls smoke fewer cigarettes.
The report says that the average age of starting smoking is between 13 and 14 years for both genders.
It further states that social status hardly affects adolescents' smoking behaviour.
In contrast, say the researchers, smoking parents expose their children to additional stress from passive smoking.