Teenagers who regularly watch films showing smoking are more likely to smoke than those who are rarely exposed to such movies, a study has found.
Researchers at the University of Bristol looked at data on 5,166 15-year-olds, all of whom were taking part in the Children of the 90s project.
The youngsters were given a list of 50 films which were released between 2001 and 2005 and asked which ones they had seen.
The results, which are published in Thorax journal, revealed that teenagers who had seen the most films showing smoking were 73 per cent more likely to have tried smoking than those who had seen the least.
In addition, they were almost 50 per cent more likely to be current smokers than those who had seen the fewest films showing smoking.
Lead researcher Dr Andrea Waylen, from the School of Oral and Dental Sciences, said: 'More than half the films shown in the UK that contain smoking are rated UK15 or below, so children and young teenagers are clearly exposed.
'Our results confirm an association between this exposure and youth smoking in this country, indicating that raising the certification to 18 in the UK is likely to lower smoking rates among youth.'
Deborah Arnott, chief executive of campaign group Ash, said that the UK ban on tobacco advertising has led to a fall in smoking rates in children.
But she agreed that smoking in films 'encourages young people to become smokers themselves'.
Ms Arnott urged the government to work with the film industry to tackle the problem.