Movies which feature actors smoking should be given adult ratings, according to a US study.
Chicago was singled out for criticism
A report issued by the University of California suggested smoking should be treated in the same way as swearing.
Professor Stanton Glantz called on films such as Seabiscuit and Chicago to be given adult ratings because they include smoking.
He wants film-makers and studios to consider the influence that featuring smoking in films can have on children.
The report was sponsored by the charitable foundation The
Richard and Rhoda Goldman Fund and the National Cancer Institute.
A study of 775 US movies from the past five years found nearly 80% of films rated PG-13 featured smoking, while 50% of films deemed suitable for younger audiences also included tobacco use.
Among those singled out were 102 Dalmatians, Secondhand Lions and What a Girl Wants, all aimed a young audiences.
"No one is saying there should never be any smoking in
the movies," said Professor Glantz.
"What we're simply asking for is that smoking be treated by Hollywood
as seriously as it treats offensive language."
Professor Glantz would like to see more PG-13 films that feature smoking, like Chicago, given an R-rating.
Since R-rated films typically earn less money because they are not open to cinema-loving teenagers, Professor Glantz hopes this tactic might discourage "unnecessary" smoking scenes.
But the plan to rate films for smoking would not include historical figures who were known to smoke.
"For example, if they wanted to make a movie about Winston Churchill, they could show him with a cigar without triggering an R-rating, but the number of movies where that actually happens is very small," said Professor Glantz.
A spokesman for Sony said: "We are aware of the
health hazards posed by smoking and while we do not
advocate our film-makers to use smoking in our films, we cannot endorse guidelines that promote censorship or restrict creative freedom,"
The Motion Picture Association of America (MPAA), which represents the studios but is also responsible for rating movies, denied its members positively promoted cigarettes.
"We are not in the business of advertising," said Vans Stevenson, senior vice president of the MPAA.
"We are in the enterprise of creative storytelling. All elements in motion picture storytelling are determined by the creative artists involved."