The number of Hollywood films showing on-screen smoking is back up to the levels of the 1950s, with nearly 80 per cent of films rated for young audiences including scenes in which characters light up, according to researchers in California.

Why nearly half of all teenage smokers in the United States try cigarettes can be linked to on-screen smoking, leading the researchers to call for an adult rating for all films that depict tobacco use.

"The science is very solid. Smoking in the movies has a very substantial effect on the risk that kids will get addicted to nicotine," said Stanton Glantz, one of the researchers at the University of California San Francisco.

A sample of the top-grossing films over the last 50 years found that smoking decreased from an average of 10.7 events an hour in 1950 to 4.9 in 1982 and then shot up to 10.9 by 2002. An "event" ranges from a character lighting a cigarette to a shot of a tobacco advertisement.

A spokeswoman for the Motion Picture Association of America told the San Jose Mercury that industry statistics showed that only about half of PG-13 movies over the past two years had featured tobacco use.

"Everybody agrees that ... our industry shouldn't be encouraging or glamourizing smoking," the spokeswoman said. But the study, published in December's issue of Pediatrics, found that nearly four out of five PG-13 movies show somebody smoking cigarettes or cigars or chewing tobacco.

Source: China Daily