Tobacco companies are known to have used films and celebrities to promote their productions since at least 1927 [see reference 1].
Internal tobacco industry documents from the 1920’s and 30’s  identified endorsement contracts between the tobacco industry and film stars and studios, as well as revealing the cross-promotional value of these campaigns, and there is evidence  that paid-for tobacco product placements persisted at least as far as the 1990’s. After 1970, when tobacco advertising was banned from the US airwaves, major tobacco companies launched systematic product placement campaigns, touching hundreds of mainstream films, including multinational productions . However these studies refer only to paid-for product placement; the following evidence relates to tobacco content, irrespective of whether it is branded or generic or paid for by the tobacco industry or included for artistic or editorial purposes.
In the US, studies from the 1970’s, 80’s, and 90’s have reported that in general television broadcasting  and in programming [42, 43], tobacco use occurred on average once an hour [41-43].
A UK study of the ten top programmes most frequently watched by young people in 2004  found smoking-related scenes occurred, on average, three times every hour. The appearance of smoking differs between programme genres, with dramas showing more tobacco than comedies . Tobacco occurred on average four times an hour in Japanese drama series , five times an hour in one German crime series , and in televised sporting events, tobacco advertising occurred about one and a half times each hour . In one New Zealand study , the US animated comedy The Simpsons had the highest number of smoking characters with an average of five smoking characters each episode.
Cross-sectional studies [26, 27] have shown that adolescents whose favourite film stars smoke on-screen are more likely to have tried smoking.
A German study demonstrates that high levels of exposure to film smoking in popular internationally distributed US films is associated with an approximate twofold increase in the likelihood of being a smoker , and in the US, Sargent et al  have reported a strong, direct and exposure-related association between viewing film smoking and adolescent smoking, in which the odds of trying a cigarette was increased by a ratio of about 2.5 in those with the highest level of exposure. In Mexico exposure to film smoking was found to be associated with both current and ever smoking among adolescents . A UK study  has demonstrated a direct relation between film smoking exposure and smoking experimentation among 15 year olds, and this effect was exposure-related, with higher levels of film smoking exposure being associated with a higher risk of smoking initiation.
There have been no studies investigating an association between viewing tobacco content on television, as opposed to generic television viewing, and smoking behaviour.
However several researchers who have investigated the occurrence of tobacco on television [9, 51, 55, 56] have suggested that televised tobacco content may condition behaviour through repeated viewings, and normalise smoking among viewers, and that these influences might be stronger among young audiences, where viewers are more impressionable .
Young people who watch greater amounts of television are more likely to initiate smoking  and more likely to initiate smoking at a younger age , whilst existing young smokers are more likely to smoke more . In one study, young people exposed to five or more hours of television daily were six times more likely to initiate smoking than those who watched less than two hours , and in another, for each additional hour of daily television viewing the average age of smoking initiation decreased by 60 days . Established young smokers who watched five or more hours of television a day on average smoked between 60 and 147 cigarettes more each week than those who watched one hour or less . In a mixed youth and adult population (15 to 54 years) in India, daily television viewing and radio listening were associated with a higher likelihood of tobacco chewing (a common form of tobacco use in India) .
Although there is no evidence of the effects of tobacco content on television and smoking behaviour, given that the evidence of a causal effect of exposure to film smoking is strong, and since an estimated 27 million British homes have a television , and young people aged between 6 and 17 in Britain report that they watch television for an average of 2.5 hours each day , television is a potentially very important source of exposure to tobacco imagery among young people than films alone.