People smoke because of advertising. There is remarkably little evidence that advertising plays an important role in getting people to smoke, as opposed to getting them to smoke a particular brand. Given the complexity of the issue, none is likely to be forthcoming in the forseeable future. None of the widely publicized studies that have appeared in recent years, including the much-hyped research on Joe Camel, actually measured the impact of advertising on a teenager's propensity to smoke. Smoking imposes costs on society.
Secondhand smoke poses a grave threat to bystanders.
The evidence concerning the health effects of secondhand smoke is not nearly as conclusive as the evidence concerning the health effects of smoking. The research suggests that people who live with smokers for decades may face a slightly higher risk of lung cancer. According to one estimate, a nonsmoking woman who lives with a smoker faces an additional lung cancer risk of 6.5 in 10,000, which would raise her lifetime risk from about 0.34 percent to about 0.41 percent. In any case, there is no evidence that casual exposure to secondhand smoke has any impact on your life expectancy. If secondhand smoke really is dangerous, smoking ought to be banned everywhere, except in private residences.