Ban has key role to play in cutting illness.
And a new study by experts in California and France has said that restrictions on smoking do not affect the business activity of the restaurant and bar industry.
In an article published in The Lancet today, the researchers also said that although a reduction in lung cancer as a result of such policies is plausible, evidence to support such a health benefit will only become apparent in the future.
Dr John Pierce, from the University of California and Dr MariaLeon, from the International Agency for Cancer Research's tobacco and cancer team, assessed 11 proposals relating to effects of smoke-free policies and graded them into three categories.
Sufficient evidence means that the association was judged to be "causal"; a lesser classification of "strong" suggested that the association is consistent and the third category applied to proposals where there was insufficient data to come to a conclusion.
They found there is sufficient evidence for claims that smoke-free policies substantially decrease second-hand smoke exposure; that smoke-free workplaces decrease cigarette consumption; that smoke-free policies do not decrease the business activity of the restaurant and bar industry; that introduction of smoke-free policies decreases respiratory symptoms in workers; that voluntary smoke-free home policies decrease children's second hand smoke-exposure; and that smoke-free home policies decrease adult smoking.
There was strong evidence for claims that smoking bans decrease heart disease morbidity; and that smoke-free home policies lead to a reduction in smoking among teenagers.
The authors said: "Implementation of such policies can have a broader population effect of increasing smoke-free environments.
"Not only do these policies achieve their aim of protecting the health of non-smokers by decreasing exposure to second-hand smoke, they also have many effects on smoking behaviour, which compound the expected health benefits."