Smoke-free policies reduce smoke exposure of both adults and children reduce the prevalence of smoking in adults and reduce the risk of heart disease related to smoke exposure. Furthermore such policies do not negatively affect the restaurant and bar industry. These findings are the latest in a series of reviews and evaluations conducted by the International Agency for Research on Cancer (IARC)in Lyon France. A summary of their conclusions will be published ;in the July edition of The Lancet Oncology.

Dr John Pierce of the University of California–San Diego and Dr María León from IARC's Tobacco and cancer team in collaboration with scientists from around the world and the IARC Secretariat prepared this Special Report. The group assessed 11 proposals relating to causal effects of smoke-free policies and graded them into three categories: 'Sufficient' 'strong' and 'insufficient data to come to a conclusion'. The group comprehensively assessed all peer-reviewed published work and accessible governmental reports on the effect of smoke-free policies to reach these conclusions.

The group found sufficient evidence for the following:

• implementation of smoke-free policies substantially decreases second-hand smoke exposure
• smoke-free workplaces decrease cigarette consumption in continuing smokers
• smoke-free policies do not decrease the business activity of the restaurant and bar industry
• the introduction of smoke-free policies decreases respiratory symptoms in workers
• voluntary smoke-free home policies decrease children’s second-hand smoke-exposure
• smoke-free home policies decrease adult smoking

Strong evidence was found that smoke-free workplaces decrease the prevalence of adult smoking Smoke-free policies decrease tobacco use in youths that the introduction of smoke-free legislation decreases heart disease morbidity and that smoke-free home policies decrease smoking in youths.

However because the lead time for lung cancer to be diagnosed after exposure to a carcinogen such as cigarette smoke can be 20 or more years the group concluded that “data are not yet available regarding the expected decline in lung cancer after implementation of smoke-free policies.”

On the basis of the evidence reviewed the Working Group recommends that governments enact and implement smoke-free policies that conform to the WHO Framework Convention on Tobacco Control (WHO-FCTC). The authors conclude: “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. These benefits will be greater if these policies are enacted as part of a comprehensive tobacco-control strategy that implements all of the provisions called for by the WHO-FCTC.”

"Today tobacco smoking is the largest single avoidable cause of premature death from chronic disease in high-resource countries" said Dr Peter Boyle Director of IARC. "It has been estimated that there will be 450 million deaths caused by smoking world-wide in the first half of this century. The key priority to reduce this burden is to stop current smokers from smoking. The evidence that smoke-free policies are effective provided from this review should encourage more widespread implementation" he concluded.