Smoke-free policies are reducing heart disease related to smoke exposure, the prevalence of smoking in adults and the exposure of both adults and children to second-hand smoke. Further, such policies do not decrease the business activity of the restaurant and bar industry. A reduction in the lung cancer burden is plausible but relevant evidence will only become available in the future. The findings appear in the latest of a series of Special Reports from the International Agency for Cancer Research (IARC), published exclusively Online and in the July edition of The Lancet Oncology. The issue is dedicated to lung cancer and will be presented at the International Lung Cancer Conference, Liverpool, UK, from 9-12 July.
Dr John Pierce, University of California, San Diego, CA, USA, and Dr María León from IARC's Tobacco and Cancer Team prepared the Special Report in collaboration as part of a Working Group of scientists from around the world and the IARC secretariat. They assessed 11 proposals relating to causal 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 but evidence of causality is limited; while the third category applied to proposals where there was insufficient data to come to a conclusion. The working group comprehensively assessed peer-reviewed published work and accessible governmental reports on the effect of smoke-free policies to come to their conclusions.
The group found sufficient evidence for the following: that implementation of smoke-free policies substantially decreases second-hand smoke exposure; that smoke-free workplaces decrease cigarette consumption in continuing smokers; 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.
Strong evidence was found that smoke-free workplaces decrease the prevalence of adult smoking; that 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. But, 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 recommend that governments enact and implement smoke-free policies that conform to the WHO Framework Convention on Tobacco Control (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."
They add: "Up to now, most research has been done in high resource countries. The Working Group also recommends the establishment of a multinational surveillance system to allow assessment of the effect of these policies in low-resource and medium-resource countries."
Dr John P Pierce, University of California, San Diego, California, USA T) +1 858 822-2380) E) firstname.lastname@example.org
Dr María E León, Tobacco and Cancer Team, Lifestyle, Environment and Cancer Group, IARC, Lyon, France T) +33-4-72 73 81 71 E) LeonRouxM@iarc.fr