Second-hand smoke's worldwide disease toll.

Despite mounting global eff orts to control tobacco use, tobacco smoking remains a common addiction with over 1 billion smokers in the world—about 40% of men and 10% of women. As a result, exposure to secondhand smoke, a known cause of morbidity and premature mortality, is widespread, occurring wherever people spend time in the presence of smokers. In The Lancet, Mattias Öberg and colleagues present fi rst estimates on the extent of worldwide exposure to second-hand smoke in 2004 and the associated burden of disease and premature death. These estimates further strengthen the evidence base supporting expansion and enforcement of comprehensive smoke-free laws. The investigators used standard comparative risk assessments, which have their origins in the approach proposed in 1953 by Levin for estimating the proportion of lung cancer cases caused by cigarette smoking. Öberg and colleagues found that about 1·0% of worldwide mortality is attributable to second-hand smoke, and that the largest burden (61%) of the morbidity is infl icted on children. Authoritative fi ndings, dating to the mid-1980s, that exposure to second-hand smoke causes morbidity and premature mortality have motivated smoke-free policies and laws worldwide. The smoke-free movement began locally but now reaches globally. WHO’s fi rst public health treaty, the Framework Convention on Tobacco Control (FCTC), legally binds all ratifying nations to implement eff ective measures to protect people from such exposure to the extent that they can do so nationally. Since adopting the FCTC, more than 60 countries have initiated campaigns for smoke-free laws and over 17 countries now have a national law requiring all workplaces and public places to be smoke free. Despite evidence that such regulations work with little to no economic burden and that they reduce smoking, much of the world’s population continues to live in communities not covered by 100% smoke-free regulations. The tobacco industry continues to attempt to slow progress towards meeting the requirements of the FCTC’s Article 8, which addresses passive smoking. multiple factors unrelated to health-system performance that could infl uence survival data.