Quantitative estimation of lung cancer deaths attributable to passive smoking from spousal exposure in Europe

Lung cancer is the most common cancer in the world and accounts for 12.3% of allnew cancer in Europe. About 375,000 new cases of lung cancer were estimated forEurope in 2000; 303,000 in men and 72,000 in women. The number of deaths wasabout 347,000 (280,000 in men and 67,000 in women). However, there are substantialdifferences in incidence of lung cancer in the different regions and populations withinEurope (Tyczynxki, 2003). Estimates for the year 2000 indicate that the highest agestandardizedincidence rates in men (per 100,000 inhabitants) are in Hungary (95.5),Croatia (82.5), Bosnia Herzegovina (82.2) and Yugoslavia (80.9). The lowest rates arein Sweden (21.4), Iceland (31.5), Portugal (33.9) and Norway (35.1). In women thehighest rates are observed in Denmark (27.7), Iceland (23.8), Hungary (22.6) and theUK (21.8). In women, the lowest incidence rates are observed in Spain (4.0), Belarus(5.0), and Portugal (5.5).There are also differences in temporal trends. In men, lung cancer mortality isdeclining in Northern and Western Europe (UK and Finland), although it is alreadylow and fairy stable in Sweden and Norway. In Central and Eastern Europe, however,lung-cancer mortality is increasing. In women, there was high and increasingmortality in the UK until the end of the 1980s. Since then, however, a plateau hasbeen reached and rates have started to decline. In Sweden and Norway, mortality hasbeen increasing during the past 25 years, although it is still much lower than in theUK. In Southern Europe, mortality from lung cancer is either quite low and stable incountries like Greece, or increasing at a moderate rate in Italy and Portugal.Epidemiological studies indicated cigarette smoking as the predominant cause of thedisease, but there are sound scientific data that air pollution, both indoor and outdoor,may cause lung cancer. The lung cancer risks associated with indoor and outdoor airpollutants need to be considered in the context of cigarette smoking, that is the leadingcause, and other causes of lung cancer. Workplace exposures contribute substantially,either independently or by modifying the risk of smoking. Indoor air is contaminatedby multiple pollutants generated by combustion sources, biological sources, gaseouspollutants released from household products, furnishings and building materials, andby entry of pollutants in outdoor air. These pollutants consist of a number ofcarcinogens, including several that have been linked to lung cancer, such as tobaccosmoke (ETS), radon, asbestos and other fibers. Environmental tobacco smoke (ETS) indicates the mixture of sidestream smoke andexhaled mainstream smoke that contaminates indoor air when smoking is takingplace. The inhalation of ETS by nonsmokers is generally referred to as involuntary orpassive smoking. The exposures of involuntary and active smoking differquantitatively and, to some extent, qualitatively. Nevertheless, tobacco smoking inindoor environments increases levels of respirable particles, nicotine, polycyclicaromatic hydrocarbons, carbon monoxide, acroleine, and many other substances.Measurements of components of tobacco smoke in public and commercial buildings,various workplaces, and residences have shown widespread contamination by ETS.Studies using biomarkers of exposure including nicotine and its metabolite, cotinine,have further shown that ETS components are inhaled and absorbed by nonsmokers.The adverse effects of exposure to environmental tobacco smoking (ETS) are wellestablished (Office of Environmental Health Hazard Assessment, 2005). Several wellconductedstudies have shown higher risk of coronary artery diseases, lung cancer,respiratory diseases and stroke associated with exposure to passive smoke. ETSexposure could occur in private households, work and public places. Several countrieshave enacted legislation that prohibits smoking in work and public places, but theinterest towards policies to address exposure in households is more limited. Studiesconducted in the 90 have elucidated the relationship between exposure to ETS fromspouse and lung cancer risk and relative risks (RR) have been provided, resulting in1.36 for men and 1.22 for women (Boffetta et al, 1998).The aim of the present work is to examine the overall impact of ETS exposures onlung cancer mortality in 25 European countries. The resulting figures are helpful toquantify the overall burden of indoor environment on cancer mortality.