[Passive smoking--current position of science].

Among all indoor pollutants, environmental tobacco smoke (ETS) might be the most important. In population-based studies 30 to 60 % of the participants reported regular exposure to ETS. ETS has been classified as carcinogenic by several national and international agencies. In 2002, a paragraph on restriction of smoking at the workplace has been added to the German Workplaces Ordinance. International meta-analyses have been published on the potential health effects of ETS exposure. In these studies, the pooled relative risk (RR) for lung cancer has been estimated between 1.1 and 1.3. The pooled risk estimate for coronary heart disease (CHD) was slightly higher (1.25 - 1.35). The RR in the group with the highest exposure might be as high as 2. An increased risk has also be shown consistently for respiratory symptoms, asthma, and COPD. Because of the high incidence of CHD the public health impact of ETS exposure on CHD might be higher than the impact due to additional lung cancer cases.