[Passive smoking, a risk factor for lung carcinoma?].

The established elevated risk of lung cancer in smokers led to the hypothesis that environmental tobacco smoke (ETS) also causes malignancies. The solution of this question is complicated by low exposure levels and dose-response dependence, as well as threshold levels. The differences between the toxins in the main- and side-stream of tobacco smoke and also the lack of significantly elevated risk ratios in epidemiological studies do not permit scientific conclusions endorsing a connection between passive smoking and lung cancer, which has become an emotionalised issue.