Review of epidemiology in relation to passive smoking.

Large segments of the population in many countries are exposed to environmental tobacco smoke which means that health effects resulting from this exposure are of great public health concern. Acute irritation of the eyes and airways as well as annoyance are probably the most common effects of passive smoking. Children with smoking parents run an increased risk of bronchitis and pneumonia. This seems to be related primarily to the smoking habits of the mother. Pulmonary function changes have also been reported in passive smokers but the data are not consistent. There are a few epidemiologic studies showing an increased risk of lung cancer in nonsmokers married to smokers. These studies may be affected with various types of biases and the association can not at present be regarded as causal. Particular attention should be put on the acquisition of precise and accurate exposure information in future epidemiologic investigations on health effects related to passive smoking.