The extent of passive smoking in the Federal Republic of Germany.

A representative survey of 1,670 persons between 14 and 65 years of age was conducted in order to obtain current data on active and passive smoking in the Federal Republic of Germany. Overall, 36.7% were smokers, 21.3% were former smokers, and 42.0% were nonsmokers. These rates vary for sociodemographic subgroups and for states, cities, and rural areas. The time pattern during the 24 hr preceding the interview is identical in shape for active as well as passive smoking. The exposed maximum time for passive smoking varies with age and sex. It lies somewhere between 2 and 15% of the observed 24 hr; the best estimates seem to be 5% for nonsmoking men and 3-4% for nonsmoking women. It consistently compares with our preliminary definition of passive smoking. A reconstruction of Hirayama's definition reveals parallel results in terms of maximum exposure time when compared with our preliminary definition. A direct comparison between both definitions showed inconsistencies to an extent that could jeopardize the results of a case-control study. Data demonstrate a massive effect of measuring techniques on study results with regard to the frequency and extent of passive smoking. They also show the vulnerability of the calculation of equivalence of actively smoked cigarettes.