Factors associated with past household exposure to tobacco smoke.

With data that were obtained in a private census in Washington County, Maryland, in 1963, the prevalence of household exposure to tobacco smoke was determined, and factors associated with passive smoke exposure were identified among 48,342 white adults. In 1963, 52% of men and 72% of women were exposed to smoke from others at home. Smokers of both sexes were more likely to live with other smokers than were nonsmokers. However, 30% of men who never smoked and 64% of women who never smoked lived with smokers. Marriage was a primary determinant of exposure for women but not for men, with 75% of married women who did not smoke exposed but only 38% of unmarried women who did not smoke exposed. Conversely, among men who did not smoke, exposure was more common among those who were not married than among those who were married. After control for other factors associated with exposure, exposure prevalence increased with years of school among men who did not smoke but decreased with years of school among women who did not smoke. Exposure prevalence also varied slightly with housing quality and location of residence. Smoking by spouse was an accurate reflection of household exposure for women but not for men; 88% of the exposure among women who did not smoke was contributed by the spouse, whereas only 62% of exposure among men who did not smoke was from the spouse.