EXPOSURE TO ENVIRONMENTAL TOBACCO-SMOKE IN NATURALISTIC SETTINGS

Background. Exposure to environmental tobacco smoke (ETS) has been ide ntified as a risk factor for chronic disease among nonsmokers. Results of epidemiological surveys suggest that the majority of nonsmokers ha ve regular ETS exposure. However, little is known about the topography of exposure. Methods. An exposure diary was used by 186 nonsmokers to self-monitor ETS exposure over a 7-day period. Subjects also complete d a questionnaire that assessed their patterns of ETS exposure. Result s. The primary source of ETS exposure was the workplace, except when t here was a smoker in the household, in which case the household was th e primary source. The presence of a smoker in the household resulted i n higher levels of exposure both at work and in other locations when c ompared with subjects without household exposure. Subjects' assessment s of exposure on the questionnaire were consistently lower than their self-monitored levels. This finding suggests that general exposure rat ings underestimate exposure. Conclusions. This study provides a new un derstanding of the patterns of ETS exposure and may help guide the dev elopment of policies and interventions designed to reduce ETS exposure .