title: Measurement of environmental tobacco smoke exposure among adults with asthma.
abstract: Because the morbidity and mortality from adult asthma have been increasing, the identification of modifiable environmental exposures that exacerbate asthma has become a priority. Limited evidence suggests that exposure to environmental tobacco smoke (ETS) may adversely affect adults with asthma. To study the effects of ETS better, we developed a survey instrument to measure ETS exposure in a cohort of adults with asthma living in northern California, where public indoor smoking is limited. To validate this survey instrument, we used a passive badge monitor that measures actual exposure to ambient nicotine, a direct and specific measure of ETS. In this validation study, we recruited 50 subjects from an ongoing longitudinal asthma cohort study who had a positive screening question for ETS exposure or potential exposure. Each subject wore a passive nicotine badge monitor for 7 days. After the personal monitoring period, we readministered the ETS exposure survey instrument. Based on the survey, self-reported total ETS exposure duration ranged from 0 to 70 hr during the previous 7 days. Based on the upper-range boundary, bars or nightclubs (55 hr) and the home (50 hr) were the sites associated with greatest maximal self-reported exposure. As measured by the personal nicotine badge monitors, the overall median 7-day nicotine concentration was 0.03 microg/m(3) (25th-75th interquartile range 0-3.69 microg/m(3)). Measured nicotine concentrations were highest among persons who reported home exposure (median 0.61 microg/m(3)), followed by work exposure (0.03 microg/m(3)), other (outdoor) exposure (0.025 microg/m(3)), and no exposure (0 microg/m(3); p = 0.03). The Spearman rank correlation coefficient between self-reported ETS exposure duration and directly measured personal nicotine concentration during the same 7-day period was 0.47, supporting the survey's validity (p = 0.0006). Compared to persons with no measured exposure, lower-level [odds ratio (OR) 1.9; 95% confidence interval (CI), 0.4-8.8] and higher-level ETS exposures (OR 6.8; 95% CI, 1.4-32.3) were associated with increased risk of respiratory symptoms. A brief, validated survey instrument can be used to assess ETS exposure among adults with asthma, even with low levels of exposure. This instrument could be a valuable tool for studying the effect of ETS exposure on adult asthma health outcomes.
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Medicine, University of California, San Francisco, California 94117, USA. eisner@itsa.ucsf.edu
authors.forename: M D
authors.initials: MD
authors.lastname: Eisner
authors.forename: P P
authors.initials: PP
authors.lastname: Katz
authors.forename: E H
authors.initials: EH
authors.lastname: Yelin
authors.forename: S K
authors.initials: SK
authors.lastname: Hammond
authors.forename: P D
authors.initials: PD
authors.lastname: Blanc
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor / Q000032:analysis; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology*; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods / Q000592:standards*; D062665:Epidemiological Monitoring; D006801:Humans; D009538:Nicotine / Q000032:analysis; D016273:Occupational Exposure / Q000032:analysis; D015203:Reproducibility of Results; D018570:Risk Assessment; D011795:Surveys and Questionnaires / Q000592:standards*; D014028:Tobacco Smoke Pollution / Q000032:analysis*
chemical_list: D014028:Tobacco Smoke Pollution; D009538:Nicotine