Objective: To examine if exposure to environmental
tobacco smoke (ETS) during childhood has an impact on asthma prevalence
in adults, and to identify the amount of nuisance from ETS and other
lower airway irritants (LAWIs) in a city population.
Design: A postal survey.
municipality of Örebro, Sweden.
total of 8,008 randomly selected inhabitants aged 15 to 69 years.
Measurements: Exposures, airway symptoms, and respiratory
history were assessed using a questionnaire.
The response rate was 84%. In never-smokers with childhood ETS
exposure, the prevalence of physician-diagnosed asthma was 7.6% vs
5.9% in nonexposed subjects (p = 0.036). In never-smokers without a
family history of asthma, the prevalence of physician-diagnosed asthma
in subjects reporting childhood ETS exposure was 6.8% vs 3.8% in
nonexposed subjects (p < 0.001). Subjects with childhood ETS
exposure were more likely to start smoking in adulthood. The prevalence
of ever-smokers was 54.5% vs 33.8% (p < 0.0001) in nonexposed
subjects. ETS was the most commonly reported LAWI in the total sample
(21%), followed by exercise in cold air (20%), dust (19%), exercise
(16%), perfume (15%), cold air (12%), pollen (10%), and pets (8%).
All LAWIs were more frequently reported by women.
Conclusions: Childhood exposure to ETS is associated with
an increased prevalence of asthma among adult never-smokers, especially
in nonatopic subjects. Children exposed to ETS are also more likely to
become smokers. ETS is as a major LAWI.