Adult-onset asthma is associated with self-reported mold or environmental tobacco smoke exposures in the home

Background: In recent years, we have gained better knowledge about the infl uence of indoor environments on respiratory symptoms and asthma. The purpos e of this study was to examine certain exposures in the home environment an d the risk of adult-onset asthma. Methods: A nested case-referent study of adult-onset asthma was performed i n a random population sample (n = 15 813), aged 20-50 years. Cases for the study included subjects reporting "physician-diagnosed" asthma (n = 174). T he referents (n = 870) were randomly selected from the whole population sam ple. The case-referent sample was investigated with a comprehensive mailed questionnaire about exposures in the home environment, asthma, respiratory symptoms, smoking habits, and atopy. Odds ratios (OR) with 95% confidence i ntervals (CI) were calculated while controlling for age, sex, smoking, and atopy. Results: Increased adjusted OR for asthma were associated with exposure to molds (OR 2.2, 95% CI 1.4-3.5), environmental tobacco smoke (OR 2.4, 95% CI 1.4-4.1), and the presence of a wood stove (OR 1.7, 95% CI 1.2-2.5). Conclusions: This population-based case-referent study indicates that self- reported domestic exposures to molds or environmental tobacco smoke can be associated with adult-onset asthma.