Housing characteristics, reported mold exposure, and asthma in the European Community Respiratory Health Survey

Background: The effects of home dampness and mold exposure on adult asthma are not clear. Objective: We aimed to investigate the associations between housing characteristics related to dampness, mold exposure, and house dust mite levels and adult asthma in 38 study centers from the European Community Respiratory Health Survey. Methods: Data about the present home, heating and ventilation systems, double glazing, floor covers, recent water damage, and mold exposure were obtained by means of an interviewer-led questionnaire. The associations between these factors and asthma, as defined on the basis of symptoms in the last year, and of bronchial responsiveness, as determined with methacholine challenge, were evaluated. Odds ratios (ORs) were obtained by using random-effects meta-analyses adjusted within study centers for sex, age group, and smoking status. Results: Fitted carpets and rugs in the bedroom were related to fewer asthma symptoms and bronchial responsiveness (OR range, 0.69-0.91). This effect was consistent across centers and more pronounced among house dust mite-sensitized individuals. Reported mold exposure in the last year was associated with asthma symptoms and bronchial responsiveness (OR range, 1.14-1.44). This effect was homogeneous among centers and stronger in subjects sensitized to Cladosporium species. In centers with a higher prevalence of asthma, the prevalence of reported indoor mold exposure was also high. This association was observed for reported mold exposure by asthmatic subjects (Spearman r(s) = 0.46), as well as reported mold exposure by nonasthmatic subjects (r(s) = 0.54). Reported mold exposure was highest in older houses with recent water damage. Conclusion: We conclude that indoor mold growth has an adverse effect on adult asthma.