Presence of damp walls at home was associated with increased prevalence of childhood asthma (adj. OR: 1.59, CI: 1.07–2.38). A series of large-population-based epidemiologic studies [53–55] have reported consistent associations between dampness and mold in the home and the risk of asthma or wheezing in children. A review of 61 studies in children and adults concluded that dampness of walls is indeed a significant risk factor for cough, wheeze, and asthma [56]. The specific causal agents related to indoor dampness are not well understood. However, studies indicate that molds may grow in these damp walls and induce immunoglobulin-E-mediated hypersensitivity reactions toxic reactions caused by mycotoxins along with nonspecific inflammatory reactions caused by irritating volatile organic compounds produced by microbes on cell wall components, such as 1,3-β-D-glucan and ergosterol [57, 58]. It has been shown that different species of fungi induce asthma by different mechanisms [59]. We have reported earlier that homes of asthmatic children have 2-fold greater amounts of fungi in the air as compared to homes of nonasthmatic children (Mandrekar S. abstract submitted to European Respiratory Society, 2008).
Children exposed to passive smoke at home had a 48% increased prevalence of asthma (adj. OR: 1.48, CI: 1.00–2.20). Numerous studies have suggested that exposure to tobacco smoke is indeed an important risk factor for the development of childhood asthma [26, 60].