Indoor dampness and moulds and the risk of rhinoconjunctivitis: A systematic review and meta-analysis

Abstract

Background A substantial proportion of the world’s population is exposed to indoor dampness-related exposures. Since the 1990s studies have assessed the relation between indoor dampness and mould exposures and rhinitis, but the evidence has been inconclusive. No previous meta-analysis on this topic has been reported. Aims We conducted a systematic review and meta-analysis of studies on the relations between indoor dampness and mould and the risk of different types of rhinitis, and investigated whether these relations differ according to the type of exposure. Methods A systematic search of Ovid MEDLINE and EMBASE databases was conducted from 1950 through August 2012 and the reference lists of relevant articles were reviewed. Cross-sectional, case-control and cohort studies in children or adults were selected according to a priori criteria. Three authors independently evaluated articles using a structured form. Results Altogether 31 studies were included. The meta-analyses showed that the risk of rhinitis (Rh) was increased in relation to dampness (Effect estimate (EE) 1.82, 95% CI 1.34-2.46), visible mould (1.82, 1.56-2.12) and mould odour (2.18, 1.76-2.71) but not for water damage (1.71, 0.69-4.22). Any exposure to dampness or mould indicators was significantly related to rhinitis (2.08, 1.56-2.76). Conclusions This meta-analysis provides new evidence that dampness and moulds in the home are determinants of rhinitis. The associations were especially strong with mould odour suggesting importance of microbial causal agents. Our results provide evidence that justifies prevention and remediation of indoor dampness and mould problems and such actions are likely to reduce rhinitis.