title: Residential dampness and molds and the risk of developing asthma: a systematic review and meta-analysis.
abstract: BACKGROUND
  Studies from different geographical regions have assessed the relations between indoor dampness and mold problems and the risk of asthma, but the evidence has been inconclusive.
  
  
  OBJECTIVE
  To assess the relations between indicators of indoor dampness and mold problems and the risk of developing new asthma, and to investigate whether such relations differ according to the type of exposure.
  
  
  METHODS
  A systematic literature search of PubMed database from 1990 through March 2012 and the reference lists of recent reviews and of relevant articles identified in our search.
  
  
  METHODS
  Cohort/longitudinal and incident case-control studies assessing the relation between mold/dampness and new asthma were included.
  
  
  METHODS
  Three authors independently evaluated eligible articles and extracted relevant information using a structured form.
  
  
  RESULTS
  SIXTEEN STUDIES WERE INCLUDED: 11 cohort and 5 incident case-control studies. The summary effect estimates (EE) based on the highest and lowest estimates for the relation between any exposure and onset of asthma were for the highest estimates 1.48 (95% confidence interval [CI] 1.23-1.78, random-effects model, Q-statistic 38.75 (16), P = 0.001) ; and for the lowest estimates: 1.27 (95% CI 1.06-1.53, random-effects model, Q-statistic 38.12 (16), P = 0.000) [corrected].The summary effect estimates were significantly elevated for dampness (fixed-effects model: EE 1.33, 95% CI 1.12-1.56, Q-statistic 8.22 (9), P = 0.413), visible mold (random-effects model; EE 1.29, 95% CI 1.04-1.60, 30.30 (12), P = 0.001), and mold odor (random-effects model; EE 1.73, 95% CI 1.19-2.50, Q-statistics 14.85 (8), P = 0.038), but not for water damage (fixed-effects model; EE 1.12, 95% CI 0.98-1.27). Heterogeneity was observed in the study-specific effect estimates.
  
  
  CONCLUSIONS
  The evidence indicates that dampness and molds in the home are determinants of developing asthma. The association of the presence of visible mold and especially mold odor to the risk of asthma points towards mold-related causal agents.
authors.affiliation: Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland.
authors.forename: Reginald
authors.initials: R
authors.lastname: Quansah
authors.forename: Maritta S
authors.initials: MS
authors.lastname: Jaakkola
authors.forename: Timo T
authors.initials: TT
authors.lastname: Hugg
authors.forename: Sirpa A M
authors.initials: SA
authors.lastname: Heikkinen
authors.forename: Jouni J K
authors.initials: JJ
authors.lastname: Jaakkola
mesh_terms: D001249:Asthma / Q000453:epidemiology / Q000382:microbiology*; D015331:Cohort Studies; D004781:Environmental Exposure; D004783:Environmental Microbiology; D005658:Fungi; D006801:Humans; D015994:Incidence; D012307:Risk Factors; D012924:Social Conditions