WHO Guidelines for Indoor Air Quality: Dampness and Mould
About this book
The WHO Guidelines for Indoor Air Quality: Dampness and Mould, published in 2009, synthesize the global evidence on the health effects of indoor damp and mold conditions and provide guidance for building professionals, public health practitioners, and policy makers on prevention and remediation. The document represents the most comprehensive assessment of the relationship between the built environment's moisture performance and human health outcomes. The guidelines begin with an analysis of the scale of the problem: based on available surveys, damp conditions affect between 10 and 50 percent of the indoor environments in which people in developed countries live and work, and the proportion is much higher in developing countries and in certain specific building types including social housing and school buildings.
The health burden associated with this prevalence is substantial. The scientific review covers three categories of health effects associated with dampness and mould: respiratory effects (asthma, rhinitis, respiratory infections, and bronchitis), effects on the immune system (allergic sensitization and hypersensitivity pneumonitis), and neurological and other effects. The review concludes with a high degree of scientific confidence that exposure to indoor damp and mould is causally associated with upper and lower respiratory tract health effects in previously healthy people, and that this relationship is even stronger in children and people with pre-existing respiratory conditions.
For building design, the guidelines emphasize the importance of preventing moisture accumulation through appropriate envelope design (preventing both condensation and rain infiltration), ventilation design (controlling indoor humidity and removing moisture produced by occupants and activities), and appropriate material selection (avoiding the use of materials that support mould growth in locations likely to experience moisture). They also address the procedural requirements for mould remediation when it does occur. Sources: World Health Organization (who.int); WHO Guidelines for Indoor Air Quality: Dampness and Mould 2009 official publication; Lancet, Indoor Air, and similar journals cited in the document.