Small, B. M.
2002
A Review for The Ontario Lung Association, Small and Fleming Limited, Research Consultants in Environmental Health
| REPORT SUMMARY
1. Background
The Lung Association commissioned a public perception survey by Environics (July 2001), which reported that the majority of Ontarians expressed the view that indoor air pollution was a relatively minor problem compared to outdoor pollution. Given that concentrations of indoor pollutants can sometimes greatly exceed outdoor concentrations, The Lung Association then commissioned a report to provide an overview of current research into the respiratory health effects of common indoor air pollutants. Prepared by Mr. Bruce M. Small, P.Eng., of Small and Fleming Limited, the report was reviewed by a panel of individuals with demonstrated expertise in the field of indoor air quality and human health. Financial support for both initiative s was provided by the Laidlaw Foundation.
Each indoor contaminant was assessed individually from a respiratory health perspective. They vary widely in their nature, their potential respiratory effects, the degree of risk, the quality of evidence supporting the potential connection between exposure and health effects, and the means of remediating indoor environments to redu ce or avoid exposure.
Ample evidence of respiratory risk was found to support continued action and education concerning reduction of indoor pollutants. The respiratory health risks associated with the indoor air contaminants examined include respiratory symptoms (such as rhinitis, sore throat, hoarseness, cough, phlegm, tight chest, difficult breathing and wheezing), airway irritation, respiratory infections, asthma, airway inflammation, bronchitis, emphysema, reduced lung function, idiopathic pulmonary haemorrhage, hypersensitivity pneu monitis and lung cancer.
2. Highlights
Dampness and Mould
Dampness in housing is associated with airway inflammation, exacerbation of asthma, increased incidence of wheezing and other respiratory symptoms, and increased incidence of upper respiratory infections. Excess moisture, high humidity and water leakage often lead to the growth of mould. Mould has been associated with the same list of adverse respiratory health effects as for dampness, as well as changes in lung function, e.g. increased peak flow variability, and development of allergy to mould. Mould appears to exacerbate respiratory conditions both directly (e.g. exacerbation of existing asthma) and indirectly (e.g. increased incidence of colds and increased sensitization). Toxic mould has also been present and implicated in some cases of ideopathic pulmonary haemorrhage, but there remains some controversy over wh ether the evidence supports a causal connection.
Well-sealed building envelopes, proactive moisture and humidity control, and early remedial action at the first sign of water leakage or dampness in housing are the primary means of preventing subsequent mould growth and reducing the risk of respiratory effects. Complete removal of mouldy material is required once mould growt h has taken place.
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