Residential exposure to volatile organic compounds and asthma.
We critically analysed the literature concerning exposure to volatile organic compounds and asthma. Observational studies have consistently found a relation between volatile organic compounds and indicators of asthma, such as symptoms, peak flows, and objectively measured bronchial reactivity. In contrast, interventional studies have generally failed to find a relation between exposure to residential levels of formaldehyde and other volatile organic compounds and asthma. One hypothesis to explain the discrepancy in findings between interventional and observational studies is that the effect size is small requiring relatively large numbers of study subjects, common in observational studies but often not feasible in interventional studies. Another hypothesis is that longer duration of exposure is important, a common circumstance in observational studies where the home environment is the exposure setting. In contrast, duration of exposure in interventional studies is usually of minutes-to-hours in a chamber. Finally, the observed association in observational studies could be confounded by a factor which is a determinant of asthma and is also associated with exposure to volatile organic compounds.
Dales
Robert
R
Air Quality-Health Effects Research Section, Health Canada, University of Ottawa, 275 Slater St., 7th floor, Room 0714, Ottawa, K1A 0L2, A.L.3807-B Ontario, Canada. rdales@ottawahospital.on.ca
Raizenne
Mark
M
D016902:Air Pollution, Indoor / Q000009:adverse effects; D001249:Asthma / Q000139:chemically induced* / Q000503:physiopathology; D015340:Epidemiologic Research Design; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D009930:Organic Chemicals / Q000009:adverse effects*; D012111:Residence Characteristics; D014835:Volatilization
D009930:Organic Chemicals