The role of indoor air quality in the aetiology of asthma has again come under scrutiny in a case-control study from Perth, Western Australia. Children who had received emergency treatment for asthma were found to have been exposed to significantly higher concentrations of volatile organic compounds (VOCs) at home than community controls.

VOCs found in the home include solvents, floor adhesives, paint, cleaning products, furnishings, polishes, and room fresheners. Measurements of VOCs in the homes of 88 cases were made within two weeks of their emergency hospital visit in winter and again in summer. The homes of 104 controls were monitored during the same periods of time. The highest median concentrations were for benzene, followed by toluene and 1,2-dichlorobenzene. In the present study, the concentrations of total VOCs were low, and below currently accepted recommendations.

After controlling for potential confounding variables, children exposed to VOCs of >60μg/m³ (median level of exposure) had a fourfold increased risk of asthma. The highest odds ratios for individual VOCs were for benzene (2.9, 2.3 to 3.8), ethylbenzene (2.5, 1.2 to 5.6), and toluene (1.8, 1.4 to 2.4). For every 10 unit increase in the concentration of toluene and benzene, the risk of having asthma increased by almost two and three times respectively.

VOCs are commonly found in the home, but there is insufficient evidence about their concentrations and effects on health; levels below currently accepted recommendations were found in this study. Further research in this area is now needed.