Background: The home is the predominant environment for exposure to many environmental irritants such as air pollutants and allergens. Exposure to common indoor irritants including volatile organic compounds, formaldehyde and nitrogen dioxide, may increase the risk of snoring for children. The aim of this study was to investigate domestic environmental factors associated with snoring in children.

Methods: A school-based respiratory survey was administered during March and April of 2002. Nine hundred and ninety six children from four primary schools within the Perth metropolitan area were recruited for the study. A sub-group of 88 children aged 4-6 years were further selected from this sample for domestic air pollutant assessment.

Results: The prevalences of infrequent snoring and habitual snoring in primary school children were 24.9% and 15.2% respectively. Passive smoking was found to be a significant risk factor for habitual snoring (odds ratio (OR) = 1.77; 95% confidence interval (CI): 1.20-2.61), while having pets at home appeared to be protective against habitual snoring (OR = 0.58; 95% CI: 0.37-0.92). Domestic pollutant assessments showed that the prevalence of snoring was significantly associated with exposure to nitrogen dioxide during winter. Relative to the low exposure category (<30 microg/m3), the adjusted ORs of snoring by children with medium (30 - 60 microg/m3) and high exposures (> 60 microg/m3) to NO2 were 2.5 (95% CI: 0.7-8.7) and 4.5 (95% CI: 1.4-14.3) respectively. The corresponding linear dose-response trend was also significant (P = 0.011).

Conclusion: Snoring is common in primary school children. Domestic environments may play a significant role in the increased prevalence of snoring. Exposure to nitrogen dioxide in domestic environment is associated with snoring in children.