Neighbourhood air quality and snoring in school-aged children.

The prevalence of habitual snoring has been extensively explored in paediatric populations. Although exposure to cigarette smoke increases the risk of habitual snoring in a dose-dependent fashion, the potential contribution of air quality to habitual snoring remains unclear. 6000 questionnaires were distributed to 6- to 12-year-old children attending public schools in five distinct neighbourhoods within the city of Tehran, Iran, that were preselected based on air quality measures. Habitual snoring was defined as loud snoring ≥3 nights per week. Information regarding clinical and family-related habitual snoring risk factors was also obtained. Descriptive statistics followed by adjusted risk assessments were conducted. Among the 4322 (72%) completed datasets, the prevalence of habitual snoring was 11.6%. Partition of habitual snoring rates according to neighbourhood air quality characteristics revealed significantly higher habitual snoring frequencies among children residing in neighbourhoods with greatest pollution (24.5% and 12.1% in South and Central neighbourhoods versus 7.0% and 7.7% in North and East neighbourhoods, respectively). The regional variance in habitual snoring was primarily accounted for by an integrated measure of air quality, even after controlling for other risk factors. Environmental air quality emerges as a significant and potentially modifiable contributor to the risk for developing habitual snoring during childhood.