We aimed to examine associations between self-reported exposure to traffic and habitual snoring/daytime sleepiness in a general population. In the RHINE III study, 12,184 adults answered questions on sleep disturbances and traffic exposure. We analyzed bedroom near road with traffic, bedroom with traffic noise, and traveling more than 60 minutes/day along busy roads as proxies for traffic exposures, using logistic regression. Adjustment factors were study center, gender, age, smoking habits, educational level, body mass index, physical activity, obstructive sleep apnea and sleep duration. Ten % lived near a busy road, 6% slept in bedroom with traffic noise, and 11% travelled along busy roads more than 60 minutes/day. Habitual snoring affected 25% and daytime sleepiness 21%. Daytime sleepiness but not habitual snoring increased with increasing pollution exposure (Medium exposure: bedroom or outdoor exposure, but not both. High exposure: both bedroom and outdoor exposure).
Bedroom with traffic noise was associated with snoring (adjusted OR 1.29, [95% CI 1.12, 1.48]). For daytime sleepiness, bedroom with traffic noise and high level of exposure to traffic pollution were significant risk factors (adjusted ORs 1.46 [1.11, 1.92] and 1.65 [1.11, 2.45]). To conclude, daytime sleepiness is associated with traffic pollution and traffic noise, while habitual snoring is only associated with traffic noise.