Self-reported exposure to traffic pollution in relation to daytime sleepiness and habitual snoring: a questionnaire study in seven North-European cities.
Little is known about associations between traffic exposure and sleep disturbances. We examined if self-reported exposure to traffic is associated with habitual snoring and daytime sleepiness in a general population.



In the RHINE III study, 12184 adults answered questions on sleep disturbances and traffic exposure. We analysed bedrooms near roads with traffic, bedrooms with traffic noise, and travelling regularly along busy roads as proxies for traffic exposures, using logistic regression. Adjustment factors were study centre, gender, age, smoking habits, educational level, body mass index, physical activity, obstructive sleep apnoea, and sleep duration.



One in ten lived near a busy road, 6% slept in a bedroom with traffic noise, and 11% travelled regularly along busy roads. Habitual snoring affected 25% and daytime sleepiness 21%. More men reported snoring and more women reported daytime sleepiness. Having a bedroom with traffic noise was associated with snoring (adjusted OR 1.29, [95% CI 1.12, 1.48]). For daytime sleepiness, on the other hand, bedroom with traffic noise and high exposure to traffic pollution have significant risk factors (adjusted ORs 1.46 [1.11, 1.92] and 1.65 [1.11, 2.45]). Results were consistent across study centres.



Daytime sleepiness is associated with traffic pollution and traffic noise, while habitual snoring is only associated with traffic noise. Self-reported traffic exposure should be taken into account when diagnosing and planning treatment for patients with sleep disturbances, because reducing noise and pollution exposure in the bedroom may have a beneficial effect.
Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Respiratory Medicine and Sleep, Landspitali - National University Hospital of Iceland, Iceland.
Thorarinn
T
Gislason
Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway; Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
Randi J
RJ
Bertelsen
Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
Francisco Gomez
FG
Real
Department of Public Health, Aarhus University, Aarhus, Denmark.
Torben
T
Sigsgaard
Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden.
Karl A
KA
Franklin
Department of Medical Sciences, Respiratory-, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden.
Eva
E
Lindberg
Department of Medical Sciences, Respiratory-, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden.
Christer
C
Janson
Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Respiratory Medicine and Sleep, Landspitali - National University Hospital of Iceland, Iceland.
Erna Sif
ES
Arnardottir
Institute of Clinical Science, University of Gothenburg, Sweden; Department of Otorhinolaryngology, Head & Neck Surgery, Sahlgrenska Academy, Gothenburg, Sweden.
Johan
J
Hellgren
Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Respiratory Medicine and Sleep, Landspitali - National University Hospital of Iceland, Iceland.
Bryndis
B
Benediktsdottir
Department of Public Health and Clinical Medicine/Occupational & Environmental Medicine, Umeå University, Umeå, Sweden.
Bertil
B
Forsberg
Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway. Electronic address: ane.johannessen@uib.no.
Ane
A
Johannessen
D000328:Adult; D000367:Age Factors; D000393:Air Pollutants; D002947:Cities; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology*; D004781:Environmental Exposure; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009624:Noise, Transportation / Q000009:adverse effects*; D057566:Self Report; D012737:Sex Factors; D012913:Snoring / Q000453:epidemiology*; D011795:Surveys and Questionnaires
D000393:Air Pollutants
Air pollution; Daytime sleepiness; Epidemiology; Habitual snoring; Traffic noise