Road traffic noise and sleep disturbances in an urban population: cross-sectional study.

AIM To explore the relationship between sleep disturbances caused by traffic noise and relevant personality traits, such as extroversion-introversion, neuroticism, and subjective noise sensitivity. METHODS A cross-sectional study was carried out from January to April 2005 in a central municipality of Belgrade, the capital of Serbia and Montenegro. Noise measurements were performed at 12 measurement sites three times at daytime and twice at night. On the basis of noise measurement results, three streets with the highest and three streets with the lowest values of equivalent sound pressure level (Leq) were chosen to represent noisy (>65 dB(A)) and quiet (<55dB(A)) areas, respectively. The respondents from both areas were asked to fill out the questionnaire on noise-related health problems. The final sample consisted of 310 respondents, 192 from noisy area and 118 from quiet area. RESULTS Respondents from noisy area reported having significantly more difficulties with falling asleep, being woken up by noise at night more often, and having more difficulties with falling back to sleep. They also complained of poorer sleep quality and tiredness after sleep and they slept by an open window in summer less often. Noise annoyance, subjective noise sensitivity, and neuroticism were significantly correlated with difficulties with falling asleep, time needed to fall asleep, poorer sleep quality, tiredness after sleep, and use of sleeping pills. After adjustment for potential modifying personality traits including subjective noise sensitivity, neuroticism, and extroversion, residence in noisy area was shown to be a significant predictor for difficulties with falling asleep (odds ratio [OR], 2.71; 95% confidence interval [CI], 1.27-5.80), difficulties with falling back to sleep (OR, 1.87; 1.02-3.40), waking up at night (OR, 2.60; 1.49-4.52), sleeping by closed windows (OR, 13.51; 5.84-31.25), having poor sleep quality (OR, 2.99; 1.13-7.89), and feeling tired after sleep (OR, 2.50; 1.11-5.63). CONCLUSION Urban population living in noisy area was at higher risk for sleep disturbances than population living in the quiet area. Furthermore, sleep disturbances were significantly and positively related to personality traits of neuroticism, subjective noise sensitivity, and noise annoyance.