Road traffic noise and hypertension
- 1Unit of Environmental Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- 2Department of Occupational and Environmental Health, Stockholm County Council, Stockholm, Sweden
- Correspondence to: Dr G Bluhm Department of Occupational and Environmental Health, Stockholm County Council, Norrbacka 3rd Floor, Karolinska University Hospital, SE-171 76 Stockholm, Sweden;gosta.bluhm{at}ki.se
- Accepted 6 October 2006
- Published Online First 19 October 2006
Abstract
Background: It has been suggested that noise exposure increases the risk of hypertension. Road traffic is the dominant source of community noise exposure.
Objective: To study the association between exposure to residential road traffic noise and hypertension in an urban municipality.
Methods: The study population comprised randomly selected subjects aged 19–80 years. A postal questionnaire provided information on individual characteristics, including diagnosis of hypertension. The response rate was 77%, resulting in a study population of 667 subjects. The outdoor equivalent traffic noise level (Leq 24 h) at the residence of each individual was determined using noise-dispersion models and manual noise assessments. The individual noise exposure was classified in units of 5 dB(A), from <45 dB(A) to >65 dB(A).
Results: The odds ratio (OR) for hypertension adjusted for age, smoking, occupational status and house type was 1.38 (95% confidence interval (CI) 1.06 to 1.80) per 5 dB(A) increase in noise exposure. The association seemed stronger among women (OR 1.71; 95% CI 1.17 to 2.50) and among those who had lived at the address for >10 years (OR 1.93; 95% CI 1.29 to 2.83). Analyses of categorical exposure variables suggested an exposure–response relationship. The strongest association between exposure to traffic noise and hypertension was found among those with the least expected misclassification of true individual exposure, as indicated by not having triple-glazed windows, living in an old house and having the bedroom window facing a street (OR 2.47; 95% CI 1.38 to 4.43).
Conclusion: The results of our study suggest an association between exposure to residential road traffic noise and hypertension.
Footnotes
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Published Online First 19 October 2006
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Funding: Stockholm County Council and Sollentuna Municipality provided funding for the questionnaire survey and noise exposure assessment. These authorities had no role in the conduct of the study, interpretation of the results or the decision to send the study for publication.
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Competing interests: None declared.
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An ethics committee was consulted, but a formal approval was judged unnecessary for this study.
