Burden of disease from road traffic and railway noise in Sweden – Quantification of healthy life years lost

Abstract

Introduction: Traffic noise is commonly associated with annoyance as well as sleep disturbances and increasing evidence also suggests harmful effects on the cardiovascular system. However, national quantifications of the health burden related to traffic noise are still rare. This study aims to assess the burden of disease from road traffic and railway noise for the complete transportation net in Sweden in terms of Disability Adjusted Life-Years (DALY). Methods: The number of DALYs was assessed for annoyance, sleep disturbance and cardiovascular disease, including hypertension, myocardial infarction (MI) and stroke, using a method previously implemented by the World Health Organization (WHO). Information on population exposure to road traffic and railway noise was obtained from the Swedish Environmental Protection Agency and the Swedish Road Administration. Data on age and sex-specific disease occurrence was gathered from registers held by the Swedish Board of Health and Welfare and Statistics Sweden. Disability weights and duration were based on WHO definitions. Finally, we used research-based exposure-response functions or relative risks to estimate disease attributable to noise in each exposure category. Results: Preliminary findings show that the number of DALYs attributed to road traffic and railway noise in Sweden is approximately 36.600 and 4.000, respectively. The most important contributor to the disease burden was sleep disturbances, which accounted for a total of 22.000 DALYs, followed by annoyance, accounting for 12.100 DALYs, and cardiovascular diseases, accounting for 6.500 DALYs (stroke 2.800, MI 2.100 and hypertension 1.600 DALYs). Conclusions: Road traffic and railway noise contribute significantly to the burden of disease in Sweden each year, in particular with regard to sleep disturbance. The total number of DALYs should, however, be interpreted with caution since the underlying data has several limitations.