Publikation

Zeitschrift	International Journal of Hygiene and Environmental Health
Titel der Proceedings	International Journal of Hygiene and Environmental Health

Background: Most epidemiological noise studies consider 24 hour average noise exposure levels. Our aim was to exploratively analyze the impact of noise exposure at different time windows during day and night on cardiovascular mortality. Methods: We generated Switzerland-wide exposure models for road traffic, railway and aircraft noise for different time windows for the year 2001. Combined noise source equivalent continuous sound levels (Leq) for different time windows at the most exposed façade were assigned to each of the 4.41 million Swiss National Cohort adult participants. Follow-up period was from 2000 to 2008. Hazard ratios (HR) of noise effects on various cardiovascular primary causes of death were computed by Cox regression models adjusted for socio-demographic factors and NO2 levels. Results: For most cardiovascular causes of death we obtained indications for a diurnal pattern. For ischemic heart disease the highest HR was observed for the core night hours from 01h to 05h (HR per standard deviation of Leq: 1.025, 95% CI: 1.016-1.034) and lower HR for the daytime 07h to 19h (1.018 [1.009-1.028]). Heart failure and daytime Leq yielded the highest HR (1.047 [1.027-1.068]). Conclusion: Although night-time noise was found to be most relevant for most cardiovascular causes of deaths, also the opposite pattern was observed with highest effects for daytime noise. This suggests that beside disturbed sleep other biological pathways are also important for health cardiovascular consequences of transportation noise.