Transportation noise exposure and cardiovascular mortality: a 15-year analysis in Switzerland

Abstract

Background: Transportation noise from road, rail and air traffic can be detrimental to health and wellbeing. Previous studies, including our own, have shown death from specific cardiovascular diseases (CVD) to be associated with these exposures. Now, with double the follow-up, integrated address history and transportation noise exposure data for multiple years corresponding to census decades, we conducted an extended analysis of the Swiss National Cohort. Methods: Mean noise exposure in 5-year periods was calculated, and three virtual sub-cohorts were defined (2000-2005, etc.) in addition to the full cohort (2000-2015). Multi-pollutant (Lden_road, Lden_rail, Lden_air), time dependent Cox proportional hazards models were applied to 3.8 mil adults (30-100 years old at 2000; age as timescale) and adjusted for sex, civil status, education, mother tongue, nationality, neighborhood socio-economic position and NO2 exposure. Results: During the 15-year follow-up, there were 249,000 CVD and 30,500 myocardial infarction deaths. In the full cohort, the relative risk for myocardial infarction mortality significantly increased by 4.1% [95% confidence interval: 2.6−5.6], 2.0% [0.9−3.1] and 3.2% [1.5−5.0] per 10 dB road traffic, railway and aircraft noise, respectively. CVD mortality was also significantly associated with road traffic noise (2.7% [2.2−3.2]) and railway noise (1.6% [1.2−2.0]) per 10 dB increase. Relative risks were remarkably consistent with our previous analyses with follow-up until 2008, and rather similar across the three virtual sub-cohorts indicating an absence of time trends for these associations. Conclusions: Cardiovascular effects of transportation noise may be modified by many factors such as building characteristics, window opening habits during the night and other lifestyle factors. For this reason, representative local data can be highly valuable for informing national noise limits aimed at protecting public health.