Aircraft noise exposure assessment for a case-crossover study in Switzerland

Long-term exposure to aircraft noise has been shown to be associated with increased risk of ischemic heart diseases. However, little is known about the acute triggering effects of noise on cardiovascular diseases (CVD). We use a case-crossover design to investigate the triggering effects of night-time aircraft noise exposure on cardiovascular mortality. To that aim, we identified all death cases from the Swiss National Cohort (22000 CVD; 3000 myocardial infarctions) occurring in the vicinity of Zurich airport between 2000 and 2014. Outdoor noise exposure at participants' home addresses is calculated for the night preceding death as well as 3 to 4 control nights selected within the same month, using calculated aircraft noise impact for each registered flight. Different noise metrics such as LAeq, LAmax or NAT are used to quantify and characterize the noise impact during different night-time exposure windows. In this contribution we present the methodological approach for the noise exposure assessment and average noise levels in these different time intervals.