The relationship between traffic noise exposure and ischemic heart disease: a meta-analysis

Since publication of the World Health Organization’s report Burden of disease for environmental noise in 2011, several new studies on traffic noise and ischemic heart disease (IHD) have been published. There is thus a need for a meta-analytic update of risk estimates for these outcomes. We conducted a systematic review and retained published cohort and case-control studies using road, rail or aircraft noise as exposure. Study-specific results were transformed into risk estimates per 10dB using generalised least squares for trend estimation of summarised dose–response data. Subsequently a random effects meta-analysis was conducted. We identified 7 studies for IHD incidence and 4 for mortality. Per 10dB increase in noise, the risk estimate was 1.08 (95%CI: 1.03-1.14) for IHD incidence (total of 6,000 new cases). The risk estimate for IHD or myocardial infarction mortality accounting for a total of 22,000 deaths was 1.04 (0.98-1.09). Combined incidence and mortality risk for IHD was 1.05 (1.02-1.09). Preliminary results confirm an increase risk in IHD incidence with traffic noise exposure, and subgroup analyses suggest higher risk for MI compared to all IHD combined, for males compared to females, for road traffic noise compared to aircraft noise and for studies without air pollution adjustment compared to those with adjustment. Future analysis will address the form of the exposure-response curve before the risk estimates will be used in an assessment of the external health costs of traffic in the Swiss population.