Long term residential aircraft noise exposure increases the risk of acute coronary syndromes: results from environmental effect on health care and wellbeing and active interventions (ENACT) study

Background Noise from road traffic increases risk of ischemic heart disease whereas evidence of a similar effect of aircraft noise remains limited. ENACT study (EU 2025 Horizon project 101157151) is a 10 year nationwide population based study aiming to assess the effects of different environmental stressors on acute coronary syndrome (ACS), in Belgian population. Purpose To evaluate the association between residential aircraft noise exposure and the incidence of STEMI/NSTEMI between 2012 and 2021, accounting for demographic, socioeconomic, and atmospheric co-pollutants. Methods We conducted a retrospective population-based study including all Belgian citizens admitted to a hospital with STEMI or NSTEMI as primary diagnosis ICD code. Aircraft noise exposure was modelled at the living place using a 4x4 km^2 spatial grid (n=2,098 units) covering the Belgian territory. Air pollution levels were assessed using the previously described RIO geostatistical interpolation model. Concurrently, residential aircraft noise exposure from Belgium’s six major airports was mapped via Geographic Information Systems using official noise contours and spatially aligned with the RIO grid. Grid cells were categorized by noise exposure according into core (Lden > 55 dB; n=50), intermediate (1st RIO cell aside core, n=116) and broad (2nd RIO cell aside core, n=227), and zones, with non-exposed cells (n=1,705) serving as the reference. Negative binomial regression models were fitted to estimate Incidence Rate Ratios (IRR) and 95% confidence intervals (CI), adjusting for RIO cell population density, age, gender, socioeconomic deprivation (Belgian Index of Multiple Deprivation (BIMD)), urbanisation level, PM2.5 and NO2 concentrations (Air Quality). Results We identified 99,611 STEMI and NSTEMI admissions (mean age 69.1±13.8 years, 70% male). In fully adjusted models, residential aircraft noise exposure was consistently associated with a higher incidence of STEMI/NSTEMI across all zones: Broad Area (IRR 1.12, 95% CI 1.05–1.18, p < 0.001), Intermediate Area (IRR 1.15, 95% CI 1.07–1.23, p < 0.001), and Core Area (IRR 1.15, 95% CI 1.04–1.28, p = 0.007). Among environmental co-exposures, PM2.5 concentration was also correlated with increased incidence (IRR 1.02, 95% CI 1.01–1.03, p = 0.003), whereas NO2 levels showed no significant independent association (p = 0.229). Interaction analyses indicated that the association between noise exposure and ACS incidence remained stable across different levels of socioeconomic deprivation and urbanisation Conclusion This national population based study demonstrates for the first time that long term residential aircraft noise exposure is significantly associated with increased STEMI/NSTEMI incidence, independent of air quality and socioeconomic status. Furthermore, this study identifies a dose response gradient across exposure zones, and some associations below WHO standards.