Acute cardiovascular mortality in communities surrounding an international airport: triggering effects of aircraft noise, temperature, and air pollution

Environmental risk factors and cardiovascular diseases are among the leading causes of the global burden of disease. While the importance of transportation noise on health is being increasingly recognized, evidence is still lacking on the role of aircraft noise on cardiovascular health outcomes. In addition, it remains unclear whether aircraft noise can also act as a trigger of cardiovascular deaths, as observed for other environmental exposures such as air pollution.
The overall aim of this thesis was to investigate the role of night-time aircraft noise on acute cardiovascular mortality. Individual exposure to aircraft noise, air pollution, and temperature was calculated at home location with high spatial and temporal precision for 24,886 cases of cardiovascular deaths from the Swiss National Cohort occurring in the vicinity of Zurich airport between 2000 and 2015. This ‘case only’ study enabled the investigation of aircraft noise as a trigger of cause-specific cardiovascular mortality with minimum bias. The creation of an individual aircraft noise exposure assessment approach and precise nationwide air pollution models allowed the exploration of the individual and combined effects of extreme temperature and air pollution on acute fatal cardiovascular events.
This thesis provides the first evidence of the association between night-time aircraft noise exposure and acute cardiovascular mortality and highlights the importance of undisturbed, quiet nights. Since low average night-time noise levels may mask few loud events, it is essential that future noise guidelines integrate aircraft noise characteristics by using adequate exposure metrics with regards to cardiovascular health outcomes and by promoting the generalization of source-specific regulatory limits. Besides, comparing the risks of cause-specific cardiovascular mortality across several environmental exposures suggested independent triggering effects of aircraft noise, temperature, and air pollution. The association between acute cardiovascular mortality and particulate matter was confounded by nitrogen oxide, highlighting possible singularities in air pollutant mixtures in this particular setting located near a major airport. Finally, differences were observed in exposure levels and susceptibility across the different exposures and health outcomes, which are likely to take root in housing, physiological, social, and behavioural mechanisms.
Air travel will continue to be an important driver of development and economic growth. The results presented in this thesis underline the importance to address the public health impacts of aircraft noise at a policy-level and set the foundations to refine future aircraft noise regulations. In the context of a rapidly changing climate, public health and mitigation measures should be integrated in a comprehensive approach to improve environmental health as a whole and to promote sustainable, healthy, and equitable communities.