The Effect of Nightly Maximum Aircraft Noise Levels on Cardiovascular Diseases – Results of a Case-Control Study based on Secondary Data

Abstract

Background/Aim: The health effects of aircraft noise are commonly examined based on continuous sound pressure levels. However, at the same average noise level, aircraft noise tends to be more annoying than road traffic noise. This may be related to specific characteristics of aircraft noise (irregular, disruptive events, potentially leading to nightly awakenings). We aimed to examine if maximum aircraft noise levels comprise cardiovascular risks that are not adequately reflected by the risks of continuous sound levels alone. Methods: This case-control study included individuals that were insured by three large statutory health insurance funds in the Rhine-Main area of Germany. Exposure to aircraft, road and railway traffic noise in 2005 was estimated address-specifically. Cases with a new diagnosis of a cardiovascular disease (between 2006 and 2010) based on insurance claims and prescription data, i.e. myocardial infarction (n=19,632), stroke (n=25,495), and heart failure/hypertensive heart disease (n=104,145), were compared with control subjects (>500,000 for all case groups) not suffering from the respective disease. When we calculated odds ratios (OR) for categorized 24-h continuous aircraft noise levels (reference category: <40dB), we separately analyzed the risk for individuals with 24-h continuous noise levels <40dB but with nightly maximum sound levels >50dB. Results: For individuals with nightly maximum sound levels of >50dB (with 24-h continuous noise levels <40dB), we observed increased OR for myocardial infarction (OR=1.05; 95% CI 0.98-1.11), stroke (OR=1.07; 95% CI 1.02-1.13), and heart failure/hypertensive heart disease (OR=1.06; 95% CI 1.03-1.09). Conclusions: This large case-control study suggests that maximum aircraft noise levels at night negatively affect the cardiovascular system. Thus, the inclusion of this exposure group in the reference category is likely to lead to an underestimation of the risks of aircraft noise exposure. Aircraft noise protection measures should take into account not only continuous noise levels, but also maximum aircraft noise levels.