Hypertension and Exposure to Noise near Airports (HYENA) - study design and noise exposure assessment

An increasing number of people live near airports, where noise and air pollution is considerable. Raised blood pressure is a major risk factor for coronary heart disease and stroke. The aim of the HYENA project is to assess the impacts on cardiovascular health (primarily reflected by high blood pressure) of noise generated by aircraft and road traffic near six major European airports. A total of 6,000 persons (45-70 years of age), who have lived at least five years in the vicinity of these airports have been selected using existing noise contours around the airports, aiming to maximise exposure contrast. . The selection of the study areas was based on existing data on aircraft noise contours, and road traffic noise levels. In order to create exposure contrast within countries, we have ensured that sufficient numbers of people had expected exposures above 60 dB(A), or below 50 dB(A). The main health outcome of interest in the HYENA study is blood pressure (BP). Automated machines are used in order to reduce observer error. These newer techniques BP measurement are now well established in clinical research and are increasing in importance in occupational and environmental medicine. Stress hormones are collected in a sub-sample of the study population (n=500) stratified according to the level of noise exposure. A standardised questionnaire has been designed to collect data on annoyance and noise disturbance from other sources than air and road traffic, and on major confounders using previously validated questions. For the individual noise exposure assessment, noise load at grid level will be calculated, since contours in the higher exposure categories are too inaccurate. To facilitate comparability of data between countries, one common noise model for aircraft noise (the Integrated Noise Model (INM)) is used to assess current exposure to aircraft noise. The noise model will have a resolution of 1 dB(A), grid size depending on the noise source (250x250 meter for aircraft and 10x10m for road traffic). Modifiers of individual exposure, such as the orientation of living and bed room towards roads, window-opening habits, sound insulation etc. are assessed by the questionnaire. For road traffic noise, models more tailored to the local situation are used. For four airports, exposure to air pollution from both aircraft and road traffic is assessed, in order to explore primarily possible confounding, but also the interactive effects of air pollution on cardiovascular disease. For each of these airports, exposures to traffic related air pollutants (NO2, PM10) will be assessed, using results from another EU funded project (APMoSPHERE ). Additional modelling will be performed at some airports where feasible. Exposure estimates will be validated where feasible by comparing modelled data with monitored data.