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Aircraft Noise and Myocardial Infarction Mortality

Huss, Anke; Spoerri, Adrian; Egger, Matthias; Röösli, Martin For the Swiss National Cohort Study Group

Author Information
doi: 10.1097/EDE.0b013e318209d826
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The authors respond:

We thank Mark Brink1 for his interest in our work. Zurich aircraft noise levels as applied in our study were calculated on the basis of actual flight movements on an annual basis, and all calculations were carried out by the Swiss Federal Laboratories for Materials Testing and Research.2 For Zurich airport, we used the energetic average from the years 2001 to 2005, the time period covering the mortality data in our analysis. Reports on the computational noise modeling for all other airports can be accessed online.3 For these airports, we used available exposure data that usually referred to 1 year (eg, Basel year 2004, Geneva year 2000). Between 2001 and 2005, there was indeed a slight decrease of noise exposure (1-2 dB) around Zurich airport, but the exposure levels between these years are highly correlated, as the same areas are affected by aircraft noise.

We agree that it would be interesting to know whether persons with a long duration of residence entered our calculations with an underestimation of the noise levels, and to take long-term exposure history into account. However, there is uncertainty about the latency time of noise exposure and a resulting myocardial infarction (MI) event. It is well known that chronic as well as acute stress can trigger an MI.4 If myocardial infarction mortality is the consequence of acute exposure applying past exposure levels could introduce an error into the calculation. It is thus unclear how best to evaluate noise-exposure history. In addition, the high temporal correlation of the exposure levels means that firm conclusions about the relevant exposure time window cannot be drawn. The increasing risk observed with duration of residency may also reflect the fact that long-term residents were less likely to live in new or renovated buildings with better sound insulation; while 30% of the highly exposed persons lived in an old or not-renovated building at the time of the census, this percentage increased to 36% in long-term residents.

In summary, the results of our study (as well as others)5 do not suggest a well-defined threshold below which no harmful effects occur. Instead our study indicates a continuous risk increase with increasing exposure levels. Noise abatement policy should therefore focus on the health benefit that any noise reduction might bring.

Anke Huss

Institute of Social and Preventive Medicine

University of Bern

Bern, Switzerland

Institute for Risk Assessment Sciences

University of Utrecht

Utrecht, The Netherlands

Adrian Spoerri

Matthias Egger

Institute of Social and Preventive Medicine

University of Bern

Bern, Switzerland

[email protected]

Martin Röösli

Department of Epidemiology and Public Health

Swiss Tropical and Public Health Institute

Basel, Switzerland

University of Basel

Basel, Switzerland

For the Swiss National Cohort Study Group

REFERENCES

1.Brink M. Aircraft noise and MI mortality [letter]. Epidemiology. 2011;22:283-284.
2.Zurich airport. Noise mapping. Available at: www.zurich-airport.com/desktopdefault.aspx/tabid-571/. Accessed 29 November 2010.
3.Bundesamt für Zivilluftfahrt BAZL. Lärmbelastungskataster. Available at: www.bazl.admin.ch/themen/umwelt/00310/01613/index.html?lang=de. Accessed 29 November 2010.
4.Dimsdale JE. Psychological stress and cardiovascular disease. J Am Coll Cardiol. 2008;51:1237–1246.
5.Babisch W, Kamp I. Exposure-response relationship of the association between aircraft noise and the risk of hypertension. Noise Health. 2009;11:161–168.
© 2011 Lippincott Williams & Wilkins, Inc.