title: Does modern helicopter construction reduce noise exposure in helicopter rescue operations?
abstract: BACKGROUND
  During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknown.
  
  
  OBJECTIVE
  We estimated the noise exposure of the personnel for different helicopter types used during rescue operations in the Alps and in other regions of the world with special regard to the advanced types like Eurocopter EC 135 to compare the benefit of modern constructions for noise protection with earlier ones.
  
  
  METHODS
  The rescue operations over 1 year of four rescue bases in the Alps (Raron and Zermatt in Switzerland; Landeck and Innsbruck in Austria, n = 2731) were analyzed for duration of rescue operations (noise exposure). Noise levels were measured during rescue operations at defined points inside and outside the different aircraft. The setting is according to the European standard (Richtlinie 2003/10/EG Amtsblatt) and to Class 1 DIN/IEC 651. With both data sets the equivalent noise level L(eq8h) was calculated. For comparison it was assumed that all rescue operations were performed with a specific type of helicopter. Then model calculations for noise exposure by different helicopter types, such as Alouette IIIb, Alouette II 'Lama', Ecureuil AS350, Bell UH1D, Eurocopter EC135, and others were performed.
  
  
  CONCLUSIONS
  Depending on modern technologies the situation for the personnel has been improved significantly. Nevertheless noise prevention, which includes noise intermissions in spare time, is essential. Medical checks of the crews by occupational medicine (e.g. 'G20' in Germany) are still mandatory.
authors.affiliation: Institute for Occupational and Social Medicine, RWTH Aachen University, Aachen/Germany. tkuepper@ukaachen.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Küpper
authors.forename: Paul
authors.initials: P
authors.lastname: Jansing
authors.forename: Volker
authors.initials: V
authors.lastname: Schöffl
authors.forename: Simone
authors.initials: S
authors.lastname: van Der Giet
mesh_terms: D017732:Air Ambulances; D000401:Aircraft; D001317:Austria; D004430:Ear Protective Devices / Q000592:standards; D004632:Emergency Medical Services; D004738:Engineering; D006801:Humans; D009623:Noise, Occupational / Q000009:adverse effects* / Q000517:prevention & control; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis; D018635:Rescue Work; D013557:Switzerland; D013672:Technology