1. EVALUATION OF AIRCREW OCCUPATIONAL NOISE EXPOSURE: RESULTS OF A LARGE PERSONAL DOSIMETRY SURVEY IN A MAJOR AIRLINE
M. Klerlein, M.D – M.C. Bouton, M.D.
Occupational Medicine, Air France
ASMA 2014 annual scientific meeting, San Diego, 12 may 2014

3. WHY MEASURE NOISE EXPOSURE OF AIR CREW ? A LEGAL ISSUE…
In 2012 France put back the age of retirement from 60 to 62 years
Proven exposure to at least one of ten “hardness factors” allows leaving still at 60
One of these ten factors is “Exposure to more than a 8h continuous equivalent noise level of 85 dB(A)”
SO…
ARE AIRCREW EXPOSED TO MORE THAN 85 dB(A) ?

4. METHODS: 2 CONCEPTS
Lex,8h (continuous equivalent noise level for 8 hours work): it is the noise dose a worker is exposed to if his shift lasted 8 hours
Homogeneous Group of Exposure (H.G.E): a group of workers whose duties generate a similar noise exposure

5. PERSONAL NOISE DOSIMETRY
Dosimeters are small devices that workers can wear during the whole shift
They record the continuous equivalent noise level for small time period e.g. 1 minute, and log data during whole workshift

6. METHODS: THE ISO 9612:2009 STANDARD “Acoustics - Determination of occupational noise exposure - Engineering method “
This standard offers a statistical approach when dealing with large numbers of noise dosimetries
It includes a scientific determination of the uncertainty of measurement, due either to the device or the sampling, at the scale of each H.G.E.
A dedicated package has been used for analysis and calculation according to the ISO 9612:2009 Standard (DiagLexd, Gamba Acoustique, France)

7. EXAMPLE OF DIAGLEXD RESULTS
Size of the H.G.E.
Nb of dosimetries
Uncertainties
“True” noise dose
“Legal” noise dose
Distribution of noise dose results is tested for normality (Shapiro-Wilk test)

8. MEASUREMENTS
154 whole shift dosimetries recorded (whole shift : from briefing to hotel, and back)
1805 hours recorded
60 trips studied for the following H.G.E
Pilots Airbus 320 family (318 to 321)
Pilots Boeing 777
Pilots Boeing 747
Pilots Airbus 380
Pilots Airbus 330/340
Cabin crew Long Haul
Cabin crew Medium & Short Haul

9. TRIPS MEASURED Dosimeters worn during the whole trip (2-4 legs)
Dosimeters worn during the whole duty
(outbound & inbound) but not during layover

10. RESULTS (1) H.G.E. H.G.E. size (Nb of workers) Nb of dosimetries
Lex, 8h
(dBA)
Uncertainty
Lex,8h corrected
Cabin Crew Long Haul
9680 98
79.0
3.0
82.0
Cabin Crew Med. Short Haul
2980 19
80.7
3.1
83.8
Pilots 320
1447 8
80.3
83.1
Pilots 777
1277 11
79.8
Pilots 747
298 4
80.9
3.5
84.5
Pilots 330/340
522
77.5
80.5
Pilots 380
113 5
74.3
3.9
78.3

11. RESULTS (2) FOCUS ON SOME FLIGHT DECKS & CREW RESTS
Noise dose for the time spend at the flight deck during flight, in dB(A)
(34 recordings – mean duration 316 mn range )
Noise dose of the time spend at the crew rest during flight, in dB(A)
(106 recordings – mean duration 146 mn range )

12. CONCLUSIONS No H.G.E. exceed the 85 dBA threshold HOWEVER
For medium and short haul flights, the A320 family flight deck is clearly too noisy (mean > 82 dBA) for the cognitive demand
The noise level in crew rests is too high for a good sleep recovery for most aircrafts, except the A380.

13. Thank you for attention