1. of occupational exposure
Air crew monitoring
of occupational exposure
to ionising radiation
Gerhard Frasch
Ralf Stegemann
Lothar Kammerer
Bundesamt für Strahlenschutz
Germany
European ALARA-Network
9th Workshop on Occupational Exposure to Natural Radiation, Augsburg,

2. Nature of cosmic radiation
Radiation in high altitudes and dosimetry
Radiation protection for air crews
Air crew monitoring and exposure in Europe
ALARA for air crews
Air crews and health risk
Air crews and risk communication

3. Discovery of cosmic radiation
Victor Hess
Nobel Prize 1936

4. Cosmic radiation Galactic radiation Solar wind Geomagnetic field
Steady particle flux from galaxy
protons, helium nuclei, electrons
Solar wind
Continuous radiation emitted
from the corona of the sun
periodically changing during an 11-years cycle
Variation in dependence of
latitude, longitude and time
Geomagnetic field

5. Solar wind

6. Solar cycle

7. Solar cycle at Oct. 2005

8. Solar events - solar flares.
Very seldom solar events with high dose rates in high altitudes:
e.g. Feb. 1956: ~50 mSv h-1 at 20 km, ~10 mSv h-1 at 10 km

9. Magnetosphere of the earth

10. Ambient dose rate in atmosphere
Different longitudes and latitudes at 11 km, Dec. 2002

11. Particle shower in high altitudes
Proton (> 1 GeV)
pions, neutron
myons
Cruising altitudes km
electrons
neutrinos
gamma

12. Global neutron monitoring

13. Measurement of route doses
Reference instrument for ambient equivalent dose H*:
Tissue-equivalent proportional counter (TEPC)

14. Calculation of route doses
Computer programs
e.g. EPCARD, CARI, FREE, SIEVERT, PC-AIRE
Calculation codes are based on
particle fluence rates (analytical) or radiation transport (Monte Carlo)
solar potential
geomagnetic conditions
experimental validations on flight
grids of ambient dose rate measurements in atmosphere
cruising altitude and duration.

15. Uncertainty of route doses
EURADOS working group on aircraft crew exposure:
“Calculated E-values agree within ± 25%”
“Measurements and calculations of H* agree within 25%”
van Diyk, NRG, ESOREX 2005
ICRP: Person dosimetry 1
---- Hp(true) < Hp(measured) < 1.5 * Hp(true)
1.5

16. Effective doses on selected flight routes
Dose range caused by solar cycle and variation of cruising altitudes, EPCARD 3.1

17. Radiation protection for air crews
1990: ICRP-Recommendations
1996: Council Directive 96/29 EURATOM,
Art. 42: Protection of air crew
> 2000: National regulations in Member States

18. Air crew monitoring Who is monitored:
air crew personnel employed by aircraft operator (i.e. airline)
annual effective dose from cosmic radiation > 1mSv

19. Duties Calculate and accumulate individual route doses
Keep doses low by
mission scheduling (personnel)
flight planning (routes)
Instruct air crew members
nature of cosmic radiation exposure
risk of adverse health effects

20. Air crew monitoring in Europe
ESOREX 2005

21. Dose calculation programs in use
ESOREX 2005

22. Monitored air crew personnel and doses
ESOREX 2005

23. Air crews and other work sectors: mean doses

24. Air crews and other work sectors: dose distributions

25. Air crew members by gender
Germany 2003/2004

26. Air crew members by work categories
Germany 2003/2004

27. Dose distribution of air crew members
Germany 2003/2004
female
male

28. Dose distribution of air crew members
Germany 2003/2004
cabin
cockpit

29. Air crew members by age and dose
bivariate frequency distribution, Germany 2003/2004
female
male

30. Problems of ALARA airborne

31. ALARA approach for air crews
ALARA by mission planning
e.g. appropriate mix of short-range and long-haul flights
ALARA by routes and flight profile
e.g. cruse without final climb-up

32. Air crews and health risks
Work- and life-style-specific risk factors:
radiation exposure
electromagnetic fields
air-conditioned work place
smoky air (in former times)
noise
long-hour shift work
irregular rest and mealtimes
jet-lag
often and rapid climate change
exotic nutrition
UV exposure
...

33. Air crews and health risks
Epidemiological findings in air crew cohort studies:
clear healthy worker effect
enhanced or slightly enhanced risk for
air crash,
AIDS (male flight attendants),
malignant melanoma,
female breast cancer,
cataract of eye lens (elderly pilots).
no enhanced risk for
leukaemia,
other forms of cancer.
difficult to control: many work- and life-style-specific risk factors.

34. Risk communication Majority of air crew personnel: young and female
exposure before or during pregnancy
accumulation of comparatively high life-time dose

35. Risk communication Sensitive topic for public media frequent flyers
members of public

36. Risk communication New stakeholders
pilots, flight attendants, air lines
internationally organised

37. Risk communication New territory for risk communication
Lessons learned from the past
reliable dose monitoring (QM for programs and procedures)
trustful co-operation (authorities - air lines - stakeholders)
transparency instead of secrecy
comprehensible information
reasonable dose evaluation and comparisons (cosmic radiation vs. other natural and man-made sources).