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, 18.-21.10.2005

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

Discovery of cosmic radiation Victor Hess 1883 - 1964 Nobel Prize 1936

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

Solar wind

Solar cycle

Solar cycle at Oct. 2005

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

Magnetosphere of the earth

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

Particle shower in high altitudes Proton (> 1 GeV) pions, neutron myons Cruising altitudes 11 - 15 km electrons neutrinos gamma

Global neutron monitoring

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

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.

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

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

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

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

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

Air crew monitoring in Europe ESOREX 2005

Dose calculation programs in use ESOREX 2005

Monitored air crew personnel and doses ESOREX 2005

Air crews and other work sectors: mean doses

Air crews and other work sectors: dose distributions

Air crew members by gender Germany 2003/2004

Air crew members by work categories Germany 2003/2004

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

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

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

Problems of ALARA airborne

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

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 ...

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.

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

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

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

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).