Radiation protection aspects of the cosmic radiation exposure of aircraft crew

Abstract

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe.

Light-Ion Production and Fission Studies Using the Medley Facility at TSL

“…It has been established that, due to cosmic-ray neutrons, airflight personnel receive among the largest radiation doses in civil work [11]. Even at space flight altitudes, neutrons give a large contribution to the radiation effects on both human tissue and electronic equipment [12].…”

Natural Radiation Dose and Geomagnetic Effect

“…Because of their long mean free paths, neutrons dominate the nucleic component at lower altitudes. Near Earth, galactic cosmic rays are affected by Earth's magnetic field [1]. Charged particles are deflected by the component of a magnetic field that is perpendicular to the direction of particle motion.…”

Cosmic radiation dose in aircraft – a neutron track etch detector

“…The nuclei are 88% protons, 11% alpha particles, and about 1% heavier nuclei. The energy of nuclei ranges up to over 10 14 MeV (Bartlett, 2004).…”

“…At aircraft altitudes and temperate latitudes, representative values of the main components of ambient dose equivalent are neutrons 55%, electrons and positrons 20%, protons 15%, photons 5% and muons 5%. At sea level, the dominant component of dose equivalent is the muon component (Bartlett, 2004).…”

“…The summed components give total ambient dose equivalent. At aircraft altitude or flight level of around 15 km, one can receive a dose rate of about 10 mSv/h, where the photon and electron contribution is around 45%, neutrons 40% and protons 15% of the total dose (Bartlett, 2004;Goldhagen et al, 2002). The dose rate of the natural radiation (without a radon component) at the ground level in Croatia is nearly 0.2 mSv/h.…”