PERSONAL CONSIDERATIONS ON ANNALS OF THE ICRP
Reading the draft ICRP system of radiological protection I can’t help but do the following considerations:
Thinking that these Annals are pointing to aircraft crew around the world should be at least mentioned for the Southern hemisphere the singularity of the South Atlantic Anomaly (SAA); where the Earth’s inner Van Allen radiation belt comes closest to the Earth surface dipping down to an altitude of 200 Km. This lead to an increased flux of energetic particles in this region and exposed orbiting satellite to higher-than-usual level of radiation. The SAA is of great significance for spacecraft that orbit the Earth, but also for aircrafts that flying at lower altitude (41000-45000 ft.) when crossing this region, because exposing them to several minutes of strong radiation, caused by the trapped protons in the inner Van Allen belt.
Preface line 125, I agree about “mechanisms to control exposure in aircraft are very limited” so the Annals consequently should not bring back with what was written in the Table 4, line 988 “Recommendations of the Commission…omissis…Aircraft crew – No specific additional medical surveillance. The Commission’s role, as well as identify the magnitude of individual doses, should propose a strategy for aircraft crew health protection, through medical Surveillance based on the principles that govern occupational medicine generally, as the airplanes cannot be shielded. The International Labor Organization ILO adopt since long time the protection of workers against ionizing radiation saying: All workers directly engaged in radiation work shall undergo an appropriate medical examination prior or shortly after taking up such work and subsequently undergo further medical examinations at appropriate interval. (C 115 and Radiation Protection of workers (ionizing radiation ISBN 92-2-105996-0).
(19) (20) SPE, at present, it is almost impossible to estimate in advance, it is usually made retrospectively using results from GLE neutron monitors and (25) the Commission continues to recommend the use of validated computer codes, instead of using (dosimeters and other instruments) to monitor individual exposure in aviation. I reported what was written because it seems very self-referential. Compact onboard monitors are reaching market. They can measure the whole range of radiation and provide a more accurate dose reading than mathematical models. The principle of measurement over estimation is valid in radiation protection when available, their use is encouraged especially for long haul aircrafts. With a dosimeter onboard long range aircrafts, the warnings and alarm corresponds exactly to the aircraft location avoiding the GLE’s anisotropy and the polarization of the interplanetary magnetic field. Last but not least the current cost of a dosimeter is about 5000 € and compared with the cost of a long range aircraft and saving that can give, it seems absurd not to use them on board aircrafts.
(27) Nowadays the average annual flight time in Europe for aircrew long range is 800-850 h. the 600 h is for short range aircrew.
(31) (32) (34) (35) Epidemiological studies of aircraft crew. Many other scientific studies on mortality and cancer among flight personnel were released. The previous study among German aircrew of Zeeb presented on 4-6 May at Georgetown University Washington DC cites: “The cancer risk is significantly raised (RR = 2.2, 95% CI 1.2-4.1) among cockpit crew members employed 30 years or more compared to those employed less than 10 years”. Mortality Among US Commercial Pilots and Navigators of American College of Occupational and Environmental Medicine. Other “Airline pilot cosmic radiation and circadian disruption exposure assessment from logbooks and Company records” of B. Grajewski et al. “Increased frequency of chromosome translocations in airline pilots with long term flying experience” of Young et al of Occupational and environmental medicine 2009. But the most representative examples of single study on Cancer incidence and/or mortality in aircrew for low doses of cosmic radiation carries are Meta-Analysis reports that I bring to your attention: “Cancer incidence and mortality among flight personnel: A meta-analysis” of T. Ballard et al published on Aviation Space and Environmental Medicine Vol 71, n° 3 March 2000. “Cancer incidence among male military and civil pilots and flight attendants: An analysis on published data” of G. Mastrangelo, A. Buja et al who wrote also “Cancer incidence among female flight attendants, a Meta-Analysis” Toxicol Ind Health; 21: 273-82, Department of Environmental Medicine and public Health, University of Padua. Both highlighted significant excess of melanoma (meta-SIR 2.15, 95%) and carcinoma.
Cpt Giampaolo Meotti