Radiation environment at aviation altitudes and in space

Abstract

On the Earth, protection from cosmic radiation is provided by the magnetosphere and the atmosphere, but the radiation exposure increases with increasing altitude. Aircrew and especially space crew members are therefore exposed to an increased level of ionising radiation. Dosimetry onboard aircraft and spacecraft is however complicated by the presence of neutrons and high linear energy transfer particles. Film and thermoluminescent dosimeters, routinely used for ground-based personnel, do not reliably cover the range of particle types and energies found in cosmic radiation. Further, the radiation field onboard aircraft and spacecraft is not constant; its intensity and composition change mainly with altitude, geomagnetic position and solar activity (marginally also with the aircraft/spacecraft type, number of people aboard, amount of fuel etc.). The European Union Council directive 96/29/Euroatom of 1996 specifies that aircrews that could receive dose of >1 mSv y(-1) must be evaluated. The dose evaluation is routinely performed by computer programs, e.g. CARI-6, EPCARD, SIEVERT, PCAire, JISCARD and AVIDOS. Such calculations should however be carefully verified and validated. Measurements of the radiation field in aircraft are thus of a great importance. A promising option is the long-term deployment of active detectors, e.g. silicon spectrometer Liulin, TEPC Hawk and pixel detector Timepix. Outside the Earth's protective atmosphere and magnetosphere, the environment is much harsher than at aviation altitudes. In addition to the exposure to high energetic ionising cosmic radiation, there are microgravity, lack of atmosphere, psychological and psychosocial components etc. The milieu is therefore very unfriendly for any living organism. In case of solar flares, exposures of spacecraft crews may even be lethal. In this paper, long-term measurements of the radiation environment onboard Czech aircraft performed with the Liulin since 2001, as well as measurements and simulations of dose rates on and outside the International Space Station were presented. The measured and simulated results are discussed in the context of health impact.

Malignancy in U.S. Air Force fighter pilots and other officers, 1986–2017: A retrospective cohort study

“…Military aircrew personnel may experience occupational exposure to galactic cosmic radiation [ 1 , 2 ], ultraviolet radiation [ 3 ], and non-ionizing intra-cockpit radiation [ 4 ], leading some to speculate about an increased risk of malignancy [ 5 ]. Epidemiologic investigations evaluating the relationship between aviation and cancer in both military and commercial settings have yielded conflicting results: Some studies found no difference in all-site cancer rates between aviators and non-aviators [ 6 – 10 ], one found a higher rate among aviators [ 5 ], and one found a lower rate among aviators [ 11 ].…”

Immunomodulation by ionizing radiation—impact for design of radio‐immunotherapies and for treatment of inflammatory diseases

“…Based on this equivalent dose, the effective dose was determined comprising different tissue‐dependent factors and thus representing the stochastic health risk for the whole body. As a result, it estimates the biological effectiveness of a known radiation and dose and is also indicated in Sv …”

Effect of Oxidative Stress on Cardiovascular System in Response to Gravity

“…Exposure to hazardous radiation from galactic cosmic rays and solar particle events such as solar flares significantly decreases at the altitude of LEO and below due to shielding by the Earth’s atmosphere and magnetosphere [ 38 ]. Therefore, the cause of higher cardiovascular risk in the Apollo lunar astronauts is inferred to be severe deep space radiation [ 11 ].…”