Chiang Mai Journal of Science

      Aircrew members are occupationally exposed to higher levels of galactic cosmic radiation than the general population in most parts of the world. The International Commission on Radiological Protection (ICRP) is concerned by the exposure of aircrews to cosmic radiation. The cosmic radiation intensity in the Earth atmosphere depends on many factors, e.g., the solar activity, altitude, and geomagnetic vertical cutoff rigidity on Earth. This study aimed to calculate the occupational radiation dose for aircraft crews during the solar minimum and maximum on fl ights from Suvarnabhumi Airport (BKK), Thailand, to 11 destinations worldwide. Based on the Monte Carlo simulation code of CARI-7 and JISCARD GUI, the cosmic radiation doses on fl ights was calculated. The maximum dose of a roundtrip fl ight (Bangkok–Helsinki) during the solar minimum condition was approximately 97.4 μSv (CARI-7) and 84.7 μSv (JISCARD GUI). The maximum radiation dose corresponded to 110 and 20 roundtrips for general aircraft crew and pregnant crew, respectively. This fi nding indicates that the polar-latitude region of Helsinki fl ights at low vertical cutoff rigidity ranges is of concern in terms of high-exposure cosmic radiation. The uncertainty associated with the result of the two codes was less than 30%. Therefore, the results were in reasonable agreement, and the codes could be used to calculate the exposure of aircraft crew to cosmic radiation.