Characterization of Radiation Exposure at Aviation Flight Altitudes Using the Nowcast of Aerospace Ionizing Radiation System (NAIRAS)

Exposure to ionizing radiation from galactic cosmic rays (GCR) and solar energetic particles (SEP) at aircraft flight altitudes can have an adverse effect on human health. Although airline crews are classified as radiation workers by the International Commission on Radiological Protection (ICRP), in most countries, their level of exposure is unquantified and undocumented throughout the duration of their career. As such, there is a need to assess pilot ionizing radiation exposure. The Nowcast of Aerospace Ionizing RAdiation System (NAIRAS), a real-time, global, physics-based model is used to assess such exposure. The Automated Radiation Measurements for Aerospace Safety (ARMAS) measurement data set consists of high latitude, high altitude, and long-duration aircraft flights between 2013 and 2023. Here, we characterize radiation exposure at aviation flight altitudes using the NAIRAS model and compare with 45 flight trajectories from the recent ARMAS flight measurement inventory. The Nowcast of Aerospace Ionizing RAdiation System (NAIRAS) model and the Automated Radiation Measurements for Aerospace Safety (ARMAS) dosimeter were used to estimate radiation exposure for airline crews. Radiation dose rates were measured and calculated for 45 fairly representative flights between August 2022 and March 2023. Model results showed good agreement with the dosimeter and suggest that although airline crews on these flights were not exposed to radiation at levels exceeding the international standard, they would be candidates for individual radiation monitoring. The Automated Radiation Measurements for Aerospace Safety (ARMAS) dosimeter flew on board and measured dose rates for 39 corporate and 6 research flights between August 2022 and March 2023 The Nowcast of Aerospace Ionizing RAdiation System Run on Request model was run for each flight and produces dose estimates in agreement with the ARMAS dosimeter Results show that airline crew radiation exposure does not exceed the International Commission on Radiological Protection standard but could invoke individual radiation monitoring