Cosmic radiation exposure of aircraft occupants on simulated high-latitude flights during solar proton events from 1 January 1986 through 1 January 2008

From 1 January 1986 through 1 January 2008, GOES satellites recorded 170 solar proton events. For 169 of these events, we estimated effective and equivalent dose rates and doses of galactic cosmic radiation (GCR) and solar cosmic radiation (SCR), received by aircraft occupants on simulated high-latitude flights. Dose rate and dose estimates that follow are for altitudes 30, 40, 50, and 60 kft, in that order. Mean SCR dose rates were highest 20 January 2005: to an adult, dose rates were 0.10, 0.35, 0.87, and 1.7 mSv/h; to a conceptus, doses rates were 0.11, 0.37, 0.89, and 1.6 mSv/h. GCR + mean SCR doses were highest 29 September 1989 and 20 January 2005: to an adult, highest doses in 1 h were 0.048, 0.16, 0.42, and 0.90 mSv; to an adult, highest doses in 10 h were 0.20, 0.57, 1.3, and 2.6 mSv; to a conceptus, highest doses in 1 h were 0.050, 0.17, 0.44, and 0.83 mSv; to a conceptus, highest doses in 10 h were 0.22, 0.63, 1.4, and 2.4 mSv. GCR + anisotropic-high SCR doses were highest 29 September 1989 and 20 January 2005: to an adult, highest doses in 1 h were 0.15, 0.52, 1.3, and 2.6 mSv; to an adult, highest doses in 10 h were 0.29, 0.87, 2.0, and 4.0 mSv; to a conceptus, highest doses in 1 h were 0.16, 0.55, 1.3, and 2.4 mSv; to a conceptus, highest doses in 10 h were 0.31, 0.94, 2.1, and 3.7 mSv. The dose to an adult was always less than the 20 mSv (5-y average) occupational annual limit recommended in 1990 by the International Commission on Radiological Protection. The dose to a conceptus sometimes exceeded the 0.5 mSv monthly limit recommended in 1993 by the National Council on Radiation Protection and Measurements.