Estimated individual annual cosmic radiation doses for flight crews.

INTRODUCTION: Individual annual cosmic radiation doses for fulltime airline crewmembers were calculated for 12 consecutive months using data from flight profiles and previously reported cosmic radiation intensity measurements at various altitudes.
METHODS: Every flight of each crewmember was analyzed using block time and aircraft flight profiles. Actual flight time at various flight levels was first calculated, then cumulative total body radiation doses were calculated for each flight phase and altitude.
RESULTS: Cabin crewmembers averaged 673 block hours (range 906-273 h) and pilots 568 block hours (range 833-168 h). Average annual cosmic ray dose for cabin crews was 2.27 mSv x a(-1) (range between 3.1 - 0.72 mSv x a(-1)). Long-distance MD11 flight captains received the highest annual doses of 2.19 mSv x a(-1) (2.83 - 1.08 mSv x a(-1)). M.D.80 pilots who also fly long high-altitude sectors in Europe received 1.94 mSv x a(-1) (2.37 - 1.12) and other aircraft type cockpit crews averaged between 1.49 - 1.26 mSv x a(-1).
CONCLUSION: The calculated individual doses reflect the type of aircraft flown and the amount of flight time. The calculated doses are lower than those received by simply assuming constant radiation exposure at all altitudes during flight. Annual individual doses are well below the maximum 5 mSv x a(-1) allowed by the national laws.