The cosmic radiation environment at air carrier flight altitudes and possible associated health risks

The cosmic radiation environment at air carrier flight altitudes is described and estimates are given of the amount of galactic cosmic radiation received on a wide variety of routes to and from, and within the United States. Methods are provided to assess health risks incurred by aircrews from occupational exposure to galactic radiation. On the 32 flights studied, the highest dose of galactic radiation received by a crew member who worked as many as 1000 block hours a year would be less than half the average annual limit of 20 mSv recommended by the International Commission on Radiological Protection for a non-pregnant occupationally exposed adult. A pregnant crew member who worked 70 block hours a month for 5 months would exceed the recommended 2mSv pregnancy limit on about one-third of the flights. (author)