FAA Office of Aerospace Medicine 
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-26/18

Title and Subtitle: What Aircrews Should Know About Their Occupational Exposure to Ionizing Radiation, 2026 Edition

Report Date: 07/28/2026

Authors: Kyle Copeland, Lisa Eckhardt

Abstract:
Through advisory materials such as this report, AC 120-61 and its successors, resources offered from its Radiobiology Services website, and other related work, the FAA assists and advises those seeking to understand and minimize the hazards associated with ionizing radiation sources encountered in aviation, including recommendation of occupational exposure limits for aircrews and providing computer software for estimating the amounts of solar and galactic cosmic radiation received on flights. This report updates report DOT/FAA/AM-03/16 and is intended as an introductory briefing on the topic of occupational exposure to in-flight ionizing radiation in the form of a series of questions and answers. Air carrier crewmembers and others who regularly fly, while not classified in the U.S. as radiation workers, are considered occupationally exposed to ionizing radiation. The occupational exposures come from both natural and technological sources. The most consistent source of this exposure is naturally occurring galactic cosmic radiation, which increases as altitude increases and with increasing proximity to either geomagnetic pole. On very infrequent occasions, the Sun and other sources also contribute significantly to the ionizing radiation received during air travel. At the low doses and dose rates typically encountered in aviation, the principal health concern is not acute radiation induced injury but rather is the small increases in lifetime risks of radiation-induced diseases such as cancers and genetic defects in future generations.

Key Words: Aircrews, Ionizing Radiation, Cosmic Radiation, Cancer Risk, Hereditary Risks, Occupational Health, Radiation Exposure Limits, Pregnancy

No. of Pages: 23