Authors
Waters-M; Bloom-T; Grajewski-B
Source
American Industrial Hygiene Conference and Expo, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :5-6
Abstract
A flight crew are exposed to elevated levels of cosmic ionizing radiation of galactic and solar origin and are among the more highly exP9sed occupational groups to ionizing radiation in the US, with annual doses ranging from 0.2-5 mSv. Cosmic radiation (CR) dose depends primarily on altitude and geomagnetic latitude. The purpose of this study was to measure CR doses on flights as a function of altitude, distance flown, latitude and longitude and to compare these measurements to doses estimated using an empirical model (CARl) developed by the Federal Aviation Administration. Flight segments (n=17) included north-south, east-west, trans-arctic circle and trans-equatorial flights within 3 flight duration categories. CR measurements were made with two tissue-equivalent proportional counters (TEPC), recording the full lineal energy spectrum (0.2-1000 keV/um) every minute from gate departure to gate arrival. CR dose estimates were computed using CARI-3C for the same city pairs as the survey flights. Measured doses ranged from 0.64- 15.6 uSv/flight. CARI estimates of equivalent dose were generally lower than the measurements for the same flight segments. The per- cent difference (n=17) ranged from + II % to - 46% for flights <2 hours, -1.5% to -56% for flights between 2-8 hours long, and -14% to- 44% for flights >8 hours. No trend in % difference between measured and estimated doses by flight time was found. With respect to flight latitudes, the measured and estimated doses were in fairly good agreement for trans-equatorial flights but the % difference increased for higher latitude flights. Few cosmic radiation measurement data exist for commercial aircraft routes. TEPC dose measurements tend to be greater that those estimated by the CARI model. Differences in measured versus modeled data should be considered when estimating doses CR with the CARI model for epidemiologic studies.
Keywords
Radiation; Workers; Workplace-monitoring; Exposure-levels; Occupational-exposure; Radiation-control; Radiation-exposure; Altitude
Document Type
Conference/Symposia Proceedings; Abstract
Priority Area
Work Environment And Workforce; Special Populations
Source Name
American Industrial Hygiene Conference and Expo, June 1-6, 2002, San Diego, California