Selection of a study population of flight crew exposed to cosmic radiation for an epidemiologic study.
Waters-M; Whelan-E; Yong-L; Ward-E
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :62
Aircraft flight crew are exposed to cosmic radiation of galactic and solar origin, and cosmic radiation dose (CRD) depends primarily on altitude, geomagnetic latitude and solar activity. Epidemiologic studies of flight crew currently underway at NIOSH are evaluating relationships between cumulative CRD and a variety of health outcomes. The quality of the historical CRD reconstruction for individual crewmembers is a prime determinant of the strength of these studies. The objective of this work was to develop criteria for and select a single domicile (home base) with sufficient flight crew at the high end of the range of cumulative CRD. Eleven domiciles were initially selected based on high numbers of international flight crew stationed there, then narrowed to five domiciles based on number and frequency of international destinations and more northerly latitude of the domicile. CRDs were estimated using an FAA computer model for every non-equatorial international flight into each of these domiciles. The model requires origin and destination cities, number and height of in-flight altitudes, and flight duration as input variables, and estimates dose based on the most efficient route incorporating the input constraints. Estimated flight durations were 62 obtained from published schedules and altitude assumptions were based on pilot estimates for several flight duration and route categories. CRD estimates were computed and ranged from 24.6 to 58.4 uSv/flight. The final domicile was selected balancing the highest dose range for the domicile and frequency and multiplicity of the highest dose routes. This approach allowed selection of a highly exposed study population to be used for recruitment into an epidemiologic study. Future work will include calculation of individual cumulative CRDs for study participants based at the selected domicile using detailed flight histories obtained from the company. Estimation of individual quantitative exposure estimates will strengthen the exposure-response analyses in this study.
Aircrews; Aircraft; Flight-personnel; Radiation-exposure; Radiation-levels; Radiation-properties; Radiation-sources; Epidemiology; Statistical-analysis; Exposure-levels
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana