title: Organ Doses to Airline Passengers Screened by X-Ray Backscatter Imaging Systems.
abstract: Advanced imaging technologies (AIT) are being developed for passenger airline transportation. They are designed to provide enhanced security benefits by identifying objects on passengers that would not be detected by methodologies now used for routine surveillance. X-ray backscatter imaging is one AIT system being considered. Since this technology is based on scanning passengers with ionizing radiation, concern has been raised relating to the health risks associated with these exposures. Recommendations for standards of radiation safety have been proposed by the American National Standards Institute published in ANSI/HPS N43.17-2009. A Monte Carlo based methodology for estimating organ doses received from an X-ray backscatter AIT system is presented. Radiological properties of a reference scanner including beam intensity, geometry and energy spectra were modeled based on previous studies and physical measurements. These parameters were incorporated into a Monte Carlo source subroutine and validated with comparison of simulated versus measured data. One extension of this study was to calculate organ and effective dose on a wide range of potential passengers. Computational phantoms with realistic morphologies were used including adults of 5th, 25th, 50th, 75th and 95th percentile weight, children of 5th, 50th and 95th percentile weight, and the developing fetus of 15, 25, and 38 weeks after conception. Additional sensitivity studies were performed to evaluate effects of passenger positioning within the scanner, energy spectrum and beam geometry, as well as failure mode analyses. Results for routine operations yielded a maximum effective dose to the adult and pediatric passengers of 15 and 25 nSv per screen, respectively. The developing fetus received a maximum organ dose and whole body dose of 16 nGy and 8.5 nGy per screen, respectively. The sensitivity analyses indicated that variations in positioning, energy spectra, and beam geometry yielded a range of effective doses per screen that were an order of magnitude below the ANSI recommendation.
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: Elliott J
authors.initials: EJ
authors.lastname: Stepusin
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Maynard
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: Shannon E
authors.initials: SE
authors.lastname: O'Reilly
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: Sadije
authors.initials: S
authors.lastname: Redzovic
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: Wesley E
authors.initials: WE
authors.lastname: Bolch
authors.affiliation: a   J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 and.
authors.forename: David E
authors.initials: DE
authors.lastname: Hintenlang
authors.affiliation: b   Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523-1601.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Borak
mesh_terms: D000328:Adult; D064870:Air Travel; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011859:Radiography / Q000009:adverse effects* / Q000295:instrumentation; D011874:Radiometry; D012542:Scattering, Radiation; D014965:X-Rays / Q000009:adverse effects