[ RadSafe ] Airport Whole Body Scanner Risks

[Otto G. Raabe]

Researchers: TSA Misleads Public on Scanner Safety

As the Transportation Security Administration's 
deployment of backscatter X-ray machines at 
airports draws increasing public resistance, four 
University of California researchers say the 
ionizing radiation used in these devices pose 
serious health concerns. In early April of 2010, 
the researchers­all medical and biology 
specialists­ 
<http://www.scribd.com/doc/35498347/UCSF-letter-to-Holdren-concerning-health-risks-of-full-body-scanner-TSA-screenings-4-6-2010>wrote 
the White House's science and technology 
assistant, John Holdren, expressing "urgent" 
concerns about the safety of so-called Advanced 
Imaging Technology. TSA has claimed that the 
scanners expose passengers to less than the 
equivalent of a chest X-ray, but the researchers 
say this claim is misleading because of the way backscatter X-rays work.

In a detailed paper submitted to the White House, 
the researchers identified a number of red flags 
associated with the use of this technology. 
Specifically, even though the backscatter 
machines operate at low beam powers, the majority 
of their radiation is directed at the skin and 
underlying tissue, not the entire body. The 
report says because the X-ray energy is not 
absorbed by the entire body, the skin dosage may 
be dangerously high in localized areas, exposure 
that's very different than a chest X-ray. 
Furthermore, they say no independent data exists 
on the safety of routine use of backscatter 
machines. The TSA appears to have accepted data 
from the manufacturers, without benefit of 
conducting independent risk assessment buttressed by peer-reviewed data.

The researchers' report indentified several 
categories of at-risk passengers, including 
people over 65, women who may be sensitive to 
mutagenesis provoking radiation, a breast cancer 
risk and immunocompromised individuals. The 
scientists urged the administration to assemble 
an independent panel to evaluate the scanner 
risk, but thus far, this hasn't been done, 
although TSA did engage Johns Hopkins University 
of Applied Physics Laboratory 
<http://blog.tsa.gov/2010/03/advanced-imaging-technology-radiation.html>to 
perform an engineering assessment. The university 
claimed the radiation exposure is within safe 
limits published by the American National 
Standards Institute. Similarly, it posted 
<http://www.acr.org/MainMenuCategories/media_room/FeaturedCategories/PressReleases/StatementonAirportFullbodyScanners.aspx>a 
statement from the American College of Radiology 
claiming that the backscatter machines represent 
less radiation risk than the flight itself. 
Neither of those reports addresses the 
researchers' point about concentration of 
radiation on the skin.At least two airline unions 
aren't buying TSA's assurances. The U.S. Airline 
Pilots Association and the Allied Pilots 
Association are advising their members to avoid the scanners.


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Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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