Thread: Scan or Grope?
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Old 01-11-2011, 12:46 PM   #32
glatt
 
Join Date: Jul 2003
Location: Arlington, VA
Posts: 27,717
Some better comments on the safety issue than I can make: http://boingboing.net/2010/11/27/mol...biologist.html

And also a letter of concern about the safety of the devices sent by a bunch of UCSF PhDs to the Obama administration.
http://www.whitehouse.gov/sites/defa...jph-letter.pdf

Basically if a handful of PhDs in the field have reviewed the public information on the scanners and are not convinced that they are safe, then what am I supposed to think?

Quote:
Unlike other scanners, these new devices operate at relatively low beam energies
(28keV). The majority of their energy is delivered to the skin and the underlying
tissue. Thus, while the dose would be safe if it were distributed throughout the volume
of the entire body, the dose to the skin may be dangerously high.


The X-ray dose from these devices has often been compared in the media to the cosmic
ray exposure inherent to airplane travel or that of a chest X-ray. However, this
comparison is very misleading: both the air travel cosmic ray exposure and chest Xrays
have much higher X-ray energies and the health consequences are appropriately
understood in terms of the whole body volume dose. In contrast, these new airport
scanners are largely depositing their energy into the skin and immediately adjacent
tissue, and since this is such a small fraction of body weight/vol, possibly by one to two
orders of magnitude, the real dose to the skin is now high.
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