Re: Airport X-ray Security Scanner

[Glenn Roberts <glenn@u1st.com>]

BLHamrick@aol.com wrote:

"The critical phrase here is "based on the manufacturer's claims..."
These devices have been used in prison environments, but my
understanding is there are questions remaining regarding the default
settings of the device, how they can be changed, and who can change
them.  The total dose should be about 3 microR, but I believe that can
be over-ridden, and if someone can do it, they will do it...Now, would
the maximum output pose a danger?  I don't know, I haven't looked at
this in sufficient detail."

The only reason that I qualified my initial posting is because I was
working from memory and have not conducted any measurements or
calculations myself.  While I am one of the few members of industry that
participate in the CRCPD forum (and appreciate that privilege), I have
no vested interest in the scanners or any company associated with them. 
However, I recall the presentation to be professional with substantial
documentation.  I also recall vehement opposition to there use.  After
reviewing the links posted to RadSafe, several independent studies by
reputable labs confirmed the dose.  The device has redundant safety
systems that can't be overridden by the operator.  Safety devices must
be easy to use and difficult to override.  From my review, I believe
both requirements are met with these devices.

Having looked at the image on Rapiscan's website, I agree that it may
not be flattering to some individuals.  However, the alternatives
(physical pat down search) are much more personally objectionable.  In
addition, pat down searches may not find razor blades, bobby pins, or
small contraband packages, and also expose the search to physical and
biological hazards associated with close contact (as pointed about by a
retired/former police officer turned rad regulator at the CRCPD
meeting).  In my opinion, there are obvious societal benefits from the
use of these devices, in prisons, airports, and is some additional
situations.  By a realist and understanding that a radiation risk is not
inherently different from other risks, I would go out on a limb and risk
severe criticism by saying that I would not object to my own children
being scanned (<1 millirem/yr for 333 scans at the stated dose per scan)
going to school.  I realize that I speak for no one else and the public
would never except this position.

Finally, as another person pointed out, the dose is so low because it
uses backscatter and the beam energy is only 50 kVp.

Glenn Roberts
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html