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Re: Exposure to Phograhic Film in Airport X-ray Scanners
From: Joseph M. Greco, RSO/LSO
joseph.greco@kodak.com
Neon John beat me to it. The following is from our in-house expert on
effects of airport X-ray on photographic film. It basically summarizes the
material on the Kodak websites listed by John.
1. The FAA regulation for radiation dose for airport x-ray inspection is
less than 1 mR/inspection. For carry-on baggage scanners and many (
not all) checked baggage scanners the dose is typically much less
than 1 mR/inspection. Thus, your film will receive a very small
dose. I believe this is indeed lower than the dose you would
receive on many flights. Obviously, the dose your film will receive
in flight will depend upon the altitude, shielding from the plane,
etc. The data I have shows rates of about 17 microRoentgens/hour at
4 km and 25 microRoentgens/hour at 5 km altitude. This exposure
rate will increase as the altitude increases. However, I do not
have data at higher altitudes. If the increase was linear, I would
expect about 65 microRoentgens/hour at 10 km and, for a 6 hour
flight, a dose of 390 microRoentgens or 0.39 mR. This is within the
specification for airport scanners but, for practical purposes,
higher than the dose expected from and airport x-ray inspection
unit.
However, during the past few years new devices have been developed
for explosives detection such as the CTX devices (CTX-5000, CTX-5500
and CTX-9000) and the Examiner 3DX developed by L3 Communications
which have much higher doses for inspected materials. These devices
will fog film and are used, to the best of my knowledge, only for
checked baggage inspection.
To conclude, if the traveler carries the film on their carry-on
baggage, it probably will receive a smaller dose from x-ray security
inspection than it would during the flight but neither dose is worth
worrying about.
2. FAA regulations require airport personnel to perform a hand
inspection for film if requested by the traveler. Thus, any
traveler can request hand inspection for any speed film in the US.
Some security personnel will attempt to discourage such inspections
but, if requested, they must perform them.
Overseas, there are no such regulations. Whether a hand inspection
is done is left entirely to the discretion of local airport
personnel. My experience is that they are reluctant to perform hand
inspection and you are usually required to have your film scanned.
The best way or handling this is to have your film in your carry-on
bags; to my knowledge there are no high energy x-ray scanners used
for carry-on (their throughput is still too low).
Neon John <johngdNOSPAM@bellsouth.net> on 06/22/2000 06:40:08 PM
Please respond to radsafe@romulus.ehs.uiuc.edu
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
cc: (bcc: Joseph M. Greco/497509/EKC)
Subject: Re: Exposure to Phograhic Film in Airport X-ray Scanners
Brian Rees wrote:
>
> I have measured the exposure from one x-ray (scanner) machine and found
140
> micro rem (integrated). - Just one data (datum?) point, but I understand
> that this was reasonable based on discussions with others. Looks like
the
> security staff person was better informed than I would expect.
>
> Brian Rees
> brees@lanl.gov
No doubt that's accurate for that machine but the issue is broader
than that. As an active semi-pro photographer (amongst other
things), this is an issue that is near and dear to my heart. First
some reference information on what the film companies have to say on
this subject:
Official Kodak advice for luggage subject to Baggage Explosives
Prescan (NOT carryon at this time):
http://www.kodak.com/country/US/en/motion/support/technical/xray4.shtml
http://www.kodak.com/country/US/en/motion/newsletters/images/november99/pre
scans.shtml
Advice on handling raw and exposed film for air travel. Deals with
portal X-ray and high altitude flight exposure, among other things.
http://www.kodak.com/country/US/en/motion/support/h1/storage.shtml
This article deals with modern high speed B&W film, its handling and
problem resolution. Down near the bottom is the section on X-rays.
Summary: ONE exposure to portal X-rays is safe for film of ISO 400
speed and below. No exposure is safe for higher speed film and
infrared film.
http://www.kodak.com/cluster/global/en/professional/support/techPubs/o3/O3w
p3.shtml
This technical reference document contains most of the X-ray
information of the above one plus some elaboration. It is available
as a PDF which will make it handy to keep around.
http://www.kodak.com/cluster/global/en/professional/support/techPubs/cis98/
cis98.shtml
Kodak's FAQ on the topic. Sharp readers will note a slight variance
in advice from that in the above docs.
http://www.kodak.com/cluster/global/en/service/faqs/faq0014.shtml
The Photographics and Imaging Manufacturers Association
(http://www.pima.net/) has a standard advice package for travelers
that is available on their web site. Go to the web site, put
"airport Xray" in the search engine and click on the first hit. It
pretty much echoes Kodak's advice.
There are several issues involved. A simple risk/benefit analysis
makes the choice of what to do easy.
For submitting film to X-ray surveillance, the risks are:
* An encounter with an out-of-spec, obsolete or defective scanner
* Having to submit several inspections on a trip, both of which may
result in
* Loss of irreplaceable images.
The possible benefits include:
* Potentially faster processing through the portal, though my
experience has been that a bag with perhaps 100 rolls in it ALWAYS
gets hand-inspected even after being X-rayed.
The risks of hand inspection include:
* More hassles with the guards
* Potential for minimum wage guards to damage film, particularly
less common types such as plate film in light-tight containers.
The benefits of hand inspection include:
* No chance of X-ray damage.
* control of what happens to your film.
* Potentially faster processing, since camera equipment frequently
gets hand inspected anyway.
Since the risk of damage from X-ray exposure far outstrips the risk
from hand inspection, that is the only way I'd ever consider having
film inspected. In the US, FAA Reg 108.17 Part 108 - AIRPLANE
OPERATOR SECURITY requires that the airport security hand inspect
film of ISO 500 speed and above. As a practical matter, that means
they have to hand inspect any film when requested. Like many
photographers, I toss in a couple of rolls of ISO 1000 film just to
make sure.
Again, like many photographers, when I have to submit to airport
security, I take my 35mm film out of the plastic cans and put it in
clear plastic zip-lock bags. If I'm traveling with professional
film which must be kept cool, I put the baggies in a softside cooler
with some blue ice packs. Usually when the guard can look through
the baggie and see the film cans with the film ends sticking out, he
usually doesn't bother to open it. Other types of film such as
plate film requires some finesse since the container can't be
opened. I have traveled on time with a large format camera. I
carried an empty film pack to show the guard. I also put little
"unexposed film" tape tabs over the cassette slides. Being able to
see the empty cassette was sufficient for the guard.
Bottom line for me is that I have nothing to gain and everything to
lose by subjecting my film to a potentially malfunctioning machine
so I never allow film to be X-rayed.
John
--
John De Armond
johngdSPAMNOT@bellsouth.net
http://personal.bellsouth.net/~johngd/
Neon John's Custom Neon
Cleveland, TN
"Bendin' Glass 'n Passin' Gas"
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