Re: airport and radiation safety

["David W. Lee" <lee_david_w@lanl.gov>]

Mauro:

	The degree of concern that one might choose to manifest would also depend
upon the existing laws of your country regarding x-ray baggage checking
machines.  I certainly am not familiar with such laws/directives of Italy,
but in the United States, the situation basically is this.  Federal law,
specifically Title 21, Code of Federal Regulations (CFR), Part 1020.40 sets
forth the radiation safety requirements that manufacturers of cabinet x-ray
systems must meet in order to be able to sell such equipment to members of
the general public.  In the US, the term 'cabinet' x-ray machine includes
airport baggage x-ray equipment.  The radiation safety standard, in
addition to interlocks, is that the radiation emitted from the 'cabinet'
shall not exceed an exposure of 0.5 milliroentgen in one hour at any point
five centimeters outside the external surface.  This low, permissible
amount of emitted radiation was chosen under the rationale that if the unit
were to emit 0.5 mR in any one hour at 5 cm away, a member of the public,
under any 'reasonable/rational' set of exposure scenario parameter values
(exposure distance, hours each day at that position, etc.) would not
sustain a dose in excess of 500 mrem in any calendar year.

	After this 1968 federal law had been on the books for some years, the
ICRP/NCRP set the public annual dose limit down to 100 mrem.  But even
still, any realistic set of exposure scenario parameter values still
results in an estimated annual dose to a member of the public less than 100
mrem, even assuming that the unit 'leaks' or emits radiation at its maximum
permissible rate.  Finally, in the United States, the individual States
vary as to the extent to which they choose to regulate such x-ray
equipment.  So most States don't worry about such units.  The bottom line
is that as a result of the federal radiation emission standard for such
equipment, the equipment can be freely sold to members of the general
public (just like a TV set, which has a similar exposure rate limit), and
such members of the public do not have to use or obtain any sort of
personnel dosimetry.  Lastly, I am not aware that any State actually
regulates such equipment in terms of requiring a State licensing permit or
an initial radiation survey by some qualified 'expert' etc.  Perhaps other
RADSAFERS can illuminate this point further.  I would surmise that few
States would have any radiation safety reason to be concerned about such
equipment, given the existence of the above described federal radiation
emission standard for such equipment.

REGARDS David

David W. Lee
Los Alamos National Laboratory
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:  (505) 667-8085
FAX: (505) 667-9726
lee_david_w@lanl.gov



At 02:31 AM 29-05-97 -0500, you wrote:
>Hi to alla radsafers!
>
>I'm interested in finding out if anybody of you is concerned in
>radiation safety in an airport.
>I was asked to evaluate the risk for the workers who manage and check
>radioactive parcels arriving by air and those working with RX baggage
checkers.
>Is anybody interested?
>
>Thanks, Mauro
>
>Mauro Campoleoni
>Health Physicist
>Istituti Clinici di Perfezionamento
>Via della Commenda, 12
>20122 - Milano, Italy, tel. 39-2-57992166
>trentino@iol.it
>Mauro_Campoleoni@rcm.inet.it
>
>
>
>
David W. Lee
Los Alamos National Laboratory
Radiation Protection Services Group (ESH-12)
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:   (505) 667-8085
FAX:  (505) 667-9726
lee_david_w@lanl.gov