Re: Individual Dose Monitoring Response

[rkathren@tricity.wsu.edu (Ron L. Kathren)]

Responding to the query posed by Bill Stephany:

The interactions of time, temperature and humidity on the latent image of a
photographic film usded for dosimetry are quite complex and also a function
of the emulsion itself.  There have been a large number of publications that
discuss the effects of environment on film badges, including the relatively
recent National Research Council publication "Film Badge Dosimetry in
Atmospheric Nuclear Tests" (1989) which provides a very good summary.  Also,
check Chapter 5 Volume II of "The Dosimetry of Ionizing Radiation" edited by
Kase, Bjarngard and Attix, and its predecessors, Attix, Tochilin and Roesch
and Hine and Brownell.  

Good CONSERVATIVE practice would suggest a wearing interval not to exceed
one month for film badges, especially if in a non-desert environment.  Some
measure of protection can be afforded by sealing the films in thin
polyethylene pouches.  Longer wearing intervals -- eg quarterly -- in humid
environments may be legally indefensible.

TLDs are generall unaffected by envirnmental conditions except for VERY high
temperatures which may cause some loss of signal from low temperature traps;
possible response to visible light; and some fading of signal which
primarily occurs right after exposure but which is usually not a practical
problem with LiF and other commonly used TLD's.

Please feel free to call me (509-375-5643) if I ccan be of further help;
this is an area that is near and dear to my heart (undamaged portions!).

Ron Kathren


 At 08:04 AM 10/22/97 -0500, Bill Stephany wrote:
>RADSAFERS,
>
>We process film badges and TLDs monthly, one reason being a concern
>about the quality of latent image retention in the undeveloped film badges.
>Likewise, I wouldn't leave a roll of photographic film undeveloped for six
>months if it might contain important pictures.  I'd appreciate knowing
>whether or not this concern is valid.
>
>Bill Stephany
>Assistant RSO
>Medical College of Georgia
>fiss.bstephan@mail.mcg.edu
>
>