Re: Individual Dose Monitoring

["Sandy Perle" <sandyfl@ix.netcom.com>]

Ron Kathren stated the following:

> Given the well documented environmental (eg latent image instability)
> problems with films used in the field for long intervals, I would be quite
> reluctant to have a wearing or field exposure interval for film dosimeters
> of longer than 1 month; for TLD, 6 months or even years may be fine.  Some
> sites (eg Hanford) utilize a single TLD as a backup or as a long term
> 'lifetime' dosimeter for nonradiation workers.

I agree with Ron's statements. It is still important to note that 
with good practices (relying on the wearer and their facility) 
excellent film results can be obtained for periods up to 6 months. In 
this time frame, with proper controls, fogging of the film, as well 
as other factors, heat, moisture and misuse, can be minimized. As 
stated, I personally recommend that film should be processed on a 
monthly basis and TLD on a quarterly basis. Even TLD has issues with 
fading and other characterstic factors that can reduce the overall 
confidence level, which is highly dependent on the type of TLD, 
phosphor, etc.

------------------
Sandy Perle
Technical Director
ICN Dosimetry Division
Costa Mesa, CA 92626
Office: (800) 548-5100 x2306 
Fax:    (714) 668-3149
  
sandyfl@ix.netcom.com
sperle@icnpharm.com

ICN Dosimetry Website:
http://www.dosimetry.com

Personal Homepage:
http://www.geocities.com/CapeCanaveral/1205

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