Re: Iodine Bioassay: NUREG/CR-4884

["Charles Potter" <CAPOTTE@sandia.gov>]

---------------------------- Forwarded with Changes ---------------------------
From: Charles Potter at PO821CC1
Date: 5/8/96 10:10AM
To: Ccja@aol.com at hubsmtp
Subject: Re: Iodine Bioassay: NUREG/CR-4884
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     I sent this to the person who sent the original message, but in the 
     name of global interest (re:  Sue Dupre) I figured I'd forward it to 
     the whole list.
     
     Fire away.
     
     Gus Potter
     Sandia National Laboratories
     CAPOTTE@sandia.gov
     (505) 844-2750


______________________________ Forward Header __________________________________
Subject: Re: Iodine Bioassay: NUREG/CR-4884
Author:  Charles Potter at PO821CC1
Date:    5/8/96 10:10 AM


     For iodine, the f1=1, meaning all iodine in the stomach goes 
     immediately to the systemic whole body, and the only inhalation class 
     is class D meaning that there is no long term lung retention.  Since 
     this is the case, the inhalation and ingestion models act the same 
     (after a few days after intake) except for the 37% exhalation that is 
     assumed in the lung model.  Therefore, you should just be able to 
     multiply the ingestion IRFs by 0.37 to get those from inhalation.  To 
     account for the radioactive isotopes, you can just multiply by the 
     decay factor.
     
     Good luck,
     
     Gus Potter
     Sandia National Laboratories
     CAPOTTE@sandia.gov
     
     
______________________________ Reply Separator _________________________________
Subject: Iodine Bioassay: NUREG/CR-4884
Author:  Ccja@aol.com at hubsmtp
Date:    5/7/96 6:25 PM
     
     
Most people, I believe, monitor for occupational internal dose commitments, 
by the iodines, by in vivo bioassay, i.e., gamma counting of the thyroid. 
This Nureg only gives the IRF's for the stable I-127, in the thyroid, for the 
ingestional mode of intake. This is an unfortunate oversight, in a generally 
very useful document. Since the CDE's are significantly different for 
inhalation (~40% less), if one were to use this document to compute them, one 
would have to correct, for decay, the values given for the IRF's for one of 
the radioiodines (I-131 being the easiest). Otherwise, another source of 
error is introduced into an already dicey situation.