Re: progeny nuclides and ALI/DAC

["Otto G. Raabe" <ograabe@ucdavis.edu>]

>X-POP3-Rcpt: fzraabe@sol
>X-Sender: kfe@cosmail5.ctd.ornl.gov
>Date: Mon, 16 Nov 1998 09:23:40 -0500
>To: "Otto G. Raabe" <ograabe@ucdavis.edu>
>From: Keith Eckerman <kfe@ornl.gov>
>Subject: Re: progeny nuclides and ALI/DAC
>
>Dear Otto,
>
>In answer to the RADSAFE question:>
>>>
>>>
>>>Can anyone tell me if dose from progeny nuclides are included in the FGR 11
>>>ALI and DAC numbers?  I am going through some Ra-226 calculations and would
>>>like to know if these must be repeated for each downstream nuclide.  I have
>>>looked through the introductory matter in FGR 11 and have also looked
>>>through ICRP 30 but have been unable to make this determination.  
>>>
>>>If the information is there and I have just missed it, please accept my
>>>apologies in advance.
>>>
>
>The ingrowth, during the commitment period, of radioactive daughter
>products (progeny) formed within the body following the intake of the pure
>parent is considered in the calculating the ALI and DAC.  This is
>consistent with the practice in Publication 2 in setting the MPCs.  The
>treatment is discussed in Sect. 4.6.1 of Publication 30 (see also Eqn 4.5).
> Some caveats regarding the ICRP-30 approach can be found in Sect 9.4.
>Information on the number of nuclear transformations of each chain member
>during the commitment period and their SEEs are given in the Supplements to
>ICRP-30.  In recent publication (ICRP-56, 67, and 69) ICRP has, in many
>cases - including Ra-226, assigned the daughter products independent
>kinetics.  
>
>Note the approach makes no assumptions regarding the nature of the intake.
>If members of the decay chain are present in the intake then the intake of
>each member should be considered separately.  In practice, the dose
>contribution from intake of very short-lived members is generally
>insignificant relative to that of the longer-lived parent.  Thus for
>example, one need not consider the ingestion of Po-218 but should not
>dismiss the ingestion Pb-210 in all instances.  As we know, inhalation here
>is a different story.
>
>I can provide you numerical data regarding the details of these
>calculations etc.  Unless you are specifically interest in the
>ICRP-30/FGR-11 era then I would suggest that you consider the later ICRP
>efforts. If I can be of help let me know.
>
>Regards,
>
>Keith
>
>Keith F. Eckerman, Ph.D.			Voice	(423)574-6251
>Oak Ridge National Laboratory			Fax 	(423)574-1778
>1060 Commerce Park				e-mail	kfe@ornl.gov
>Oak Ridge, TN 37830-6480
***************************************************************************

		*****************************************************
		Prof. Otto G. Raabe, Ph.D., CHP
              Institute of Toxicology & Environmental Health (ITEH)
		     (Street address: Old Davis Road)
		University of California, Davis, CA 95616
		Phone: 530-752-7754  FAX: 530-758-6140
		E-mail ograabe@ucdavis.edu
              *****************************************************
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