Re: incorporation measurements

[carol marcus <csmarcus@ucla.edu>]

At 07:14 PM 10/25/99 -0500, you wrote:
>In a message dated 10/25/1999 4:44:59 PM Pacific Daylight Time, 
>schoenho@via.at writes:
>
><< Since we do not want to "invent the wheel again" I wonder whether
> regulations or recommendations exist in other countries or from
> international organisations regarding the maximum permissible
> incorporation, the control methods and especially the control intervals and
> frequencies for short-lived radionuclides. In this context especially
> Tc-99m is of concern, but even the definition of "short-lived" may pose
> some problems. F-18 and C-11 sure are short lived and most probably
> incorporation of personnel can hardly checked, but do you regard tritium
> with a biological half-life of about 10 days as shortlived? How about
> Tl-201 etc.?  >>
>
>Maybe I'm misunderstanding the question, but title 10 of the Code of Federal 
>Regulations, part 20, Appendix B does just this, I think.  It lists for each 
>nuclide, the Annual Limit of Intake (ALI), based on the biological models 
>described in ICRP 30.  The ALI for Tc-99m, for example is 200 mCi through 
>inhalation and 80 millicuries through ingestion.
>
>Barbara L. Hamrick
>BLHamrick@aol.com
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Dear Radsafers:

Contrary to certain erroneous opinions, we do not use "open sources" in
nuclear medicine.  No intravenous medicines are openly manipulated, or
sterility would become a problem (a lot more important problem than the
radioactive nature of the drugs).  While both EPA and NRC do not understand
this, probably because neither agency knows anything about medicine or
pharmacy, it is nevertheless true.  Generators are closed systems, and so
are kits and vials.  

The only exception has to do with oral meds, and sodium iodide is
essentially the only one (except for C-14 urea capsules, which NRC
essentially completely deregulated). When patients drink NaI-131, they don't
swig it from a shot glass.  They sip it through a straw attached to a
needle, which is what enters the sealed vial.  Another strawlike device with
a needle is used to add water to "clean out" the vial so that the patient
gets most of the contents.  A third needle is added as an air bleed, so that
the pressure inside the vial equalizes.  The solution is made basic, so that
volatility is negligible.  As I have described to this group before, the
only time we had a problem was when the NRC forbade pharmacists and
physicians from stabilizing the solution against volatilty, because NRC did
not understand what it was doing.  This was solved with a petition known as
the "Radiopharmacy Rule", which was basically a five year exercise in
vicious warfare, even though NRC asked me to write the petition and assigned
the group leader of the medical section to help me.  There were measurable
levels of inhaled I-131 while the NRC prevailed.  There was none before or
since.  

NaI-131 and NaI-123 are also available in capsules, and due to pH
adjustments, are also insignificantly volatile.  

Barbara Hamrick is, of course, completely correct.  10CFR Part 20 covers
this in any case.

American nuclear medicine has delivered about a third of a BILLION doses of
radiopharmaceuticals to patients throughout its history.  Would anyone like
to list the sum total of significant cases of internal contamination to
workers in this medical and pharmacy specialty?

In other words, I think people should quit inventing nonexistent "problems"
to solve.  In NRC's "Scientech Report" (comment deadline for this 900 page
nonsense ended 10/25/99), it talks about risks to workers in nuclear
medicine from inhalation, ingestion, and clouds of radioactivity.
Obviously, the staff and management of NRC are trying to fool the
Commissioners, which I guess is not 
very hard.  In any case, it's poppycock.  THERE ARE NO DATA INDICATING A
PROBLEM.  As nuclear medicine has been practiced in this country for 63
years, I think that that's enough time to construct a data base.  NONE EXISTS.

Ciao, Carol

Carol S. Marcus, Ph.D., M.D.
<csmarcus@ucla.edu>

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