[ RadSafe ] DU not toxicologically identical to non D-U

Brennan, Mike (DOH) Mike.Brennan at DOH.WA.GOV
Mon Nov 7 11:17:43 CST 2011


But we are not discussing pure U235: we are discussing the difference
between DU and non-depleted uranium, U(nat) being the obvious choice, as
the that is what people are exposed to (while acknowledging that the
isotopic mix in U(nat) varies within a range).  The specific activity of
U238 is a little less than half that of U(nat), which means that for a
given unit of activity there would be about twice the number of U238
atoms than U(nat) atoms.  You are now in the position of arguing that
twice the photoelectron dose is significant against the background of
all dose from all sources.

I do not accept your attempted sleight of hand in trying to use U235 as
the comparison, as no one, not even you, has claimed that pure U235 has
been used in weapons (other than atomic weapons, and I hope we are in
agreement that none of those were used in Iraq without anyone noticing).
As I have pointed out on several occasions, U(nat) and even most forms
of enriched uranium are mostly U238.  




-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Busby, Chris
Sent: Friday, November 04, 2011 12:06 PM
To: Witold Matysiak; The International Radiation Protection (Health
Physics) Mailing List
Cc: C.Busby at ulster.ac.uk
Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U

You are missing the point. There are more atoms of U238 per unit dose
than atoms of U235. So comparison on a dose basis (which was what
started this discussion)is not the point. Both have the same
photoelectron emission buthete will be more photoelectrons because there
is more U238 for teh same dose.
Chris


-----Original Message-----
From: Witold Matysiak [mailto:matysiw at mcmaster.ca]
Sent: Thu 03/11/2011 16:39
To: The International Radiation Protection (Health Physics) Mailing List
Cc: C.Busby at ulster.ac.uk
Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U
 
On Wed, Nov 2, 2011 at 6:00 PM, Busby, Chris <C.Busby at ulster.ac.uk>
wrote:
"Uranium absorbs natural background gamma radiation on the basis of its
high atomic number, the photoelectron flux at the position of the
uranium
is greater, dose for dose, U238 that U235 since there"

I may be missing the point here, but U238 and U235 have the same atomic
numbers so based on the standard theory photoelectric cross-sections are
equal for both.
What effects related with mass number should be included in PE
X-section?


On Wed, Nov 2, 2011 at 6:00 PM, Busby, Chris <C.Busby at ulster.ac.uk>
wrote:

> There is such a way. Since U238 is slightly less intrinsically
radioactive
> than U235, the quantity of U238 per Becquerel is greater, so for the
same
> implicit activity (alpha decay of the parent nuclide) there are more
atoms
> of Uranium in the same calculated dose from teh U.  Since Uranium
absorbs
> natural background gamma radiation on the basis of its high atomic
number,
> the photoelectron flux at the position of the uranium is greater, dose
for
> dose, U238 that U235 since there are more atoms.
> Furthemore, you havent taken into consideration the daughter nuclides,
the
> betas from Pa234m and Th234, two betas before U234. In the case of
U235
> there is only Th231, one beta. Therefore the total dose, U238 + two
fast
> daughters is greater than U235 +1 fast daughter.
> Hows that?
> I mean its no big deal, but you do have to be careful here.
> Chris
>
>
>
> -----Original Message-----
> From: radsafe-bounces at agni.phys.iit.edu on behalf of Brennan, Mike
(DOH)
> Sent: Mon 31/10/2011 18:30
> To: The International Radiation Protection (Health Physics)
MailingList
> Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U
>
> James,
>
> While I can see an argument that DU is LESS toxic, radiologically,
than
> uranium that has not had the shortest half-life, and thus highest
> specific activity, isotopes removed, I assume that is not what you
wish
> to imply.  If you have an argument for how something with a lower
> activity (by weight or per atom) is more toxic, I would be interested.
> If you are saying that the chemical properties of U238 are
sufficiently
> different from those of U235 and U234 as to be detectable in the way
> organisms are affected, I would like to see the model and the
evidence.
>
>
> I do, however, see a problem with you citing evidence, as your record
of
> citing relevant items that actually support your position is not good.
>
> -----Original Message-----
> From: radsafe-bounces at health.phys.iit.edu
> [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of James
Salsman
> Sent: Monday, October 31, 2011 10:35 AM
> To: radsafe at health.phys.iit.edu
> Subject: [ RadSafe ] DU not toxicologically identical to non D-U
>
> Mark Sonter wrote:
>
> > DU *must* be toxicologically identical to non D-U.
>
> That is not consistent with the translocation graph shown in the
> Gmelin Handbook of Inorganic Chemistry, 8th Edition, English
> translation (Springer-Verlag, 1982), Title U -- Uranium, Supplemental
> Volume A7 -- Biology, Section 3 -- Metabolism: Absorption, page 305,
> Figure 3-1, "Retention and translocation of inhaled uranyl nitrate,"
> from J.E. Ballou, R.A. Gies, and N.A. Wagman in BNWL-2500, Part 1, pp.
> 379-380 (1978.)
>
> If I owe Bob Cherry an apology for not knowing about genotoxicity when
> he made statements to federal officials on the health aspects of
> uranium fume inhalation, or for getting his title wrong, then I
> apologize.  I remain of the opinion that a more appropriate title
> would involve a Quantico detainee number for decades followed by
> "Defendant" in a medical expense loss recovery class action suit, and
> I appreciate all the work the military does to defend my right to
> express such opinions.
>
> Sincerely,
> James Salsman
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