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

Thu Nov 3 10:59:41 CDT 2011

OK.  Now all you have to do to prove your point is give some evidence
that U238 has an interaction cross-section that is sufficiently larger
than other atoms that are in a cell that it makes a difference, and then
calculate how high the concentration of the uranium isotopic mix in DU
it would take to at least equal the higher activity of U(nat), keeping
in mind that the uranium atoms in U(nat) also have the same
photoelectric cross-section, and that the higher activity in U(nat) is
mostly alpha, which has a higher quality factor.  

And yes, these calculations are yours to do, as you are the one
defending the position that DU is more radiologically toxic than
non-depleted uranium.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Busby, Chris
Sent: Thursday, November 03, 2011 3:00 AM
To: The International Radiation Protection (Health Physics) Mailing
List; The International Radiation Protection (Health Physics)
MailingList
Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U

It turns it into photoelectrons which are exactly the same as beta
particles. Thats waht it does with it. Its in the physics books if you
have one handy.
C

-----Original Message-----
From: radsafe-bounces at agni.phys.iit.edu on behalf of Brennan, Mike
(DOH)
Sent: Wed 02/11/2011 23:28
To: The International Radiation Protection (Health Physics) MailingList
Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U

I am afraid you are wrong, in several different and obvious ways.  

The first is that, if you actually read my post, you will see that I
specified "by weight or per atom", so that someone wouldn't try
comparing apples and inverse-apples.  Let's stick with the kind of units
that are used, like Bq/g or Bq/atom or ug (U)/g, or something like that,
rather than atoms/Bq, shall we?  Comparing radiological toxicity really
has to be done on a by weight (or mass) or on a per atom basis, unless
one is claiming that a particular decay scheme (type of decay and
energy) is more toxic than another (one that might be brought up, but in
comparing DU to U(nat) or even slightly enriched U fails on other
grounds).

As far as your greater number of atoms of U238 absorbing a greater
percent of the natural background gamma flux (and doing what, with it,
exactly?  Re-radiating it?  Turning it into heat?  What is it doing that
would damage a cell?), than the same activity of U(nat), I submit that
the ratio of interest is not atoms DU compared to U(nat), but rather
each of them as a percentage of the number of atoms in the volume of
interest (I will assume a cell, as this all becomes fairly pointless if
we are just talking about chunks of metal).  As the percentage of atoms
in a cell that are uranium is vanishingly small (unless you have
flat-out poisoned the cell with the heavy metal, in which case the rad
becomes moot), the difference between the gammas absorbed by the two
flavors of U are also vanishingly small.  

Another error you make is assuming that only in DU does U238 decay.  In
U(nat) and even enriched U (until you reach quite high enrichment
ratios), there is plenty of U238 to undergo decay.  In U(nat), for
example, about 99% (by mass) is U238.  But wait, there's more!  If you
are going to include U238 decay products in the activity of DU (not at
all unreasonable, in my opinion), then it is only reasonable that
everything found in U(nat) be included, also.  Means not only Th234 and
Pa234, but also U234, Th230, Ra226, all in secular equilibrium, and some
percentage of everything further down the chain, depending on how much
of the produced Rn222 wandered off before decaying.  So even if you
started with a greater number of atoms of U238 than atoms of uranium in
U(nat), when you add in the decay products that can reasonably be
assumed to be present, there is a lot more activity from the U(nat).  If
you want to talk about U(nat) as refined rather than ore, then you STILL
have the activity of the U238 decay products, PLUS equal activity of
U234, Plus the activity of U235, and however much of their decay
products have built up.

I actually agree that it is no big deal, which is why I dismiss the "DU
causes (fill in the blank), especially when the "evidence" cited is
poor, suspect, nonexistent, or actually contradictory.  

And I strive to be careful, which in this biz is mostly about being
knowledgeable an intellectually honest.   

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Busby, Chris
Sent: Wednesday, November 02, 2011 3:01 PM
To: The International Radiation Protection (Health Physics) Mailing
List; The International Radiation Protection (Health Physics)
MailingList
Subject: Re: [ RadSafe ] DU not toxicologically identical to non D-U

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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