Re: Request for Info on DU Munitions

["Franz Schoenhofer" <franz.schoenhofer@chello.at>]

-----Ursprüngliche Nachricht-----
Von: Bob and/or Kathleen <kmca@mediaone.net>
An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Datum: Donnerstag, 11. Jänner 2001 01:51
Betreff: Request for Info on DU Munitions


>Dear Radsafers,
>
>Regarding discussions on DU munitions, and whether they may cause health
>effects to individuals, I was wondering if someone on this list could
please
>direct me to research and/or investigations performed to determine the
>byproduct constituents from burning/heat vaporizing DU similar to that used
>in munitions tips, and protocols used to determine if these byproducts are
>more or less biologically active than the DU solids themselves.

I am far from being a specialist in uranium, but my background is
radiochemistry, so I hope I can give you some information in answer to your
questions. Do not expect some special investigations and research, I rather
want to point towards common sense and some facts related to chemistry.

(Depleted) Uranium is used in munition because of its extremely high density
and therefore its penetrating power. It is used in metallic form. On impact
the kinetic energy is partially transformed into thermal energy, which
causes the uranium - which is anyway pyrophoric, which means that it easily
reacts with the oxygen from air - to ignite. Uranium is therefore
(partially) oxidized to uranium oxide, which deposits as an extremely fine
powder. Uranium oxide(s) are not soluble in water. When such small particles
are inhaled after resuspension, they can deposit in the lung. The lung
fluids may dissolve extremely slowly the uranium oxide particles and uranium
is carried away in the body fluids. Part of it will be excreted, part of it
will be deposited in different organs of the body, the critical organ being
the kidney, as it is for other heavy metals. The health impact of uranium in
this case will be only related to its chemical toxicity
which is by far higher than the radiotoxicity.
In case that such particles would be ingested and not inhaled, the particles
will pass the body without being dissolved and without having any impact on
health.

I can conclude that the formation of uranium oxide will by far reduce any
possible health impact, because of the decrease in uptake.

Rests of uranium not being oxidized on impact exhibit very low radioactivity
and a negligible dose to people living in the vicinity, which includes
children playing close to it. You should note, that natural background
radiation might differ by almost orders of magnitude, depending on the
geological conditions of an area (for instance high uranium concentrations
in the underlying ground) and the elevation which determines the
contribution of cosmis rays. The use of x-ray and nuclear medicine
diagnostics will give the patient doses higher by several orders of
magnitude - and this is socially accepted. A manyfold increase of dose
during flight is as well accepted.


Maybe there
>is no relationship, but in considering all of the attention the topic is
>receiving, I couldn't help musing that some materials have very different
>chemical/biological effects based upon their physical manipulation.

Yes, this is correct, but the transition from elemental uranium to uranium
oxide lowers the effects.


 I
>confess that this may be totally inapplicable, and probably falls into the
>category of comparing apples with oranges, but an example that came to mind
>is plastics that are essentially biologically inert, or very
>chemically/biologically different, when ingested or inhaled as whole,
small,
>or even very finely divided dust particles, but with adequate heat applied,
>can disassociate into toxins (e.g., cyanides)

I do not know any plastic, which would yield cyanides (which ones?) on being
heated. As mentioned above, the transformation of metallic uranium to
uranium oxides actually decreases the toxicity - which is anyway not because
of radioactivity but because of the chemotoxicity.


I would
>appreciate becoming familiar with the research performed on the byproducts
>of burning/heat vaporized DU compounds used by the NATO forces, if for no
>other reason to confirm to friends and family outside the radiation
>protection community that they have been performed.

I am sorry that I cannot spend days to collect literature citations and
reports just to satisfy your wish to become familiar with the research. If
you are really interested in the topic, you can perform your own searches,
you may follow the links which have been cited extensively on RADSAFE during
the last week or so, you can search the RADSAFE archives - the topic has
been dealt with several times during the last years - and you can perform
internet searches on web sites of organisations involved in this topic. What
I would really recommend to discard are the "informations" provided with
mass media. Finally you could trust what I have written above, based on
several decades of work in radiation protection and radiochemistry and on
common sense.

With my best regards
Franz


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