From: ntaib@silver.ucs.indiana.edu (Iskandar Taib)
Subject: Re: Tracers
Organization: Indiana University
Date: Fri, 21 Aug 1992 13:22:36 GMT


From ntaib@silver.ucs.indiana.edu (Iskandar Taib)

In article <BszLFI.FrF@lawday.DaytonOH.NCR.COM> viking@iastate.edu (Dan Sorenson) writes:

>ntaib@silver.ucs.indiana.edu (Iskandar Taib) writes:

||Uranium is pretty darned toxic if it gets loose, both
||chemically (as a heavy metal) and because its radioactive
||to some degree. The radioactivity might not harm you from
||just being around the ammunition, but if you ingested it 
||it might get absorbed into the body, where it will sit and 
||irradiate your tissues for years to come.

|	U238, which is what DU is (though some other isotopes exist at a
|fraction of a percentage) is less radioactive than the raw ore is.  If it
|is inhaled it's pretty good odds of lung cancer, but since it tends to
|react with water I cannot think the radiation would be a big concern for
|injestion.  Despite burning of the intestines, it would be expelled if
|the particle was too large to pass through the intestinal walls.  With
|injesting lead, my understanding is that it is absorbed and will become
|a large factor in your life expectancy from lead poisioning.  I must me
|missing something still.  Radiologically, it's only a hazard if you
|get it lodged in your lungs.  There's got to me more to this.  Does
|anybody know if a particle will be broken down and injested if it
|managed to get inside your intestines?

Actually both uranium and lead can react with water. Uranium tends to 
form a 6+ or 9+ ion (I'll have to check) but the size of the ion 
shouldn't be "too large to pass through intestinal walls". Large ions 
such as chloride can pass through intestinal walls and heavy metal 
cations are generally tiny compared to anions. My guess is that it 
behaves mostly like lead..it will get absorbed into the bloodstream, 
and since there isn't much use for it it will either get excreted 
over time or stored in bone. Treatment would probably be like that 
for lead poisoning: large doses of chelating agents like EDTA. Whe-
ther or not Uranium becomes soluble in the digestive system depends 
on Eh and pH conditions in the digestive tract, and the formation of 
soluble vs. non-soluble ions under various Eh-pH conditions. My guess 
is it will be pretty mobile since the digestive tract is pretty aci-
dic and oxidizing, and most heavy metals are mobile under such con-
ditions (take acid mine drainage as an example). 

It could be worse.. there are nuclides like ^90^Sr that can replace
Calcium in your bones, which makes it many times more easily ab-
sorbed. Right after Chernobyl they were giving children doses of 
iodine in Poland because one of the byproducts of nuclear fission 
they were worried about was a radioactive isotope of iodine. The 
nonradiogenic iodine in the medicine bottle would swamp the radio-
active iodine that might be picked up by the kids from the air or
from food in the fallout zone so a lot less of the bad stuff would 
get absorbed by the thyroid gland. 

I suspect ^238^U is less radioactive than Uranium ore not because 
Uranium ore has ^235^U in it but because there are other highly 
radioactive nuclides present, eg. Radium. The Curies were alerted
to the presence of Radium because Uranium ore (pitchblende in this 
case) was a lot more radioactive than can be explained by Uranium 
alone. Remember that ^235^U makes up a tiny amount of the total 
Uranium present, and that the reason why it is so desirable is be-
cause it is _easily_fissionable_, not _more_radioactive_. (It might
be a little more radioactive, at least as a neutron emitter, than 
^238^U since it does fission more).

Where are all those nuclear bomb experts that posted here a year 
or so ago?  9-)
-- 
-------------------------------------------------------------------------------
Iskandar Taib                          | The only thing worse than Peach ala
Internet: NTAIB@SILVER.UCS.INDIANA.EDU |    Frog is Frog ala Peach
Bitnet:   NTAIB@IUBACS                 !

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