Kenneth Piers's calculations support the point I made in my responses to
John Burgeson and Charles Carrigan that DU is not likely a radiological
hazard but, possibly, a chemically toxic material. As I mentioned, an
autopsy of a Canadian soldier who was involved in either the Gulf War of the
Bosnian/Croatian/Kosovan activities reportedly showed "elevated levels of
DU" however those were determined.
I agree with Piers that the uranium oxides would not likely be airborne very
long (the specific gravity of U3O8 is ~8.3) but the particles would likely
be very small (when UO2 is oxidized to U3O8, it undergoes a volume
expansion) and would have a large surface area to mass ratio. If the
autopsy results are correct (they were reported in the media) there must
have been some biological pathway that would have allowed the body to absorb
the uranium.
Chuck Vandergraaf
-----Original Message-----
From: Kenneth Piers [mailto:Pier@calvin.edu]
Sent: Monday February 26, 2001 7:19 AM
To: asa@calvin.edu
Subject: RE: DU (Depleted Uranium)
A rough calculation using first order decay kinetics and a half life of
4.5e9 years for U-238 shows that if an individual ingested some depleted
uranium and if all of it remained in his body for a period of 10 years
less than 2e-7% of the uranium would undergone radioactive decay. It is
true that the decay of a U-238 particle to Pb-206 liberates about 8
alpha particles 6 betas, and 7 gammas. Evens, given the exceedingly low
radioactivity of the U-238 itself, it seems unlikely that the DU would
pose a radioactivity hazard toward anyone.
And if some of the DU were vaporized during its use in combat
materials, I wonder how long the oxides would remain airborne, given the
mass of the uranium oxide particles. Likely these would settle out of
the atmosphere in relatively short time and therefore would not pose any
long-term inhalation hazard either.
And if some food materials (say leafy vegetables) coated with DU oxide
dust (note that washing the food materials prior to eating would likely
remove the offending material) were ingested, how readily would these
oxide particles be solubilized in the digestion process? The oxides
would be expected to dissolve in acids, but generally such solubility
requires the use of acid of greater concentration than stomach acid
(usually 6 M or greater). Do these oxides dissolve readily in 0.1 M
hydrochloric acid ( the approximate acidity of stomach acid)? If not,
there would be a high probability of these oxides simply being swept
through the system with little health effect.
In short, while I am no fan of military action, and am sympathetic to
the plight of all civilians and military personnel affected by such
activities, It seems unlikely to me that DU poses a serious health
threat.
kp
This archive was generated by hypermail 2b29 : Mon Feb 26 2001 - 10:08:25 EST