[ RadSafe ] Tungsten Alloy Munitions Pose Unforeseen Threat -NIHresearch

[James Salsman]

Don Mercado wrote, in reply to:
 >
 > "Each 30 mm round of DU ordnance suspends on average about 60 grams
 > of elemental uranium in the form of various oxides in the air."
 >
 > *Each* round, or those which hit something and burn? Every round
 > that fires doesn't burn, some that do burn are buried in the ground
 > and produce no "inhalable particles", etc.

Right, each round has about 280 grams of metallic uranium, so based
on the percentage that burn when fired at a hard target times the
average fraction of metal consumed in those that do burn works out
to 20%, or 60 grams each.

 > ... And you STILL haven't answered the question of what dose the
 > inhaled particles deliver. "Multi-milligram quantities a km away"
 > mean nothing if there's no concentration figure. Take what
 > multi-milligram quantity and spread it over 20 cubic km and you
 > have nothing.

Even if you ignore uranium trioxide, which everyone except Salbu
et al. last year has, then you still get multimiligram resperable
quantities of U3O8 and UO2 dust at least 1200 meters downwind,
even in a fairly strong wind:  Mitsakou, et al., "Modeling the
Dispersion of Depleted Uranium Aerosol," Health Physics, vol. 84,
no. 4 (2003), pp. 538-544:  http://www.bovik.org/du/aerosol.pdf

And, I should point out that even if the "Estimate of the time zero
lung burden of depleted uranium in Persian Gulf War veterans by the
24-hour urinary excretion and exponential decay analysis," (Military
Medicine, vol. 168, no. 8 (2003), pp. 600-605) article in fact did
use a slower solubility factor than is actually the case, then the
actual inhalation exposure of the symptomatic patients is still just
0.34 mg for the UO2 and U3O8 oxides that they assumed were the only
products inhaled.  So in determining stand-off requirements, it will
not matter how much UO3(g) the victims do inhale, because the lung
clearance rate from the insoluble oxides is all that counts if you
assume that the uranyl inhalation takes place independently.  So even
if their actual total uranium exposure was much larger, if all you
have to go on are the insoluble oxides, then you can assume that you
don't want to get 0.34 mg of those, because that level of those
oxides yields symptoms, regardless of how much soluble oxide comes
along with that inhalation level.

Sincerely,
James Salsman