[ RadSafe ] Fwd: ruling out uranium vapor with x-rays

[Dave Blaine]

Mike, thank you again for not dismissing my concerns out of hand.

Of course you are right that there are several metal and metal oxide
vapors which pose serious hazards and which, like mercury and lead
vapors, remain in vapor state longer than people initially anticipated.
However, these problems are usually spread out evenly among the
population, and not concentrated in battle zones where personnel and
civilians have a greater risk of suffering a clinical toxicant exposure.

> Like many compounds that are gaseous or airborne
> when created in a fire, as they cool they settle out, plate onto
> surfaces, undergo further chemical reactions, etc., and cease being
> airborne.  What percentage of the UO3 produced will remain in a vapor
> state when the combustion products have cooled to environmental
> temperatures?

Very little, but the sub-0.01 micron particles are still a major component.

Refering to Figure 2 on page 4 of Guilmette and Parkhurst (2007) --
  http://rpd.oxfordjournals.org/cgi/content/abstract/ncm359v1
-- the trend shows clear evidence of substantial quantities of smaller
particles from the inhalation estimation samples they took.

> Also, at what concentration do you believe gaseous UO3 is no longer?

500 seconds after a burn 20% of the uranium will be in particles less than
0.01 micron mean diameter, in open air 5 m over the ground surface with
5 m/s wind.

>  Are you part of an anti-armored vehicle campaign?

No. I think DU makes good armor, but not so much against opponents
with DU munitions who can ignite it.

> > Every professional who studied the issue of uranium inhalation --
> > including who who I know to be on Radsafe -- has either completely
> > omitted any mention of uranium genotoxicity in their publications on the
> > subject admitted specifically that they never considered it in preparing
> > their conclusions.

I meant to say, "until 2004 (except for the Navy Toxicology Detachment)"
in that sentence," and, "subject OR admitted."

> I must have missed something:  What condensate?  I thought the
> contention was that UO3 remained in a vapor state, available to be
> breathed.

The condensate per Guilmette and Parkhurst represents the amount that
the lungs of people downwind would be exposed to.

> As for counting alphas; sure, have at it.  Alpha counters aren't that
> expensive.  Be sure to account for radon daughter products and naturally
> occurring uranium in the environment.  Maintain good chain of custody,
>and use techniques that others can reproduce.

I wish.  I am asking others, but you know if someone like me tried
to run that there, would likely be local newspaper headlines about the
FARC radical conspirator who was planning a dirty bomb. :(

I would LOVE to burn a gram of DU with 30 squares of double-sided tape
at various distances and orientations which I could remove and cover with
some alpha-sensitive photodetector film after a fixed exposure time,
because the gas diffusion of small particles is well understood.

James Salsman, as Dave Blane pseudonomously

P.S.  About pseudonyms:  The DU controversy evokes strong emotions on
both sides of the debate. It is often useful to have a clean emotional
state when addressing the issue with people who have formed
preconceptions about the issue or the people discussing it in the
past.