Re: DU - request for scientific (!) information

[Mark Sonter <sonter@camtech.net.au>]

Regarding Depleted Uranium and its alleged hazards:

Inhalation of Depleted Uranium fume is not too different from exposure to
respirable uranium oxide as ore dust in uranium mining, altho' the particle size
will be in the one case some 50 to 100 nanometres and in the other some few
micrometres AMAD.

Radiation risk in uranium miners and 'millers', i.e., treatment plant operators,
has been studied for many years. We know that these people are exposed by four
main pathways, namely, radon progeny inhalation dose to the lung (serious
concern and requirement for active control in underground mines); gamma whole
body irradiation (only of significance and requiring active control in high
grade (i.e., 0.5% U3O8 ore or more); and committed doses from inhalation of
radioactive ore and/or product dusts; and from  ingestion of ore and/or product
dusts. By far the main contribution to the committed dose comes from the thorium
230 and the radium 226, rather than the uranium 238, 234, or 235 (you can look
up the sieverts per becquerel DCF in IAEA publ 115, or elsewhere).

We were always taught that the uranium hazard was primarily (?solely) a chemical
heavy metal hazard, namely non-specific heavy metal denaturing of protein
molecules, and that the kidney was the main organ at risk, basically because of
the large blood flow through it.

The point of this essay?? - To the best of my understanding, there has never
been any indication of 'uranium-poisoning' in the uranium extraction (mining and
milling) industry, nor any indication of epidemiologically enhanced kidney
problems, despite what I know must have been significant airborne uranium
exposures in the early uranium mining industry, at levels and for periods much,
much, much greater than could have occurred in either Kosovo or the Gulf.

I do have recollections of workers with enhanced uranium-in-urine results, from
occasional exposures to spillages of ammonium diuranate feed (soluble, of
course) and uranium oxide product, in the calciner section of the Mary Kathleen
Uranium mine where I worked 20+ years ago. The airborne levels (total, i.e.,
open-faced filter) during the upsets might have got to (say) a fraction of a
milligram per m3; the U-in-urine figures would then go to 100 or 200 micrograms
per litre urine, and then return to normal over a period of a few weeks.

In conclusion, I would think the idea of a significant radiation dose from DU
fume from munitions to be almost unbelievable. If such a dose were received, one
should see kidney failure.

Mark Sonter


Since I work for myself, these opinions ARE the opinions of my employer! HAH!



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