Re: airborne U

["schoenho" <schoenho@via.at>]

Schoenhofer
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A-1160 Wien
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e-mail: schoenho@via.at

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> Von: Al Tschaeche <antatnsu@pacbell.net>
> An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Betreff: Re: airborne U
> Datum: Freitag, 01. August 1997 21:20
> 
> Otto G. Raabe wrote:
> > 
> > July 23, 1997
> > 
> > Dear Mike:
> > 
> > Calculation of radiological risks from pure U-238 is meaningless since
the
> > actual risk depends on the chemical toxicity of uranium in the kidney
not in
> > the bone or lung, although both the bone and lung can be a reservoir of
this
> > potentially toxic element.
> 
> Otto, Mike, You bring up an interesting, to me, question.  We all know
> that U-238 or natural uranium and uranium enriched to about 5% is a
> chemical toxicant, not a radiological one.  And the organ at risk is the
> kidney.  All of the DACs, MPCs, etc. for such material make that
> assumption.  But, if one has class Y uranium, what is the effect on the
> lung of a large mass of uranium in the lung that would be necessary
> before the kidney becomes a problem because of translocation of the
> uranium from the lung?  In other words, is the kidney really the organ
> of concern for such uranium or might there be some lung problem just
> because there is so much mass of uranium in the lung, a chemical, not
> radiological, problem?


Al and fellow RADSAFERS,

It is clear, that uranium is - when ingested - much more chemotoxic than
radiotoxic. I heard some rumors, that the EPA proposes a limit of 30 ng per
liter of drinking water as a limit. Can anybody confirm this? Does anybody
know about regulations on existing uranium activity and mass concentrations
in drinking water in other countries? The European Union is in the state of
proposing a new guideline for drinking water contaminants - the proposal
does not contain any values for activity concentrations for radionuclides
and not either a limit for uranium on a mass concentration basis. 

For the question of inhalation there must be regulations for the uranium
industry. It might be that uranium is dissolved fast in the lung fluids -
but I am no expert in this field. I am not even a CHP, not a member of the
HPS,.........

Franz