Re: Deadly Plutonium ?

[Franz Schoenhofer <schoenho@via.at>]

At 13:10 07.02.2000 -0600, you wrote:
>Joseph and Others,
>I always had an impression that Pu-239 has more toxic damaging health
effects 
>than its radiation damage abilities. Wouldn't be a person lethally poisoned 
>faster then die from the radiation damages? I believe, that PU-239 AIL is 
>based on its toxicity.
>So then Joseph, you are right that alpha from Uranium or Pu are still alphas 
>and they have the same LETs. I do not remember the exact energies but I
think 
>they are very close.
>Please, correct me if I am wrong.
>Emil.
>kerembaev@cs.com
>

Generally speaking an alpha-ray is an alpha-ray and an alpha from uranium
will, when emitted from a particle in the lung have almost the same effect
as an alpha from a plutonium particle. But an atom (or rather ion) is not
an ion..... Uranium and plutonium behave chemically differently and so do
all other radionuclides. As mentioned by others plutonium is rather
insoluble and will pass the GI tract relatively fast and will not enter the
body. Even this is not correct, because much depends on the oxidation state
of plutonium, whether it is easily soluble or not at all. A uranium oxide
or carbide particle is insoluble, but depending on oxidation state and pH
other compounds might be easily soluble. Furthermore there is a big
difference between radionuclides and their effect in the body whith regard
to possible accumulation in certain organs. Cs-137 is accumulated in muscle
tissue, but also excreted with a certain biological half life. Sr-90 and
Ra-226 for instance are accumulated in bones. As far as I remember uranium
is accumulated in the kidney (or was it liver?) - please correct me if I am
wrong. 

ALIs are given for radiological risks. Especially for uranium the
chemotoxicity is by far greater than the radiotoxicity for soluble uranium.
Unfortunately to my knowledge no country on earth has until now dared to
set weight concentration based limits for uranium in drinking water. I
think to remember that the EPA has proposed a limit of 20 microgram per
liter, but no limit seems to be in force. The European Union explicitely
states that the limit for uranium in drinking water does not take into
account the chemical toxicity. I am not absolutely sure that it is the same
case for plutonium, but it might easily be.

Franz


Franz Schoenhofer
Habicherg. 31/7
A-1160 Vienna
Austria
Tel.: +43-1-495 53 08
Fax.: same number
mobile phone: +43-664-338 0 333
e-mail: schoenho@via.at

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