Re: Nuclear Weapons Material

In order to cause damage, alpha emitters like plutonium must come
  in intimate contact with a material, such as the tissues of your
  lungs or bones or the inside of your favorite memory chip.  A
  billionth of a gram of plutonium inhaled or swallowed is
  something to seriously worry about, but you can hold a lump of
  the stuff in your hand as long as it is covered with a leakproof
  cladding or vitrified into a ceramic.
  
  It is in this sense that plutonium is extremely toxic and
  hazardous to the environment, while at the same time not being
  particularly radioactive.  Heavy shielding is not required
  between you and it.
  
My understanding is that the heavy metal toxicity of Pu exceeds
the radioactive toxicity by several (10?) orders of magnitude.  In
other words, the fact that Pu is an alpha emitter is irrelevant
to the risk -- it's simply like lead poisoning only several
billion times worse.

Simple arithmetic yields that the amount of alpha exposure from
a billionth of a gram of an alpha emitter with a half-life measured
in thousands of years is infinitismal.

	- kitten

Patrick Juola <juola@suod.cs.colorado.edu> writes:

 > My understanding is that the heavy metal toxicity of Pu
 > exceeds the radioactive toxicity by several (10?) orders of
 > magnitude.  In other words, the fact that Pu is an alpha
 > emitter is irrelevant to the risk -- it's simply like lead
 > poisoning only several billion times worse.

 > Simple arithmetic yields that the amount of alpha exposure
 > from a billionth of a gram of an alpha emitter with a
 > half-life measured in thousands of years is infinitismal.

The danger stems not from the radiation effects of the alpha
exposure, which are not significant, but from the fact that
continuous long term internal exposure will eventually cause your
cells to undergo malignant transformation.  This may take several
decades, but it will kill you just as surely in the end.

With regard to this risk, internal contamination with even a
billionth of a gram of plutonium is something to worry about.

Some believe, for instance, that a good part of the risk of lung
cancer from smoking comes from inhaling alpha-emitting isotopes
of polonium and other elements that are concentrated by the
tobacco plant.  I don't know enough about this theory to agree or
disagree with it, but it has been around for a number of years.

-- 
     Mike Duvos         $    PGP 2.6 Public Key available     $
     mpd@netcom.com     $    via Finger.                      $