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Jaroslav
I can't find the reference here, but I think
that the rates of enzymatic reactions was given for the hydrogen
isotopes in a book written in the seventies . I know we discussed it at
length when I worked at AECL/Chalk River. The critical number we used was ~ 30%.
That is, we thought that if the D/H ratio was below 0.3, there would be no
effect on a mammal. Concentrations above 30% would result in metabolic changes
with unknown consequences.
A glass or two of water could result in the D/H
ratio to approach 30%. I agree with the statement that it "could kill you" and
would test it on mice before drinking that it.
The major concern we had with heavy water plants
was not the D/H ratio, but the potential for hydrogen sulfide
exposure.
Regards
----- Original Message -----
Sent: Monday, September 24, 2001 5:29
AM
Subject: RE: Physical properties of
isotopes? -- H-2 question
Ruth, you wrote
:
The
only exception to this that I know of is the the differing atomic weights of
the isotopes of hydrogen (H-1, H-2, H-3) can result in slightly different
reaction rates.
Would you please, if you can, tell us whether the
above fact has any bearing on the toxicity - if any - of heavy water
?
The reason I'm asking
is that recently I was told that drinking a glass or two of high-concentration
or pure D2O would kill you, due to the
toxicity.
I'm
very dubious about this, but haven't seen anything that solidly refutes
this notion either (I thought that there wouldn't be any difference, even if
every hydrogen atom in our bodies were replaced by a deuteron.... am I
mistaken ? .....maybe somebody, somewhere, has tried raising mice on a
heavy-hydrogen diet ??).
Thanks
Jaro
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