From: sbharris@ix.netcom.com(Steven B. Harris)
Subject: Re: Plutonium really the "most toxic poison known to man"?
Date: Thu, 20 Nov 1997
Newsgroups: alt.folklore.urban,alt.folklore.science,sci.physics,sci.chem,
	sci.space.policy,sci.med

In <64v3co$b152@eccws1.dearborn.ford.com> Ivan <"PITHOG<"@>ALO.COM>
writes:

>Steven B. Harris wrote:
>>
>> In <EJv2yq.B3t@midway.uchicago.edu> meron@cars3.uchicago.edu writes:
>>
>> >For a very light element, like hydrogen, the difference in mass caused
>> >by the addition of one or two neutrons is sufficient to change the
>> >physical properties appreciably, by quite a few percent, and the chemical
>> >properties by few hundred ppm.
>>
>>    But oh what a difference that makes to mammalian life!
>
>IIRC, there was an experiment done some years ago with mice and
>deuterium. The mice were fed normal food, but given pure deuterium
>instead of, "water". As I remember, the mice died of dehydration.
>The cells were unable to use the deuterium.  All because of one little
>neutron.....


Not the kind of dehydration you're probably thinking of, though.  When
body deuterium reaches about 50%, it inhibits mitosis because spindle
microtubules won't form (some hydrogen bond effect inhibiting
self-polymerization, I think).  So all eucaryotic cells are poisoned
about about these concentrations, or a little higher (bacteria can
survive full deuteration-- they just grow half as fast).  The
consequences of failure of cell division for an intact animal like a
rodent, are somewhat like those of radiation or chemo-- the bone marrow
and gut lining cells suffer.  Animals die of infection or diarrhea.

That might make a good cerebral mystery for a student text:  a person
with full control of an elderly relative deuterates them to death over
a couple of weeks to a month (which would take about 50 kg of heavy
water at $300 a kg, but nevermind).  Forensics thinks the person died
of some strange disease or poison, but can't identify one (since they
don't routinely do any tests to identify D!).   The detective only
recognizes something's amiss when the bad guy offers him ice in his
lemonade, and has forgotten to dump the ice in the icebox, which is made
from heavy water.  Detective notices the ice SINKS in his glass.
Hmmmm.

                                     Steve Harris, M.D.

From: sbharris@ix.netcom.com(Steven B. Harris)
Subject: Re: Plutonium really the "most toxic poison known to man"?
Date: Sat, 22 Nov 1997
Newsgroups: alt.folklore.urban,alt.folklore.science,sci.physics,sci.chem,
	sci.space.policy,sci.med

In <34751679.2333@sct.gu.edu.au> Rob Buckley <R.Buckley@sct.gu.edu.au>
writes:
> FAX 916-244-2924
>Based on MW, yes. D2O = 20 g/mol, H2O = 18; about 10% lighter.


D2O ice sinks in H2O--- I've done that experiment many times.

>BTW, an 80 kg person, deuterated to death, would put on about 4 kilos!
>Rob Buckley.

Yep.  I'm sure there a commandment against deuterating people to death
in deuteronomy.

From: sbharris@ix.netcom.com(Steven B. Harris)
Newsgroups: sci.physics
Subject: Re: Heavy Water - D2O
Date: 19 Feb 1998 05:36:17 GMT

In <34EBB41D.5F51C79F@aracnet.net> Dan Evens <danevens@aracnet.net>
writes:

>Uncle Al wrote:
>
>> Heavy water will display an H/D isotope effect, shutting down
>> metabolism.  Lethal dose for an average human is around 200-500 ml.
>> Small amounts are used to characterize aqueous compartment volume by
>> isotope dilution, in physiological studies.
>
>The lethal dose is news to me. Could you provide a ref ortwo for me to
>read up on this? I have a profesional interest,
>as I work in the Canadian nuclear industry. This is potentially
>very important. If we had a leak of heavy water, we maybe
>should be far more concerned (for a day or two after the
>leak) about this effect than about radioactivity.



   He doesn't know what he's talking about.  D2O isn't lethal until
about 50% of your body stores are replaced.  Since a 70 kg man contains
~40 kg of water, it follows that it's going to take at least 20 kg of
heavy water, and in practice quite a bit more, to kill you (it takes
some time to get it in--even drinking it at more than normal rates--
and during that time you pee off some).

    The mechanism of D2O toxicity is inhibition of cell division, much
like chemotherapy.  D2O inhibits polymerization of mitotic spindle
proteins.  Toxicity symptoms are much the same as any such agent, with
GI effects and bone marrow toxicity (anemia, bleeding, infection).

                              Steve Harris, M.D.

From: sbharris@ix.netcom.com(Steven B. Harris)
Newsgroups: sci.physics
Subject: Re: Heavy Water - D2O
Date: 19 Feb 1998 05:43:51 GMT

In <6cfrru$qv5$1@news.on> "Ryan Morris" <rmorris@rogers.wave.ca>
writes:

>I know that there is a heavy water molecule (D2O) for every 6000 regular
>water molecules (H2O) but if you drink or use pure heavy water just like
>you would drink regular water would you get sick or radiation poisoning
>or something?


    You'd get dizzy first (density gradients in your inner ears).  But
you wouldn't get really sick for a couple of days, even drinking the
pure stuff at 8 liters a day.  You might get some rather severe
diarrhea first, and would start to get dehydrated from that.  Later
symptoms would indeed be much like radiation poisoning, but of course
it's not radioactive.

    And BTW, it isn't that one in 6000 water molecules is a D20.
Rather, one hydrogen in 6000 is a D.  It will exist in normal water
almost certainly as a DHO molecule.

                                       Steve Harris, M.D.