RE: D2O

[Simon "M." Jerome <smj1@npl.co.uk>]

Good morning everyone,

Point 1
As far as I know, the main hazard from D2O (which would be even worse 
with T2O) is that the labile D+ or D3O+ ions are heavier than the usual 
H+ or H3O+ ions that are found in all aqueous systems. Since many 
processes within the human body rely on transferring H+ ions around 
molecules or between molecules, the increase in mass of the ion results 
in a decrease in the speed that this occurs. Therefore such processes 
slow down. This is not a problem, say, in being able to flex your 
finger muscles, but it is a big problem in the nervous system and the 
control of metabolic rate processes. Increase the D2O concentration 
high enough and the reaction rate within the nervous system and/or the 
metabolic rate will slow down to the point where the organism becomes 
non-viable. That is to say it dies!

The more complex the organism, the more sensetive it is to increased 
levels of D2O. Needless to say, this is not an absolute rule, since 
chlorella algae actually prefers D2O to H2O and T2O to D2O. Many 
bacteria are also similarly perverse. Carp, however cannot tolerate 
>30% D2O.

The key here is reation kinetics, since doubling the mass of one of the 
components will have a far greater effect on a reation rate than 
increaing it by 1/12 (if you substitute C-13 for C-12; mice have been 
raised, and can survive with only C-13 in their organism). A minor 
effect is the position of chemical equilibrium within a system, but 
this is far overshadowed by the kinetic effect.

Point 2
Drinking D2O will have one other interesting effect. As the D2O makes 
its way around the body it gets around to the balance tubes in the 
ears. These are very sensetive to micro changes in density, mass, 
acceleration and so on. Because of this, until the subject either 
becomes wholly deuterated or voids the D2O, they become dizzy and 
disorientated and feel as if they are drunk!

I have no information on points 3 & 4

Given the cost of D2O, it would seem a fairly expensive way of killing 
someone, or, for that matter, getting drunk.

I hope that this provides a little light relief for the weekend.

Best wishes
Simon Jerome
National Physical Laboratory, UK

Email:	simon.jerome@npl.co.uk
Internet:	http://www.npl.co.uk

>
>I have a researcher doing some writing with a novel.  He has some 
specific
>questions which I am unable to answer.  Maybe one of you can address 
the
>question.  The preference would be to send the answer directly to him 
at
>masuda@webnexus.com.  
>
>1. What are the biological hazards (if any) with D2O (heavy water)?
>2. How does D2O effect the body differently from H2O?
>3. Are any of the body organs of concern with D2O?
>4. How would this be matabolized?
>
>In his novel he is considering very large amounts of D2O being given 
to a
>subject (fiction).
>
>Your input will be greatly appreciated.
>
>John Pickering
>San Jose State University
>johnjp@email.sjsu.edu
>
>The input may go directly to Jim Masuda via masuda@webnexus.com
>
>
>