Re: [Phys-l] Isotope chemistry and physics

["Bill Nettles" <bnettles@uu.edu>]

Whether D2O should be used as a solvent for medicines, etc is a separate issue altogether from the question I had. You classified D2O as poisonous, which, in the common use of the word, it isn't. In large amounts, it has toxic effects, but so do hundreds of other things we routinely ingest, such as animal fat. That stuff stays with you a LONG time and can make your heart fail after a few years. I'm simply asking you to not be sensational with your adjectives.
 
Tritium is a whole other matter. Positron decay (very bad for your internals) to He-3, so T2O is no longer a water molecule, so you probably have free oxygen radicals produced. D2O is non-radioactive, and actually is present in the water we drink (miniscule, but there). And who knows, maybe it's actually important in the long run, much like bacteria in the GI tract. Anyone want to volunteer their future progeny to 100% P2O studies?
 
Yes, we need to be careful, but don't cast everything in a worst-case scenario. (I still eat steak and ride a motorcycle.)

> > > Bernard Cleyet <bernardcleyet@redshift.com> 3/17/2009 1:40 am >>>
Unfortunately one can't measure the bio-half life of water, but one  
can of D and T -- T especially easily.  I suspect the radio-half life  
is shorter (for T) than its bio-half life/.  A growing animal,  
especially, incorporates H into its body, probably mostly through the  
food not so much the the water it drinks.  Once in its cells its  
there until the cell is catabolized in someway, and then the cells'  
catabolites may again be incorporated in new cells.   Remember I was  
discussing the incorporation of D into cells, not the absorption of  
D2O in the intestines into the blood and the out the urine, but into  
cell matter.   True H will likely be incorporated preferentially, but  
D expelled also more slowly than H.

bc thinks the detection use of "responsible" X-raying out weighs its  
danger.  Not so the unproven use of D.

p.s. the early use of X-rays was quite irresponsible (irradiation of  
gonads while checking shoe fit, for example); will the same be the  
case w/ D use?



On 2009, Mar 16, , at 15:42, Bill Nettles wrote:

> bc--Respectfully, I think you have made an assumption about the bio- 
> halflife of D20. I doubt that it is much different from H20, and  
> any bonding effects of D vs H will be minimized in larger molecules  
> because of the scarcity of the D, even if ingesting a cup of D20.  
> So what if a sugar moelcule has C6H11D1O6? It's not going to affect  
> anything of consequence. X-rays at the denstist are much more  
> dangerous, but I wouldn't worry about them either at 2/year.

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