Re: [Phys-l] Isotope chemistry and physics

[Bernard Cleyet <bernardcleyet@redshift.com>]

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.