RE: Uranium used in dental crowns

[John Jacobus <crispy_bird@YAHOO.COM>]

I believe that Franz was saying that the cerium in

dentures would be from natural sources and not

radioactive.  The nine isotopes I have have on one

list are

Ce-134, 3016 day half life

Ce-136, Stable

Ce-138, Stable

Ce-139, 13736 day half life

Ce-140, Stable

Ce-141, 32.5 day half life

Ce-142, Stable

Ce-143, 1.38 day half life

Ce-144, 284.6 day half life



Of these, five are radioisotopes as they undergo

nuclear transmutation.



--- "Dukelow, James S Jr" <jim.dukelow@PNL.GOV> wrote:

> Franz Schoenhofer wrote:

> -----Original Message-----

> From: Franz Schoenhofer

> [mailto:franz.schoenhofer@CHELLO.AT]

> Sent: Monday, August 18, 2003 6:34 PM

> To: Peter Diehl; radsafe@list.vanderbilt.edu; Chuck

> Cooper

> Subject: AW: Uranium used in dental crowns

> 

> 

>      <snip> 

>  

>  ------------------------------------------------

> 

> "Cerium" has not a single naturally occurring

> radioactive element to my knowledge. I doubt that

> this nonsense is distributed via WISE, hopefully

> not, because I regard their website as an

> astonishing neutral and reliable source of

> information (PD????). The fluorescence of uranium

> compounds has nothing to do with the radioactive

> properties of uranium!!! That many compounds of rare

> earth elements show fluorescence, though they are

> not radioactive is more than well known - otherwise

> we would not have color TV, a lot of important

> bioanalytical tests would not be possible, just to

> name a few applications of rare earth compounds. Why

> is everything strange attributed to radioactivity?

> 

> Best regards,

> 

> Franz 

> 

>  ================

>  

> I seem to remember Ce-134, and indeed, my copy of

> Nuclides and Isotopes, 14th Ed., has Ce-134, Ce-137,

> Ce-139, Ce-141,  Ce-143, and Ce-144 as naturally

> occurring radioisotopes.

>  

. . .



=====

-- John

John Jacobus, MS

Certified Health Physicist

e-mail:  crispy_bird@yahoo.com



__________________________________

Do you Yahoo!?

Yahoo! SiteBuilder - Free, easy-to-use web site design software

http://sitebuilder.yahoo.com

************************************************************************

You are currently subscribed to the Radsafe mailing list. To unsubscribe,

send an e-mail to Majordomo@list.vanderbilt.edu  Put the text "unsubscribe

radsafe" (no quote marks) in the body of the e-mail, with no subject line.

You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/