Re: US NRC Press Release re Thyroid Protection/Emergencies

[Eric Denison <denison.8@osu.edu>]

At 04:32 PM 1/21/98 -0600, Bob Hite wrote:
>I agree with almost everything that's written below.  I would like to
>question the last assertion, however and would be interested in some dialog
>with respect to radioIodine allergies.  My understanding is that no one is
>allergic to elemental Iodide.  The immune system does not mount a response
>to elemental ionic species.  It mounts a response to (hopefully) foreign
>macromolecules.  The perception that people are allergic to Iodine,
>including Iodine in the form of KI, was the observation that some
>individuals develop allergies to shellfish which are known to have high
>levels of Iodine.  This Iodine, however, is complexed with or actually a
>part of larger protein molecules which are what triggers the immune
>response.  If someone out there knows of research that demonstrates an
>immune response to elemental ionic species, including the Iodide in KI, I
>would be surprised.  

In all the classes that went into my major in biochem, I never saw anything
about allergies to elemental species.  There are some individuals who will
exhibit sensitivity to mildly elevated levels of various (even simple)
chemical species due to deficiencies in the systems that are responsible
for clearing excess amounts from the body.  It's possible that this is the
true nature of the iodine "allergies" to which you refer.  I'm not real
clear on the effects of elevated serum iodine levels, though.  Time for
some library work...

>                          Also, does anyone know why there is a shelf life
>associated with a salt like KI.  It has never made sense to me. I've always
>been curious if there is really any technical merit to this shelf life, or
>is it just a mechanism to ensure ongoing sales? Thanks in advance for any
>feedback.

Many times shelf life is determined less by the chemical stability of the
stuff in the container than the ability of the container to keep things
out.  How useful would the KI tabs be if they were semi-dissolved
(slurried) by encroaching water or glommed together in one huge mass.
Imagine a salt shaker in a humid kitchen with no dessicant...

Eric

Eric Denison <denison.8@osu.edu>
Radiation Safety Technician
Environmental Health & Safety
The Ohio State University