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RE: More on Sensory Perception of Radiation
Jim,
Thanks for the reply and information. You did hit on my concern which is
the very sensitive nature of the olfactory bulb in rodents, not to the
"smell" itself. Since only a few molecules of some agents can produce a
neural, and possibly behavior response, I was interested as to whether it
was related to the ozone directly, or some other response of the neural
receptors themselves. It is an intriguing question.
-- John
-----Original Message-----
From: james.g.barnes@att.net [mailto:james.g.barnes@att.net]
Sent: Friday, June 14, 2002 3:06 PM
To: Jacobus, John (OD/ORS)
Subject: RE: More on Sensory Perception of Radiation
Hi John,
I'm not quite sure it's not ozone related, but I don't
think it is due to a general production of ozone in the
test atmosphere (i.e., it's more complicated
than "they're just smelling it").
Several early studies showed that the irradiation was
only detected by the mice when the beam was positioned
on the head. Several other experiments have shown the
olfactory bulb is directly related to the effect
(Miyachi has demonstrated that it is the vasonomeral
regions of the bulbs that are the sensitive areas--these
are the organs that detect the sexual pheronomes, are
exquisitely sensitive, and can drive significant
behavioral changes). They had to be exposed to the head
or there was no sensitivity.
If a general ozone level being produced by radiation
were confounding the experiments, then the mice should
have been sensitive to the radiation no matter what
orientation they were in relative to the beam. Since
they were only sensitive when the head was exposed, this
argues against the possibility that the mice
were "smelling" ozone in the air.
A study done in the late 1960's demonstrated that when
ozone was introduced in the atmosphere of the test
cells, mice were NOT sensitive to radiation exposures
that they WERE sensitive to in environments without
ozone. But, when the earlier research is looked at, this
suggests that the pathway of detection is ozone being
produced in the vicinity of the olfactory apparatus;
some type of microburst of ozone production that the
olfactory bulb can detect.
Remember that Garcia demonstrated that 200 mr/sec for
0.1 sec (20 mr) was detectable by mice. While I haven't
made precise calculations, my gut reaction is that isn't
a lot of ozone being produced. Rodents have a pretty
sensitive olfaction system, so their capability
to "sense" a few molecules of radiation-produced ozone
in the vicinity very near the olfactory bulb makes
sense, especially when they can't sense it in the
present of atomopheric ozone. But I think the ozone has
to be produced in the areas near the olfactory bulbs; I
don't they're "smelling" it in the normal sense.
So I think it has been demonstrated that just a general
level of ozone in the test cell is not the basis of the
radiation sensitivity. But the question of ozone being
generated in or near the olfactory bulbs acting as the
basis of radiation detection is still open, and there is
evidence suggesting this could be the pathway.
Jim
> Jim,
> Why do you think the effect is radiation related on not ozone related?
>
> -- John
> John Jacobus, MS
> Certified Health Physicist
> 3050 Traymore Lane
> Bowie, MD 20715-2024
>
> E-mail: jenday1@email.msn.com (H)
>
> -----Original Message-----
> From: james.g.barnes@ATT.NET [mailto:james.g.barnes@ATT.NET]
> Sent: Wednesday, June 12, 2002 12:39 PM
> To: Dr Don Higson
> Cc: radsafe@list.vanderbilt.edu; rad-sci-l@ans.ep.wisc.edu
> Subject: More on Sensory Perception of Radiation
>
>
> Dear Don and all,
>
> It has been clearly demonstrated that certain animals
> have the ability to sense radiation (rats, mice,
> rabbits, etc.) at relative low doses (20 mr delivered at
> 200 mr/sec has been demonstrated as a threshold). The
> olfactory bulb has been convincingly demonstrated as the
> sensitive organ. Ozone has been demonstrated to
> interfere with the sensory process (to my knowledge, the
> specific mechanism for this interference has not been
> investigated. If I recall, it is specific to
> ozone, "fragrances" do not appear to block the sensing
> process.) If my memory serves, "avoidance" reactions
> that Dr. Myachi discussed with sand fleas have also been
> demonstrated in mice (Dr. Myachi has a very interesting
> portfolio of work in this area).
> . . .
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