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Jerry,
I
believe that our need for sensory perception is based on its importance for
survival. I think that response to chemicals, heat, touch, and light
are important from an evolutionary perspective. As many of us know,
insects are resistant to radiation exposure. What would be the advantage
of detecting a change in radiation to an insect? At the levels of
background radiation, wouldn't radiation sensors be useful if small changes in
radiation be healthful (or harmful?). Alcohol and other
chemical occur naturally, and I do not think that we have specific
detectors for many of them, because a background levels we are not harmed by
them. However, we have strong responses to certain toxins, because they
are harmful.
I pose
the statement that at the background levels we have evolved in, radiation is
neither harmful or beneficial. Therefore, sensory organs for its detection
would not be useful.
-- John
John Jacobus, MS
Certified Health Physicist
3050 Traymore
Lane
Bowie, MD 20715-2024
E-mail: jenday1@email.msn.com
(H)
John,
I don't see
where sensory perception of a given physical or
chemical agent needs to be related in any way to its
potential harmful or beneficial effects. If that were the case, people
would not drink alcohol, or sunbath, or exercise. What feels good is not
necessarily good for you, nor is what feels bad necessarily bad for
you.
Perhaps we are
just acclimated to background radiation levels and if somehow could
be plunged into a radiation free environment would experience a sensory
deprivation of some sort.
Incidentally,
the tingling sensations I thought I had experienced in fields of ~0.1-
0.5 mSv/hr did not seem to be unpleasant. Hormesis,
maybe??? In any
case, the question posed is: Can people sense ionizing
radiation, or was I just imagining it? I really do not intend any devious implications by this
question. Just curious,that's
all....
Jerry
----- Original Message -----
Sent: Friday, May 31, 2002 10:15 AM
Subject: RE: Sensory Perception of
Radiation
Jerry,
Thank you
for passing this along.
I take it from Jim's quotation (source
unknown) that in the range of 1 mSv
to 280 mSv background levels are
inconsequential. I assume that implies
radiation as no essential
energy or having a hormetic effect quality that we
need, or else we would
have evolved sense organs for it.
I am curious as to the
statement that radiation levels of 1 mSv to 280 mSv
per year compares to a
temperature range of 50K. Where does that come from?
Obviously
temperature differences are more important to life than radiation
at
background levels.
Have a good weekend.
-- John
John
Jacobus, MS
Certified Health Physicist
3050 Traymore Lane
Bowie,
MD 20715-2024
E-mail: jenday1@email.msn.com
(H)
-----Original Message-----
From:
Jerry Cohen [mailto:jjcohen@PRODIGY.NET]
Sent: Friday, May 31, 2002 12:09
PM
To: radsafe@list.vanderbilt.edu; rad-sci-l@ans.ep.wisc.edu
Subject:
Re: Sensory Perception of Radiation
. .
.
----------------------------------------------------------------------------
"Perhaps
we humans lack a specific organ for sensing ionizing radiation
simply
because we do not need one. Our bodies' defense mechanism provides
ample
protection over the whole range of natural radiation levels-that is,
from
below 1 mSv to above 280 mSv per year.3,4 That range is much greater
than
the range of temperatures-about 50K-that humans are normally exposed
to.
Increasing the water temperature in your bath tub by only 80 K, from
a
pleasant level of 293 K to boiling point at 373 K (that is, by a factor
of
only 1.3), or decreasing it below freezing point (that is, by a factor
of
1.07), would eventually kill you.
"Because such lethal high or
low temperatures are often found in the
biosphere, the evolutionary
development of an organ that can sense heat and
cold has been essential for
survival. Organs of smell and taste have been
even more vital as defenses
against dangerously toxic or infected food. But
a lethal dose of ionizing
radiation delivered in one hour-which for an
individual human is 3000 to
5000 mSv-is a factor of 10 million higher than
the average natural
radiation dose that one would receive over the same time
period (0.00027
mSv). Compared with other noxious agents, ionizing radiation
is rather
feeble. Nature seems to have provided living organisms with an
enormous
safety margin for natural levels of ionizing radiation-and
also,
adventitiously, for man-made radiation from controlled, peacetime
sources.
"In short, conditions in which levels of ionizing radiation
could be noxious
do not normally occur in the bioúsphere, so no
radiation-sensing organ has
been needed in humans and none has
evolved."
Regards, Jim
----- Original Message -----
From:
"Jim Muckerheide" <jmuckerheide@cnts.wpi.edu>
To:
<rad-sci-l@ans.ep.wisc.edu>
Sent:
Thursday, May 30, 2002 3:28 PM
Subject: FW: [rad-sci-l] 'Voting with feet'
for/against Low vs. Hi Dose Rad!
:-)
. .
.
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