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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
. . .
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"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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