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RE: Radiation Hormesis -- or not
If it were a genetic mutation, the odds favor (immensely) a negative effect. This would translate to lower germination ratios (live plants per seed planted) and a mixture of positive and negative effects. This is not what is observed.
Dave Neil
-----Original Message-----
From: John Jacobus [mailto:crispy_bird@yahoo.com]
Sent: Friday, January 23, 2004 7:09 AM
To: Carl Speer; radsafe@list.vanderbilt.edu
Subject: RE: Radiation Hormesis -- or not
Carl,
A thought came to me. How do you know this was a
hormetic effect and not a genetic mutation? My
understanding is the a hometic effect involves the
addition of some simulus to an living organism to get
a beneficial response. You irradite mice to low doses
and you get a certain response, e.g., an increase in
the immune system. When the agent is stopped, the
hormetic effect is no longer evident after a time.
Maybe this definition for hormesis is too limiting,
but this is what I believe it is.
Seeds are not actively growing or responding
organisms. If you irradiated the growing plant, I
would agree that would be be a way of demonstrating a
hormetic effect. Did you try and grow new plants from
the seeds produced from the mature, irradiated plants?
I think that would have demonstrated the effect of
genetic mutation.
--- John Jacobus <crispy_bird@yahoo.com> wrote:
> Interesting. What were the doses?
>
> --- Carl Speer <rtrs@cox.net> wrote:
> > Karl (and others),
> >
> > We had and interesting laboratory experiment in
> > Radiation Biology when I
> > was in college where we irradiated bean seeds,
> fruit
> > flies, and onion
> > root with low, med, and high doses from a Co-60
> > source from a local
> > hospital. To show the effects of hormesis, no
> > effect, and ill effect
> > the students all received seeds from each exposed
> > group plus seeds that
> > did not get any extra dose (controls). We planted
> > the seeds in cups at
> > our home, gave all plants the same amount of water
> > and noted the
> > differences. The seeds with the low doses had
> more
> > vigorous growth,
> > smaller internodal lengths, and healthier leaves
> > than the control. The
> > higher dose plants had brown shriveled leaves,
> > stunted growth, and other
> > undesirable characteristics. We made a plot
> showing
> > that as the dose
> > initially increased we saw a net positive effect
> > (hormesis) but as the
> > dose continued to increase, a negative effect
> became
> > apparent. This
> > made a lasting impression and I have believed in
> > hormesis ever since. I
> > know people are not bean plants or fruit flies but
> > this little
> > experiment gave the hormesis theory more
> > believability than the LNT in
> > my mind.
> >
> > As for the fruit flies I don't remember the low
> dose
> > effects. What
> > stands out in my memory were the horrific
> mutations
> > in the offspring of
> > the high dose flies.
> >
> > The onion root tips were used so we could see the
> > chromosome damage in
> > the cells undergoing meiosis.
> >
> > See http://www.belleonline.com/n2v82.html
> RADIATION
> > HORMESIS: ITS
> > HISTORICAL FOUNDATIONS AS A BIOLOGICAL HYPOTHESIS
> by
> > Edward J. Calabrese
> > and Linda A. Baldwin for a good discussion on
> > Hormesis.
> >
> > Carl Speer
> > Real-Time Radiological Services, Inc.
> > 2721 Losee Rd, Suite E
> > North Las Vegas, NV 89030
> > 702.639.0066
> > www.RealtimeRad.com
> > RTRS@cox.net
> >
> >
> > -----Original Message-----
> > From: owner-radsafe@list.vanderbilt.edu
> > [mailto:owner-radsafe@list.vanderbilt.edu] On
> Behalf
> > Of
> > RuthWeiner@AOL.COM
> > Sent: Monday, January 19, 2004 7:28 AM
> > To: "Karl Ellison";
> > radsafe-digest@list.vanderbilt.edu
> > Subject: Re: Radiation Hormesis
> >
> > I have always wondered how one could distinguish
> > hormesis effects from
> > ordinary good health. An example: small amounts
> of
> > ionizing radiation
> > are supposed to stimulate bone knitting after a
> > break (I read this
> > somewhere). However, the rates of bone recovery
> > vary. Has there beenn a
> > controlled study of this phenomenon? After my
> > latest hip surgery, my
> > doctor predicted that incorporation of the bone
> > graft would take two
> > years. It took six months. I was taking a drug
> > that enhances calcium
> > metabolism and I had quite a few xrays and I get a
> > lot of exercise, so
> > was it the drug, the x-ray, the exercise, two of
> > those, or all three?
> > Are there definitive studies showing hormesis?
> >
> > I am perfectly ready to accept hormesis, but in
> the
> > current radiophobic
> > climate, I believe we are better off just claiming
> > no harm at less than
> > a particular dose. Hormesis is one of those
> > phenomena that even if it
> > is real, doesn't SOUND real.
> > --
> > Ruth F. Weiner
> > ruthweiner@aol.com
> > 505-856-5011
> > (o)505-284-8406
> >
> >
>
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>
> =====
> +++++++++++++++++++
> "I have sworn upon the altar of God, eternal
> hostility against every form of tyranny over the
> mind of man."
> Thomas Jefferson
>
> -- John
> John Jacobus, MS
> Certified Health Physicist
> e-mail: crispy_bird@yahoo.com
>
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=====
+++++++++++++++++++
"I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man."
Thomas Jefferson
-- John
John Jacobus, MS
Certified Health Physicist
e-mail: crispy_bird@yahoo.com
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