Re: Radiation Hormesis

["Bernard L. Cohen" <blc+@PITT.EDU>]

T.D. Luckey has authored two books citing over a thousand experiments 

like the one described here.



Carl Speer 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.

>  

>



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