AW: [ RadSafe ] Very Small Dosimeter

[John Jacobus]

I am having a harder time determining what is scientific news, and what are info-mercials for more funding.  I think the device might have merits for intravascular dosimetry, but not, as Rainer points out, any breakthroughs in predictin cancer risks or dosimetry at the DNA level.

Rainer.Facius at dlr.de wrote:  "This is a significant breakthrough in our ability to successfully measure different kinds of radiation and accurately predict the cancer risk of radiation exposure," said Anatoly.

"If we can model the effects of radiation on DNA level with the new radiation detectors then we are at the crest of countless possibilities," Mark concluded.

Sorry to say:

Whatever the merits of the new device as a physical dosimeter may be (the article is silent on the physics so that no one can know), it will add nothing to the understanding of (low dose) radiobiological effects - in particular to the understanding of radiogenic carcinogenesis. The better knowledge of neither the microscopic pattern of initial energy deposition in a cellular volume and not even of the initial nanoscopic pattern of DNA damage has ever reduced or will in the foreseeable future reduce the error bars on our prediction of cancer induction dose effect curves.

Neither one and a half decade of worldwide "microdosimetry" research in the late 1960s and the 1970s nor the subsequent era of "nanodosimetry" which had been funded because of the very same promises had been made by their proponents have delivered the foretold results - as the current size of the error bars testifies.

And finally, distributions of energy deposition by ionizing radiation in tissue equivalent volumes of microscopic sizes representing a cellular nucleus had been measured decades ago.

Rainer


Dr. Rainer Facius
German Aerospace Center
Institute of Aerospace Medicine
Linder Hoehe
51147 Koeln
GERMANY
Voice: +49 2203 601 3147 or 3150
FAX: +49 2203 61970

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag von Chris van den Bergen
Gesendet: Freitag, 7. März 2008 04:09
An: RADSAFE
Betreff: [ RadSafe ] Very Small Dosimeter

http://velocity.ansto.gov.au/velocity/ans0021/article1.asp
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"Part of human nature resents change, loves equilibrium, while another part welcomes novelty, loves the excitement of disequilibrium. There is no formula for the resolution of this tug-of-war, but it is obvious  that absolute surrender to either of them invites disaster."
-J. Bartlet Brebner 

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com
       
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