LNT Mechanisms

[epirad@mchsi.com]

Interesting recent paper on the LNT issue.  



J Radiol Prot 2003 Mar;23(1):53-77 



A contribution to the linear no-threshold discussion.



Chadwick KH, Leenhouts HP, Brugmans MJ.



Department of Biological Sciences, Lancaster University, Lancaster LA1 4YQ, UK. 

kennethhchadwick@aol.com



The paper approaches the linear no-threshold (LNT) hypothesis, currently used 

as the basis for recommendations in radiological protection, from the point of 

view of the radiation mechanism. All considerations of the validity of the LNT 

hypothesis based on experiment or epidemiology are dismissed because of the 

impossibility of deriving statistically significant data at very low doses. 

Instead, the LNT hypothesis is assessed from a consideration of the mechanism 

of radiation action. The DNA double-strand break is proposed to be the crucial 

radiation-induced molecular lesion. A trace is made using a series of 

correlations that link the DNA double-strand break to effects at the cellular 

level and these cellular effects are linked to the induction of cancer. 

Multistep modelling of carcinogenesis is used to take the link through to a 

consideration of radiation risk. It is concluded that, from the point of view 

of radiation mechanism, at very low doses the LNT hypothesis of radiation 

action is valid, that is, the risk function has a positive slope from zero dose.

> Milton,I think if you review the mailings, you will see that Dr. Cohen has 

> always been treated with respect.  Many disagree with his evaluation of the 

> data, and have tried repetatively to point out problems that they think exists.  

> You should know that some individuals on this list are not health physicists, 

> but epidemiologist whose job is to analyze data and evaluate results.  Dr. Cohen 

> has been intransigent in his defense, which is his right.  I believe Dr. Cohen 

> is willing to have the NCRP look into his data, which will hopefully provide 

> some insight into the appropriateness of his data and analysis.  (Of course, 

> there are some on this list who will never accept a result that contradicts 

> their believes.)  Discourse is important in science to develop theroies and 

> advance research, and should be fostered.   I believe all of the radiation 

> issues are routinely discussed on this list, so none are being ignored.

> 

> "Chilton, Milton W." <chilton@NV.DOE.GOV> wrote:Bernie, I believe your move is a 

> wise one and I certainly believe you have

> every right to make such a request. You have certainly taken a valid

> scientific approach in inviting open discussion and critique. Unfortunately

> our current society seems to find it easier to throw dispersions and

> personal attacks against the scientist than it is to maintain a professional

> and objective dialogue. I personally am getting tired of the continuing flap

> and like others may finally choose to unsubscribe myself because of the

> endless attacks on individuals. 

> 

> With all of the challenges we have currently in the rad arena you would

> think that members of the list could find more appropriate and beneficial

> uses for their time. . . .

> 

> -- John

> John Jacobus, MS

> Certified Health Physicist

> e-mail:  crispy_bird@yahoo.com

> 

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