LNT - a semantic comment

["Bjorn Cedervall" <bcradsafers@HOTMAIL.COM>]

I occasionally see the controversies around LNT but essentially stopped 

commenting here a few years ago. There is one aspect however that I believe 

needs more attention - what the concept means. As I see it:



LNT is not a theory

LNT is not a hypotehesis

LNT is a tool



LNT is about an extrapolation down into a region where we in the 

mathematical limit can have no knowledge about what the mechanisms are 

doing.



A theory should, in a solid way, explain what is going on in terms of 

mechanisms. Molecular biology is too complex to allow for all that in the 

detailed sense. A _hypothesis_ is usually put forward to see if a theory can 

be strenghtened (like "lets see if apoptosis will modify the theory in the 

low dose region"). With this interpretation LNT is not a hypothesis either.



Instead, LNT is more of an administrative tool, the linear extrapolation. It 

can be used for statements like "this alternative is probably (//I emphasize 

this word//) better than that".



The misuse comes from multiplying small doses with large populations over 

many years. The anti-nuclear/radiation activists will continue this 

multiplication gymnastics regardless of what we think about it. The lack of 

relevance - besides the _actual_ shape of the cancer vs. dose function 

(whatever it is like) when projected into the future may partly be due to 

pseudotruncation of genomes less fit for survival (several "bad" genes may 

disappear with the death of one individual).

This means that a focus on time integrals (projection into the future) 

describing genetic damage rather than doses for risk analysis. The outcome 

of such analysis may, for some folks, not be politically correct but perhaps 

more relevant.



Please don't hesitate to comment, add or subtract to this.



My personal thoughts only,



Björn Cedervall     bcradsafers@hotmail.com

http://www.geocities.com/bjorn_cedervall/





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