Re: Ancient radiation levels were higher than today's levels

[Chris Davey <chris.davey@cancerboard.ab.ca>]

> Bernard L Cohen wrote:
> >         According to a forthcoming paper by Pollycove and Feinendagen,
> > chemical and thermal effects cause 150,000 single strand breaks and 200
> > double strand breaks per cell per day. By comparison, 10 rem of radiation
> > causes 200 single strand breaks and 4 double strand breaks per cell. If
> > double strand breaks are the source of cancer initiation, 10 rem of
> > radiation per year causes 4 double strand breaks per cell per year which
> > increases the number of cancer initiations by 4/200 = 2%. However,
> > according to linear-no threshold theory, 10 rem of radiation per year
> > increases one's cancer risk by 150% -- a very large discrepancy..
> (snip)

Actually, 200 double strand breaks per day is 73000 per year, so 4
more is only 0.005% more.  Hope I'm not missing something here...

Regards,

Chris Davey
--
RSO / LSO Cross Cancer Institute 11560 University Avenue
Edmonton Alberta Canada T6G 1Z2
(780) 432-8616 fax 432-8615
email: cdavey@med.phys.ualberta.ca     chris.davey@cancerboard.ab.ca
pager number 005, just call (780) 432-8771 and ask for that pager

> (Quote continued)
> >         I consider this to be one proof (among many others) that cancer
> > initiation by DNA damage is not the controlling factor in radiation
> > induced cancer, which destroys the logical basis for linear-no threshold
> > theory.
> >
> > >
> > Bernard L. Cohen
> (end)
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