Re: Nonlinear alphas

[Bernard L Cohen <blc+@pitt.edu>]

	If the principal mechanism for cell killing is passage of a 
single alpha particle, the probability for a cell to be killed must be 
linearly proportional to dose. If a single alpha particle has a 
probability of not killing a cell = p and a probability of causing a cancer 
if the cell is not killed =q, the probability of it causing a cancer is
p x q. Then the probability of N alpha particles causing a cancer is
N x p x q, which is proportional to N, and therefore linearly 
proportional to dose. 

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Thu, 1 Aug 1996, David Scherer wrote:

> OK, it wasn't my last try.  Melissa is back in town and she tells me that
> the problem is using the word *From* as the first word in a paragraph.  She
> says *To* will give similar results.  Thought you all might like to know.
> 
> Dave
> 
> >B. Cohen pointed out that LNT for radon exposure is based on linear
> extrapolation from miner studies, regardless whether the biological insult
> is cell killing or something else.  I was simply suggesting one possible
> mechanism that could result in a difference from low LET radiation and
> result in different dose-response curves for the two types of radiation.  If
> there is substantial cell killing with alpha radiation at low doses, but not
> with low LET radiation at low doses, there could be two competing outcomes
> for alpha radiation, one carcinogenic and one not.  (As I said before, dead
> cells do not become cancer.)  The combined response might be non-linear.  If
> there is litle or no cell killing with low LET, cancer induction might be
> linear.
> >Dave Scherer
> >scherer@uiuc.edu
> >
>