[ RadSafe ] formula for cancer risk from radiation
howard long
hflong at pacbell.net
Thu Jan 10 13:35:06 CST 2008
Bernie,
I don't understand how that equation can be correct, if there is LESS risk of cancer with supplemental
low dose, slow dose rate radiation (hormesis).
With that formula, do I understand that R (cancer risk) must always be MORE than R(0)
(no added exposure), with any additional exposure [1+ ]?
That is not true, if SOME added exposure LESSENS the risk of cancer,
hormesis, as in Cameron's NSWS analysis, Taiwan apt data of Luan, etc, etc.
Alternatively, how about R = R(0) +- S (adjusted),
changing the part that made risk with supplemental exposure always more than 1?
How about S being the supplemental exposure in Gray (with you making mathematical adjustments
to decrease risk until ~20 cGy, then increase risk) ?
Even then,
How factor in slow rate, the different effect over a year vs all at once?
How factor individual variation (like weight)?
How factor different effect on the same individual at different times (like when malnourished)?
Oversimplification misleads:
1, Global warming models omit water vapor (far more important than CO2).
2, Medical ttreatment is dictated by politicians (regardless of an individual patient's problem with compliance).
3, Nuclear power is lost with over-regulation (graphed by Ted Rockwell in his book).
Why give regulators another tool to tyrannize?
Howard Long MD MPH
----- Original Message ----
From: Bernard L. Cohen <blc+ at pitt.edu>
To: RadiatSafety <radsafe at radlab.nl>
Sent: Thursday, January 10, 2008 9:59:24 AM
Subject: [ RadSafe ] query
Can someone help me on this question -- please reply to blc at pitt.edu.
If rhe risk of cancer, R, is expressed as
R = R(0) [ 1 + k D ]
where R(0) is the risk with no exposure, D is the dose in Sv, and k is a
constant, what is the excess relative risk, ERR. I thought it would be
ERR = k. In that case, a finding that ERR = 1.0 / Sv would mean that the
risk is 2R(0) for an exposure of 1.0 Sv, 3 R(0) for an exposure
of 2.0 Sv, 4R(0) for a dose of 3.0 Sv, etc. But this is hard to
believe in a paper I am trying to understand. Any help on this would be
appreciated
--
Bernard L. Cohen
Physics Dept., University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245 Fax: (412)624-9163
e-mail: blc at pitt.edu web site: http://www.phyast.pitt.edu/~blc
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