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RE: Breast Cancer Study
Howard,
I have always been suspect of studies comparing medical patients to the
general population. Obviously, patients are not as healthy as members of
the general population. As NCRP 138 shows, there are several factors such
as age, total dose and the fact that the doses were highly fractionated.
However, it is hard to argue with the conclusion that fractionated doses are
additive.
By the way, are you referring to the Nova Scotia, with mean breast dose of
0.79 Sv, or non-Nova Scotia, with mean breast doses of 2.13 Sv studies of
Howe and McLaughlin? The percent ERR/Sv differ considerably.
-- John
John Jacobus, MS
Certified Health Physicist
3050 Traymore Lane
Bowie, MD 20715-2024
E-mail: jenday1@email.msn.com (H)
-----Original Message-----
From: hflong@postoffice.pacbell.net
[mailto:hflong@postoffice.pacbell.net]
Sent: Saturday, June 29, 2002 8:45 AM
To: Jacobus, John (OD/ORS)
Cc: Thomas Jones; radsafe@list.vanderbilt.edu
Subject: Re: Breast Cancer Study
Yes, John,
I believe that the Canadian women with breast fluorscopy had better care
than
the general population - but had been worse in nutrition, exercise etc or
would
not have gotten TB (which was declining in incidence before antibiotics).
However, my inferences about radiation effect are from Pollycove's graph
comparing mid-range with both higher and lower fluoroscopy exposures. They
were
potentially different in other respects - a reason for placebo-controlled
study.
Also you are correct, I think, in that British radiologists before 1950 were
different from those after in other ways than exposure (although Cameron
makes
other good points there and his shipyard nuclear worker study is the most
impressive human hormesis study I've seen).
. . .
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