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Re: Article: "Yearly full body scan ups cancer risk
I saw these comments on another list server, and
thought they were interesting enough to share. There
are really three messages. I hope it is not too
confusing.
MESSAGE ONE
--- ---------------------
Date: Thu, 2 Sep 2004 23:15:47 -0500
From: Palmer Steward <psteward@EARTHLINK.NET>
Subject: Re: Article: "Yearly full body scan ups
cancer risk
Bob Z's comments are well taken. I would add an
additional comment.
We become appropriately annoyed when we see
information being misrepresented by the press that may
exaggerate concerns of the public regarding radiation
exposure. We tend to view this as a foolish and
harmful display of ignorance on the part of the
reporter and/or his sources.
There are many radiation biologist who have spent
their professional lives studying and expanding
knowledge of radiation effects from the molecular to
the large animal level. These individuals have an
extensive fabric of knowledge upon which to examine
issues involving the possible carcinogenic effects of
small doses of radiation. The dispassionate skeptic
can appear to be a wise person. But to make fun of
the assertions of the credentialed radiation biologist
and to invade his specialty by passionately countering
his assertions with those of our own makes us appear
to be displaying our ignorance foolishly and could
possibly cause harm.
We need to be careful.
Palmer
> [Original Message]
> From: Zimmerman, Robert Edward,M.S.
<REZIMMERMAN@PARTNERS.ORG>
> Date: 9/2/2004 12:41:25 PM
> Subject: Re: Article: "Yearly full body scan ups
cancer risk
>
>I think we are getting carried away with the
radiation aspects of this subject but are missing the
most significant issue. CT scans for well people are
a misuse of the resource. The resource is limited (or
should be) and only those patients who can benefit
should have a CT scan.
> Also, the risk form treating false positives and
the societal cost to do so far outweighs any harm from
radiation risk.
>
> Lets keep this in perspective.
>
> Bob Z
>
MESSAGE TWO
--- Original Message -----
>
----------------------------------------------------------------------
>
> Date: Sat, 4 Sep 2004 00:38:34 -0500
> From: Palmer Steward <psteward@EARTHLINK.NET>
> Subject: Re: Palmer Steward's comment
>
> I agree with Carter, who is being careful to simply
state the facts. So let me recklessly invade the
territory where angels do not tread.
>
> First, by way of disclosure, I let my membership in
the Radiation Research Society lapse about 3 years ago
after failing to attend their annual meeting for about
five years. Thus I do not currently have as intimate
contact with these scientists that I used to have.
>
> A very large number of experimental systems have
been used as indicators of the carcinogenic activity
of radiation. Some of these have shown an apparent
threshold in the low-dose region, and I think most of
these scientists would expect a threshold in certain
biological scenarios. Other systems show no
indication of a threshold. A few seem to show a
supra-linear response, which I think many of the
scientists find puzzling, although possibly correct,
again, for certain situations. (As Carter can tell
you from his Penn State days when he was in the Lab.,
a careful radiation biologist learns to disbelieve his
own results until the experiment is repeated multiple
times, and sometimes, when the result comes from
another Lab., skeptics abound until still another Lab.
can support the result. Too often passions are
inflamed from results that should be considered
preliminary.)
>
> Most epidemiological studies that give clear results
are relatively high-dose situations, but some data in
the several rem range seems to be accepted. I have
the impression that there is pretty much consensus
among experimental radiation biologists regarding
low-dose issues. My impression is that most of them
agree that the linear no threshold assumption is
probably conservative for most dosing scenarios and
for most of the human population (but perhaps not
conservative for other dosing scenarios and other
human subpopulations), but in the context of all the
uncertainties from all the epidemiological and
laboratory studies, the LNT assumption is prudent
public policy. Since my contact with radiation
biologists is mostly through my old friends and
associates, my impression is hardly an in-depth
survey. Most radiation biologists seem to be busy
doing science rather than conspicuously being vocal
regarding this subject.
>
> The vocal exceptions among these scientists seem to
me to be very few, and those who have transferred
their passion for science to passion for influencing
public policy seem to be rarely selected for
membership on key NAS committees (e.g., BEIR V). The
goal of these committees is to objectively interpret
the science and consolidate current knowledge, not to
> lobby for a favorite policy or a particular set of
regulations (although the committee report is
obviously a preliminary step in the process).
>
> OK, Barry, I've tried to answer your question, so be
kind!
>
> Palmer
>
>
MESSAGE THREE
> > [Original Message]
> > From: Carter Schroy <CBS970@AOL.COM>
> > To: <MEDPHYS@LISTS.WAYNE.EDU>
> > Date: 9/3/2004 12:50:50 PM
> > Subject: Re: Palmer Steward's comment
> >
> > I think the BIER V Report is still the gold
standard in the US.
> > http://books.nap.edu/books/0309039959/html/25.html
> >
> > -- Carter Schroy (former radiobiologist)
> >
> > In a message dated 9/3/2004 1:29:20 PM Eastern
Daylight Time,
> > freedb@MSKCC.ORG writes:
> > Does the community of "credentialed radiation
biologists" have a consensus
> > opinion on the biological hazards of low-dose
ionizing radiation and, if
> it
> > does, can you please tell us what that is? Also --
does a significant minority in
> > that community dissent from the dominant opinion?
> >
=====
+++++++++++++++++++
"Everyone is ignorant, only on different subjects."
Will Rogers
-- John
John Jacobus, MS
Certified Health Physicist
e-mail: crispy_bird@yahoo.com
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