[ RadSafe ] Re: LNT/threshold/hormesis - what do HPs really

[John Jacobus]

I think it is also fair to note that this is only
based on one study.  However, if one looks at all the
types of studies, e.g., thyroid cancers, lung cancers,
incident rates, etc., what model fits all of the
various types to some degree of reliability?  It is
certainly possible that the LNT does not fit the
results for one type of cancer.  How well does it do
for ALL cancers collectively?

Again, the BEIR VII says that leukemia cancers are
better fitted to a linear-quadratic.  

--- "Muckerheide, James" <jimm at WPI.EDU> wrote:

> Andy, All,
> 
> Abel Gonzalez (and other LNT supporters) cleverly
> misrepresent the fact that
> it would take a large number of cases to disprove
> the LNT ONLY if you assume
> the LNT is true!  
> 
> See the following plot to indicate results of the
> presumed LNT (dotted line)
> vs. the actual data at/below about 15 cGy (using in
> the larger 'Other
> Provinces' data):
> 
>
http://cnts.wpi.edu/RSH/Docs/Pollycove/Pollycove2000_Symposium/Image29.gif
> 
> 
> Look at the 1 cGy (1 rem) "limit" which indicates
> that it would indeed take
> millions of people to demonstrate a difference
> between the LNT line AND THE
> ZERO-EFFECTS LINE.  Here, the 15 cGy group is about
> 200 women (I'd have to
> check the data table).
> 
> Note:  I will even accept the LNT below 1 cGy - if
> the LNT interpolation of a
> straight line starts from the actual data at 15
> cGy!!  :-)
> 
> Note further:  This study was claimed to be the most
> significant data in the
> BEIR V report!  It is one of the 7 listed as the
> basis for the BEIR V
> modeling!?
> 
> And:  The LNT mandate caused the authors to present
> this as "the LNT is the
> better fit" (vs. the LQ fit) while ignoring their
> own data.  The original
> NEJM paper presented this data in a table, but the
> data (without the fitted
> line) was plotted and presented by Ted Webster as
> the 1992 NCRP meeting
> annual Lauriston Taylor lecture!  
> 
> The study was quickly updated (1996) BUT with all of
> the data in the low dose
> groups lumped into one point from 1 to 49 cGy to
> obfuscate these results.  In
> questioning, on at least two occasions, the author
> said "They like straight
> lines." 
> 
> There is additional discussion at Figure 6 in the
> paper:
>
http://cnts.wpi.edu/RSH/Docs/Pollycove2000_Symp_on_Med_Ben.htm
> 
> 
> You can get the full ref to Miller 89 and PubMed
> abstract at: 
> http://tinyurl.com/awuum 
> 
> Regards, Jim Muckerheide
> =========================
> 
> 
> > -----Original Message-----
> > From: radsafe-bounces at radlab.nl
> [mailto:radsafe-bounces at radlab.nl] On
> > Behalf Of A Karam
> > Sent: Wednesday, July 20, 2005 12:57 PM
> > To: Rainer.Facius at dlr.de; radsafe at radlab.nl
> > Subject: RE: [ RadSafe ] Re:
> LNT/threshold/hormesis - what do HPs really
> > 
> > I have received several comments to this effect,
> to the point where it
> > makes sense to post to the entire list.
> > 
> > In his 2004 Sievert Lecture, Abel Gonzalez
> presented a very interesting
> > figure showing the number of research subjects
> needed to prove, or
> > disprove LNT as a function of the dose each person
> received.  Using
> > current epidemiological and statistical tools, he
> made a fairly
> > convincing case that to show the presence or
> absence of effects at low
> > levels of exposure - less than a rem - takes so
> many subjects that such
> > studies are virtually impossible to perform or to
> fund.
> > 
> > So; epidemiological science seems unable to prove
> or disprove any
> > particular model of radiation dose-response at low
> levels of exposure.
> > Radiation biology seems able to point us towards
> an answer, but seems to
> > somehow leave many people unsatisfied that studies
> of individual cells
> > are applicable to entire organisms.  So, at
> present, I get the
> > impression that no scientific community will be
> able to prove (or
> > disprove) its case to the radiation safety and
> radiation biology
> > community as a whole. In addition, we must admit
> that, even in the most
> > limiting case (LNT), the risks from radiation do
> not warrant the public
> > health precautions that are taken and funded - the
> radiation safety
> > agenda (on a national and international scale) is
> driven by politics and
> > opinion rather than science.
> > 
> > That being the case, I'm simply interested in
> knowing where the
> > professional, well-informed opinions fall out.  We
> hear a lot of heated
> > debate, but since the great majority of Radsafe
> members sit quietly at
> > their computers, I have no idea how the radiation
> safety community as a
> > whole feels on the matter.  And, let's face it,
> you're not going to get
> > a true feeling for that in a public forum because
> so many feel
> > constrained by peer pressure, employer
> requirements, not wanting to look
> > like an idiot, and so forth.
> > 
> > Best regards,
> > 
> > Andy
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+++++++++++++++++++
"Every now and then a man's mind is stretched by a new idea and never shrinks back to its original proportion." -- Oliver Wendell Holmes, Jr.

-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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