AW: AW: AW: [ RadSafe ] Re: Exposed "had lower incidences of allcancers - "Environmental -

Sat Feb 10 07:44:12 CST 2007

John, 

apparently you have forgotten that it was you who did the selection. It was you who asked me how I would interpret the reduced cancer incidences and I answered to this request of yours. Regarding the leukaemia values, you again appear to have repressed or forgotten my preceding demonstration that they were utterly (even formally) insignificant. 

Regarding my inquiry as to please provide "one or two studies which you consider as presenting the most compelling evidence that low dose and dose-rate exposure to low LET ionizing radiation below say 500 mSv causes cancer" you appear to answer this by pointing to the RERF data as your sole basis for assuming that this may be so. Today you will hardly be able to find a radiobiologist studying low dose-rate effects in the laboratory at any level of biological organization above the molecular who would support the implied claim that the RERF data are relevant to chronic exposure of workers.

Nonetheless, I truly consider continued observation of the ATB survivor cohort as necessary and expedient.

Regarding the natural background radiation as one 'yardstick' to assess chronic radiation exposures we appear to agree. However, you appear to have not yet really appraised the enormous variability of this yardstick.

Kind regards, Rainer

________________________________

Von: radsafe-bounces at radlab.nl im Auftrag von John Jacobus
Gesendet: Do 08.02.2007 18:23
An: Facius, Rainer; radsafe at radlab.nl
Cc: rad-sci-l at WPI.EDU
Betreff: Re: AW: AW: [ RadSafe ] Re: Exposed "had lower incidences of allcancers - "Environmental - 

Rainer,
I guess if you only look at the data selectively, you
will find what you want.  You just choose to ignore
the leukemia values and the age based incident rates.
Maybe I am just more critical than you since you did
not see the rest of the table. 

As the RERF data demonstrated, you need to follow this
population for many years.  In 10 years, the incident
values will be different.  Of course, if you like what
you have now, why waste the money looking for more
information.

>From what I have read, it is clear that radiation
exposures do not present risk below 100 mSv acute
dose. No harmful risks have also been demonstrate for
fractionated and low dose rates 2 or 3 times
background. I think that low dose experiments are
interesting, but do not contribute much to the
epidemiological data.  Your bet (prejudice) may be
realized, but I doubt it.

--- Rainer.Facius at dlr.de wrote:

> John,
>
> regarding the "reduced cancer incidences" the
> message of table III is equally clear. Concentrating
> on the pooled incidences for men and women the data
> say:
> all cancers:       95/114.9 -> SIR95%=(0.67, 0.83,
> 1.01) : non-significant
>
> all w/o leukaemia: 88/111.6 -> SIR95%=(0.63, 0.79,
> 0.97) : formally significant
>
> all solid cancers: 82/109.5 -> SIR95%=(0.60, 0.75,
> 0.93) : formally significant
>
> In my view, for the purely statistical evaluation of
> a putative beneficial association the same criteria
> should be applied as for the appraisal of a putative
> detrimental association, i. e., these data at best
> can serve as a justification to continue such
> epidemiological investigations. Hence, I would
> hesitate to claim the above 'positive' associations
> as proof for a beneficial action of those exposures.
>
>
> However, such - by controlled, truly low dose and
> dose-rate laboratory work - well established
> phenomena like induced radiation resistance,
> adaptive response, non-monotonous dose response
> functions for several cancer related radiobiological
> endpoints at all levels of biological organization
> yield some plausibility to the assumption that
> biological mechanisms do exist which indeed might
> CAUSE the above association. My present bet
> (prejudice) is that eventually the mechanisms behind
> these laboratory observations will be sufficiently
> elucidated so that the inference of a causation of
> the statistical observations will be justified.
>
> Regarding the "consideration of all studies and not
> just one report" I would urgently invite you to
> quote the one or two studies which you consider as
> presenting the most compelling evidence that low
> dose and dose-rate exposure to low LET ionizing
> radiation below say 500 mSv causes cancer.
>
> Kind regards, Rainer
>
> Dr. Rainer Facius
> German Aerospace Center
> Institute of Aerospace Medicine
> Linder Hoehe
> 51147 Koeln
> GERMANY
> Voice: +49 2203 601 3147 or 3150
> FAX:   +49 2203 61970
>
> -----Ursprüngliche Nachricht-----
> Von: John Jacobus [mailto:crispy_bird at yahoo.com]
> Gesendet: Samstag, 20. Januar 2007 17:05
> An: Facius, Rainer; radsafe at radlab.nl
> Cc: rad-sci-l at WPI.EDU
> Betreff: Re: AW: [ RadSafe ] Re: Exposed "had lower
> incidences of all cancers - "Environmental -
>
> Rainer,
> I am aware of that interpretation about the
> significans of the of SIR values.  That being said,
> are the values for reduced cancer incidents also
> insignificant?  Or does the relevance of the numbers
> not important if you have a political view the
> radiation is good?
>
> Cherry-picking data is common.  It is used by those
> who are anti-radiation and who are looking for a
> hormetic effect.  Nevertheless, one needs to
> consider all of the studies, and not just one
> report.
>
> --- Rainer.Facius at dlr.de wrote:
>
> > John,
> >
> > if you were able to properly interpret the numbers
> given by you, you
> > would not claim that they prove an increased
> incidence, not to speak
> > of a causal relation.
> >
> > The 95% SIR confidence interval for leukaemia (all
> > types) is (0.85, 2.12, 4.37), i.e., utterly
> insignificant.
> > For malignant lymphoma it is (1.01, 3.13, 7.29),
> i.e., essentially
> > insignificant again.
> >
> > If you ask professional epidemiologists, you will
> find a consensus
> > that in order for an association to be considered
> established by such
> > studies, the confidence interval for standard
> mortality or incidence
> > ratios should exclude the value of three or at
> least two, i.e., the
> > _lower_ confidence limit should be above that
> value. Findings below
> > that value at best can serve as a rationale to
> spend money on a
> > repetition of a study.
> >
> > Kind regards, Rainer
> >
> > Dr. Rainer Facius
> > German Aerospace Center
> > Institute of Aerospace Medicine
> > Linder Hoehe
> > 51147 Koeln
> > GERMANY
> > Voice: +49 2203 601 3147 or 3150
> > FAX:   +49 2203 61970
> >
> > -----Ursprüngliche Nachricht-----
> > Von: radsafe-bounces at radlab.nl
> > [mailto:radsafe-bounces at radlab.nl] Im Auftrag von
> John Jacobus
> > Gesendet: Freitag, 12. Januar 2007 16:16
> > An: radsafe
> > Cc: Rad Science List
> > Betreff: [ RadSafe ] Re: Exposed "had lower
> incidences of all cancers
> > - "Environmental -
> >
> > Dr. Long,
> > Again, another typical example of cherry-picking
> data.
> >
> > As noted in Table III
> > Leukemia (all-types) Observed 7; Expected 3.3
> > Malignant Lymphoma   Observed 5; Expected 1.6
> >
> > If you are unable to read the article, how can one
> expect to have an
> > intelligent discussion with you?
> >
> > Why do you constantly quote the incomplete data of
> Chen, et.al. of
> > 2004?
> >
> > --- howard long <hflong at pacbell.net> wrote:
> >
> > > John Jacobus, the paper you refer to did,
> indeed,
> > mislead in its
> > > "Conclusion", comparing its tables and
> discussion.
> > >   HPs can judge for themselves:
> > >   "Correspndence: Dr W Peter Chang, Inst. of
> > Environmental Health
> > > Sciences, National Y U Med School 155, sec2
> Linong
> > St. Taipei112,
> > > Taiwan"
> > >   
> > >   Int.J. Radiat. Biol, Vol82, No.12, Dec. 2006
> pp
> > > 849-858
> > >   (The Environmental Health Sciences  review by
> > Chang et al of  cancer
> > > risks in 7,271 persons exposed to 1 to 2,363 mSv
> > gamma over 23 years),
> > >   "ABSTRACT
> > >   Conclusion [ in entirety],
> > >    The results suggest that prolonged low dose
> > radiation exposure
> > > appeared to increase risks of developing certain
> > cancers in specific
> > > subgroups  of this population in Taiwan."
> > >   
> > >    "Received 12 May 2005; revised 11 Sept. 2006;
> > accepted 18 Oct.
> > > 2006".
> > >   
> > >   The opposite impression, much cancer was
> > prevented by the radiation,
> > > is clear from its
> > >   
> > >   Table III "All cancers - Observed  95 Expected
> > > 114.9 "
> > >               "Solid cancers - Observed 82
> > Expected 109.5" and
> > >   "Discussion: - Compared to the reference
> > population, the study
> > > population had lower incidences of all cancers
> > combined, all cancers
> > > combined except leukemia and all solid cancers
> > combined (Table III)."
> > >   
> > > 
>
> +++++++++++++++++++
> "We must face the fact that the United States is
> neither
=== message truncated ===

+++++++++++++++++++
"We must face the fact that the United States is neither omnipotent or omniscient - that we are only 6 percent of the world's population; that we cannot impose our will upon the other 94 percent of mankind; that we cannot right every wrong or reverse each adversity; and therefore there cannot be an American solution to every world problem."
-- John F. Kennedy

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

____________________________________________________________________________________
Do you Yahoo!?
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com <http://new.mail.yahoo.com/> 
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the RadSafe rules. These can be found at: http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit: http://radlab.nl/radsafe/