AW: AW: [ RadSafe ] Excess relative risk

[Rainer.Facius at dlr.de]

John:

The selection below of two out of nine desiderata by one of the nestors
of epidemiology, Sir Austin Bradford Hill, may provide for another
explanation for our controversy.

1) You appear to rely on those experts which cherry-pick (to use one of
your favorites) those studies which show positive associations -
although often only for gratuitous choices of one-sided significance
tests at significance levels of only 90% !!! I assume your position does
not prevent you from realizing that well published human studies exist
which display negative associations. Some of them have repeatedly
presented to you (apart from Shipyards and domestic radon). Given that
to my knowledge the number showing negative associations equals or even
surpasses those with positive association, the very very least you are
entitled to claim is that an essential proviso is violated which would
allow you to "cry for causation", i.e., consistency. By the way, the
inconsistency comprises also the "volatility" of organs/sites for which
'significant' positive associations between low dose and dose rate
exposures to sparsely ionizing radiation and cancer risk.

2) You appear to rely on those experts which still hold that knowledge
of the statistics for the induction of initial ionization events in some
10^-15 s in a biologically important molecule suffice to predict
conclusively the induction of cancers in an organ 10^8 s after such an
event. It was this primitive target theory which guided experts more
than half a century ago to formulate the LNT postulate, although already
then the original founders of target theory had long ago pointed out its
limitation to 'inert' systems which are incapable to mount counteractive
responses. Half a century after Elkind and Sutton (1959) and a quarter
century after Olivieri, Bodycote and Wolff (1984) and in view of the
subsequent laboratory research such an assumption is implausible to the
utmost in view of "the biological knowledge of the day". Hence another
proviso to "cry for causation" is violated. 

Though I would not claim that hormesis has been conclusively established
for human cancer risks after low dose and dose rate exposures,
plausibility and consistency (with respect to laboratory work)
definitely favour it as compared to the LNT postulate. 

Given that the scientific case for causation is non existent in the
relevant exposure regime, I think your occasional characterization of
the LNT postulate as 'political' is warranted - as is the question "cui
bono?"

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
 
Hill A B, 
The Environment and Disease: Association or Causation.
Proc Royal Soc Med 58(1965)295-300 (ISSN 0035-9157)

"Here then are nine different viewpoints from all of which we should
study association before we cry causation. 

...

(2) Consistency: Next on my list of features to be specially considered
I would place the consistency of the observed association. Has it been
repeatedly observed by different persons, in different places,
circumstances and times?

...

(6) Plausibility: It will be helpful if the causation we suspect is
biologically plausible. But this is a feature I am convinced we cannot
demand. What is biologically plausible depends upon the biological
knowledge of the day."


________________________________

Von: John Jacobus [mailto:crispy_bird at yahoo.com] 
Gesendet: Dienstag, 12. Februar 2008 04:34
An: Facius, Rainer; hflong at pacbell.net; ograabe at ucdavis.edu;
radsafe at radlab.nl
Betreff: Re: AW: [ RadSafe ] Excess relative risk


One of the purposes of a skeptic is not so much to challenge as to
present what is unknown.  
 
I have been accussed of being silent.  I am not an epidemiologist, so I
have to relie on those who are recognized experts. (If you choose to
ignore the conclusion of experts, that is your choice.)   The consensus
has been that there are no demonstracted effects below 100 mSv.  Neither
harmful or beneficial.  All studies are individual pieces of a puzzle.
To date, the well-known epidemiologists have reached the conclusion
stated above.  Individual studies may support your position or mine, but
the concensus has always remained the same.   
 
Your uncited comments below are interesting, but how do they fit in the
overall study of radiation effects?  I have seen some studies that do
show negative slopes.  We can all cherry pick the data that supports our
positions, but what do the experts say?