AW: AW: AW: AW: [ RadSafe ] Fears promoted by anti-nuclear Greens

[John Jacobus]

Rainer,
I think what you report is very typical of studies of
this nature.  Sure, you can calculate that 2049
persons in Germany might get cancer from x-ray
exposures.  But what are the limitations of this work?
 How many cancers are expected to occur every year? 
What is the uncertainty in the statistics?  (I am
always suspecious when numbers are report with such
accuracy, e.g., 2049, not 2050 or 2048?)

Some time ago, I wrote an answer to a person concerned
about his eight-year old son having a CT scan after a
head injury.  You may find my response interesting.  
>From http://hps.org/publicinformation/ate/q4173.html

. . .
With regard to the Brenner, et. al. (2001) paper you
mention, a number of points need to be made clear.
First, the study was not based on the occurrence of
cancers in real patients. His analysis is based on
studies of dose distributions in patients and
estimated cancer risks extrapolated from the doses to
the various organs irradiated.

Second, the perspective risks may be overstated based
on what is known about the natural cancer risks in
children and adults. The following is from the
conclusion:

"Although the absolute estimated risks that we have
projected are quite high, the percentage increase in
the cancer mortality rate over the natural background
rate is very low. For example, of the approximately
600,000 children less than 15 years old who are
estimated to undergo CT each year in the United
States, approximately 140,000 will ultimately die of
cancer. Thus, the estimated projected 500 CT-related
deaths represents a small (approximately 0.35%)
percentage increase over this background. This small
estimated relative risk suggests that detection of an
increased risk in an epidemiologic study would not be
easy, although a recent case-control study [35] on the
association between pediatric radiologic examination
and childhood leukemia did show a significant elevated
risk (linearly related to the number of examinations)
compared with controls in children who received two or
more diagnostic examinations (odds ratio, 1.6;
confidence interval, 1.1-2.3)."

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

> "Unfortunately, the non-scientists may not grasp the
> significance of this aspect of the arguments.
> Rather, they [only!] hear that there is a risk."
> 
> Dear John:
> 
>  
> 
> You hit the nail on its head: This exactly is the
> crux!
>                              
> *************************
> 
> Combine the LNT postulate with the outright asinine
> (ab-)use of collective dose as a prognostic tool and
> the news greedily will distribute the horror stories
> kicked off by papers like e.g.
> 
> Berrington de Gonzalez A, Darby S, Risk of cancer
> from diagnostic X-rays: estimates for the UK and 14
> other countries. The Lancet 363(2004)354-351
> 
> that in Germany 2049 persons (7587 in Japan, 5695 in
> the US) will contract cancer each year due to (to a
> large degree unwarranted) diagnostic X-ray
> exposures! They really did that!
> 
> Such 'scientific' conclusions could not be published
> if committees like BEIR would differentiate more
> strictly between data and fit paramters, between
> facts and 'model' results.
> 
> So yes, your above remark describes the heart of the
> problem. Since this appears to be unsolvable, isn't
> it reasonable to expect scientific committees to
> take into consideration the inevitable abuse of
> their statements whenever they do not most
> meticulously guard against it?
> 
> Best regards, Rainer
> 
>  
> 
> 
> ________________________________
> 
> Von: John Jacobus [mailto:crispy_bird at yahoo.com]
> Gesendet: Mi 15.03.2006 22:52
> An: Facius, Rainer; franz.schoenhofer at chello.at;
> tom.mohaupt at wright.edu; maurysis at ev1.net
> Cc: radsafe at radlab.nl
> Betreff: Re: AW: AW: AW: [ RadSafe ] Fears promoted
> by anti-nuclear Greens
> 
> 
> 
> Rainer,
> Thanks for the reply.  If you look carefully at
> reports such as BEIR VII, I do not believe that they
> say that the risks of radiation are significant. 
> One
> thing that they do say is that there are
> uncertainties
> that make a definitive statement on risks to be
> unlikely.  This is the nature of science.
> 
> Unfortunately, the non-scientists may not grasp the
> significance of this aspect of the arguments. 
> Rather,
> they hear that there is a risk.  


+++++++++++++++++++
"Those who corrupt the public mind are just as evil as those who steal from the public purse."
Adlai Stevenson

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

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