[ RadSafe ] Annual dose from Nature/Background/Man-made sources
Kai Kaletsch
eic at shaw.ca
Wed Aug 1 13:51:47 CDT 2007
Rainer,
there are 2 ways to have high radon levels in a building:
1) let lots of radon into the building (build on fractured soil, build in a
high radium area...). And
2) Keep the radon that you have inside the building (keep doors and windows
closed).
The second mechanism presents some obvious problems for case control studies
and I'm not sure they have been addressed.
For example: If your house has poor ventilation, you also increase the level
of other indoor air pollutants, as well as radon. So, if you find an
association between radon levels and cancer, it could be due to these other
pollutants.
But, even if we take the case control studies at face value, they are easy
to reconcile with Cohen's results, if we say dose is not the only relevant
measure.
I'd like to see some animal studies looking at the effects of timing and
rate of radon exposure.
Regards,
Kai
----- Original Message -----
From: <Rainer.Facius at dlr.de>
To: <eic at shaw.ca>; <radsafe at radlab.nl>
Sent: Wednesday, August 01, 2007 11:37 AM
Subject: AW: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
Kai,
thank you for your clarification.
I concur with your statements and I tried to select my wording so that it
did not imply beneficial effects hiding behind these Cohen data (although
they very well might). On the other hand, they demonstrate that there is no
rational reason either to suspect detrimental effects, and even worse, to
spend money to reduce such exposure levels. Regarding the findings from case
control studies, I suspect that they often suffer from some kind of
'selection' bias - although I know the textbook assertions that (if
properly! done) cohort and case control studies should yield the same
results. So far I have received no comprehensible answers to my several
questions to experts why very often case control studies find 'positive'
associations with some putative toxin where cohort studies don't.
Regarding the importance of dose rate studies, my feeling is that we just
have scratched the surface of the phenomena and may have yet to learn how to
pose the proper - experimentally determinable - questions. This includes of
cause the proper allowing for the varying physiological state of the
'target'.
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: Kai Kaletsch [mailto:eic at shaw.ca]
Gesendet: Mittwoch, 1. August 2007 18:19
An: Facius, Rainer; radsafe at radlab.nl
Betreff: Re: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
Hi Rainer,
I agree that all attempts at using confounders to explain away the health
benefits of living in a high radon area have failed. However, this does NOT
imply that living in a high radon house has health benefits.
It could be that visiting your neighbor once a month, who has very high
radon levels, provides the protective effect to you. Your neighbor on the
other hand, who is exposed 24/7, would not get any benefit (or maybe even a
slight increase in cancer risk). Overall, the area would still show a net
reduction in cancers. [...and it would also produce the results that the
case control studies claim to show.]
Once you accept that LNT is not an accurate description of radiation
effects, you also have to accept that dose is not a relevant quantity. You
showed a graph a while ago relating health effects to dose rate, rather than
dose. I think this is on the right track.
It may also be that the timing of the exposure is relevant. I think I'm
supposed to exercise 3 times a week for about an hour each. If someone were
to exercise 7 days a week 16 hours each, they would probably do some damage.
Regards,
Kai
Kai Kaletsch
Environmental Instruments Canada Inc.
----- Original Message -----
From: <Rainer.Facius at dlr.de>
To: <Peter.Vernig at va.gov>; <idias at interchange.ubc.ca>;
<jdaitken at sugar-land.oilfield.slb.com>; <Mike.Brennan at DOH.WA.GOV>;
<radsafe at radlab.nl>
Sent: Wednesday, August 01, 2007 1:22 AM
Subject: AW: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
"... a few of us, unfortunately have a very high [radon] exposure if we live
in a problem house ..."
Peter:
Why do you call the 'few of us' unfortunate if indeed the fact of being
exposed to higher levels of domestic radon has incontrovertibly been shown
to be associated with significantly reduced lung cancer mortality - in line
with most other studies, which have investigated the association of low dose
and dose rate exposure to ionizing radiation with lung cancer? Proposed
explanations of the radon findings by means of confounders abound but I have
seen none published which was amenable to a quantitative analysis and which
could be upheld in the light of a subsequent quantitative re-analysis by
Bernard Cohen.
Regards, Rainer
BTW: Notwithstanding my many recurrent failures, I endeavour to adhere to
your admonition transmitted from Paul of Tarsus :-)
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 Vernig, Peter G.
Gesendet: Mittwoch, 1. August 2007 00:14
An: John R Johnson; Doug Aitken; Brennan, Mike (DOH); radsafe at radlab.nl
Betreff: RE: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
I agree too, one can use NCRP Report 94 which is natural background and has
a rounded total of 300 mrem/y.
But it includes Radon which I also don't like because presumably most of us
have a pretty small exposure if we live in houses that do not have a
significant radon exposure and a few of us, unfortunately have a very high
exposure if we live in a problem house and that all is rounded to 200 mrem.
Although Radon in natural.
Any opinions in this e-mail are solely those of the author, and are not
represented as those of the VA Eastern Colorado HCS, the Dept. of Veterans
Affairs, or the US Government.
Peter G. Vernig, Radiation Safety Officer, MS-115, VA Eastern Colorado
Health Care System, 1055 Clermont St. Denver, CO 80220, peter.vernig at va.gov,
Phone= 303.399.8020 x2447; Fax = 303.393.5026, alternate fax, 303.393.5248
"...whatever is true, whatever is noble, whatever is lovely, whatever is
admirable, if anything is found to be excellent or praiseworthy, let your
mind dwell on these things."
Paul of Tarsus
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of John R Johnson
Sent: Tuesday, July 31, 2007 3:51 PM
To: Doug Aitken; Brennan, Mike (DOH); radsafe at radlab.nl
Subject: Re: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
Doug an Mike
I agree that medical exposures are not background. Isn't that why UNSCEAR
(http://www.unscear.org/unscear/en/publications/1988.html) has two annexes?
John
***************
John R Johnson, PhD
CEO, IDIAS, Inc.
Vancouver, B. C.
Canada
(604) 222-9840
idias at interchange.ubc.ca
----- Original Message -----
From: "Doug Aitken" <jdaitken at sugar-land.oilfield.slb.com>
To: "Brennan, Mike (DOH)" <Mike.Brennan at DOH.WA.GOV>; <radsafe at radlab.nl>
Sent: Tuesday, July 31, 2007 1:58 PM
Subject: RE: [ RadSafe ] Annual dose from Nature/Background/Man-made sources
> At 03:37 PM 7/31/2007, Brennan, Mike (DOH) wrote:
>>While I was never a fan of the old pie chart, I am less a fan of the
new
>>one and the message sent by changing it.
>>
>>I don't believe that medical exposure should be included in chart
>>background or average exposure. No own receives an "average" medical
>>exposure: they either receive a medical exposure or they do not. If
you
>>have 100 people and 10 of them receive medical exposures of 1,000 mR
>>each, their exposure in no way affects the other 90 people. If those
>>ten get 10,000 mR each, it STILL doesn't effect the other. Changing
the
>>number of people in the population changes the average, but doesn't
>>change the effect on the people receiving exposure, or those not.
>
> I have to agree with this!
>
> There is a great difference between (1) what you can avoid
(occupational
> doses for radiation workers, medical doses for everyone - which should
all
> be judged/justified on a risk-benefit basis) and (2) those you cannot
> avoid (natural, fallout, etc).
>
> Of course, you "can" minimize the second category by moving your place
of
> residence..... (if you see any benefit in this <G>)
>
> Regards
> Doug
>
>
>
> Doug Aitken Cell Phone 713 562-8585
> QHSE Advisor
> D&M Operations Support
> Schlumberger Technology Corporation
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