[ RadSafe ] RE: Radon and Lung Cancer

[Wesley]

Dear Otto,

 

Thank you for your critique of my paper on lung cancer, radon and altitude. 

 

Let me address your comment on oxygen tension in the body and physiological
adaptation to altitude.  I gave this a lot of thought, and the key point is
that the cells in the pulmonary system that are in contact with the air are
in contact with air at the prevailing pressure and therefore oxygen tension.
All other cells in the body make use of some adaptation to get their needed
oxygen. It is this reason that I would expect lung and mouth cancer to be
effected by altitude, but not other cancers. Unfortunately for the
epidemiologist, the same tissues (lung, mouth) directly in contact with the
air are also in contact with cigarette smoke. Let me quote from my paper:

 

Cells in the lung are in direct contact with the inspired air. Atmospheric
air has a fixed oxygen fraction, i.e., 20.95% by volume. At higher
elevations above sea level, the absolute concentration of oxygen is lower,
and the individual cells of the lung are in contact with fewer oxygen
molecules. Unlike most cells of the body, the oxygen environment of cells of
the lung in contact with the air is not under the body's physiological
control. Persons who live at higher elevations adapt to the lower
atmospheric oxygen concentration by physiological changes such as increased
breathing rate, increased tidal volume, pulmonary hypertension, changes in
blood chemistry, increased numbers of red blood cells, etc. Thus, at lower
elevations above sea level, the cells of the lung experience higher absolute
oxygen concentrations but other cells and organs have oxygen levels which
are under the body's physiological control and tend to be constant with
elevation.

 

In summary, there is a plausible biological basis for altitude (oxygen
tension) effecting lung and mouth cancer, but not other cancers. 

 

Best regards,

Wes

Wesley R. Van Pelt, PhD, CIH, CHP

 <http://mysite.verizon.net/wesvanpelt/index.html> Wesley R. Van Pelt
Associates, Inc.

 

  _____  

From: Otto Raabe [mailto:ograabe at ucdavis.edu] 
Sent: Tuesday, February 13, 2007 8:29 PM
To: Wesley; 'RADSAFE'
Cc: 'Bernard L. Cohen'
Subject: Re: Radon and Lung Cancer

 

At 08:36 AM 2/13/2007, Wesley wrote:



I would like to remind you of my paper in Health Physics (October 2003):
EPIDEMIOLOGICAL ASSOCIATIONS AMONG LUNG CANCER, RADON EXPOSURE AND ELEVATION
ABOVE SEA LEVEL - A REASSESSMENT OF COHEN'S COUNTY LEVEL RADON STUDY

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Dear Wes, 

I believe that the cellular oxygen tension is about the same no matter what
altitude you reside. If you grow up at high altitude you will develop bigger
more efficient lungs, If you move to a higher altitude you will have an
increase in red-blood cell concentration. In any case, at the cellular level
there will be about the same biologically balanced oxygen tension. No
radiation effects are expected.

There is a general correlation between higher radon and altitude.  That is
somewhat of a coincidence.  There is also an inverse correlation between
latitude and oxygen concentration. A mathematical regression will treat
decreased oxygen and increased radon as somewhat mathematically correlated
even though they are not related, but decreased oxygen is not necessarily a
causative factor in this relationship. It is just a partial surrogate for
increased radon.

When Prof. Cohen evaluated just the former Confederate (southern) States
where there are few high altitude Counties, he got the same inverse
relationship as for the whole nation. Therefore, I concluded altitude is not
a directly important factor in the inverse radon -lung cancer relationship.

Otto
**********************************************
Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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