LNT

["Kjell A. Johansen" <kajohans@powercom.net>]

It seems to me that in its most basic interpretation LNT is a test
between two sets of data to see if there is a linear relationship that
goes through zero.  The data do not have to be related or even causal in
nature.  For instance the much ballyhooed relationship between women's
hemlines and the stock market or that the market is up whenever a team
from the old NFL wins the Super Bowl.  You can test for a linear
relationship between any two data sets.  If you get a linear response it
does not mean that there is a cause and effect relationship.  It just
means that they behave in the same manner for some reason or reasons you
do not understand.  If you believe that there is a cause and effect
relationship, then you have to find one.  Also, you can come up with a
model that describes the relationship between the two sets of data.
However, if the model is not based in reality, then the model should
fail in its prediction of outcomes of future events.

Now, I may be wrong on this, but if Bernie Cohen tests two sets of data
for a simple linear relationship that goes through zero and does not
find one, then the data must not support a no threshold hypothesis even
though the two variables maybe linearly related at some other points.
He could be testing hem lines and the stock market. Or, in this case, he
is testing radon concentrations and lung cancer.  If we did not know
that there is a link between radiation and .  cancer, then we would that
there is no linear relationship that goes through zero.  However, we
have observed that there is a link.  So why does it not go through
zero?  If I understand him correctly, Bernie is asking for some testable
hypothesis for why the data do not go through zero.  If the linear
hypothesis is correct, it should successfully predict the number of lung
cancers in the high radon areas of the world. Unless I have missed it, I
do not recall seeing any such data from the studies in India and China.
Therefore, there must be some point at which radiation damage to the
system overwhelms the body's ability to repair/delete/cancel the damage.
At that point the there may be a positive, linear relationship but it
would appear that below that point none exists.

Kjell Johansen
Milwaukee
kajohans@powercom.net



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