Re: Radon and lung cancer

[Bernard L Cohen <blc+@pitt.edu>]

On Tue, 3 Mar 1998, David Scherer wrote:

> Dr. Cohen said, in part:
> 
> >        -It is a basic principle of "The Scientific Method" that if data
> >exist that cannot be plausibly explained by the theory, the theory fails.
> >If you don't agree with this statement, please say so, and I will expound
> >further.
> 
> The Scientific Method does not require that every result be embraced, only
> those results that have been replicated and confirmed with several
> techniques.  There are lots of anomalous results in science that are
> neither refuted nor embraced.

	--They don't have to be refuted; they only have to be explainable
in some way that is not implausible. In most cases, this would be
experimental error.
	In our case, the same experimental errors would have to afflict
our data, the EPA data, and the data collected by various state agencies.
Moreover, the experimental errors in counties would have to have an
extremely strong negative correlation with radon levels--i.e.counties with
high measured radon levels would have to actually have low radon levels,
and vice versa, and this would have to apply in each section of the
country, etc.  

>I will give one example from physics, since
> Dr. Cohen has worked in that arena with some distinction.
> 
> In the 70's Bill Fairbank (Stanford) detected fractional charges on small
> superconducting niobium spheres.  To my knowledge, no one has ever
> explained his results, yet physicists universally hold to charge
> quantization and absolute confinement of quarks.  I would ask Dr. Cohen
> whether he disagrees with this statement and whether The Scientific Method
> has been abridged.

	--Fairbank's observation was a single event (the plurals in the
above are not correct) recorded by an automatic recorder with no one
present. It was taken very seriously by the scientific community with
great efforts to reproduce another such event ending in failure. There was
a very large  body of other evidence that a single quark is not
observable. Thus the observation was charged to experimental error.
	In my study, the result is duplicated with our data, with EPA
data, and with data collected by state agencies. In the compilation, it is
duplicated for each region of the country individually,(and for United
Kingdom). Actually, our study of 1600 counties can be considered as 10
studies of 160 counties each, with the choice of counties in each of these
made randomly or by any of hundreds of specifications (e.g. only the most
urban counties, only the most rural counties, only the richest counties,
etc, etc.) Always the same result is obtained.
	Another major difference is that there is no other evidence
supporting linear-no threshold theory in the dose region of my study. In
fact there is a substantial body of other evidence suggesting that the
theory fails, as was found in my study. 
	

  I would also ask for an example (just one) where any
> accepted physical law that has been changed on the basis on one,
> unconfirmed study.

	--Up to 1952, it was assumed that a neutron striking a nucleus was
certain to initiate a nuclear reaction; there were excellent reasons for
believing this. The experimental finding of giant resonances in neutron
cross sections changed that to "the cloudy crystal ball" model, now better
known as the 'optical model".
	I can give any number of other examples.

  If The Scientific Method is at stake, show us the history.
> 
	--I know of no example in physics where a theory survives after it
is shown to be in disagreement with experimental results. If there is no
experimental data supporting such a theory, it would be abandoned at the
first hint of disagreement with experimental data.
	Let me quote Richard Feynman on this point:

"...we look for a new law by the following
process: first we guess at it. Then we compute the consequences of the
guess to see what would be implied if this law we guessed is right. Then
we compare the result of the computation with ......observation, to see if
it works. If it disagrees with experiment [the law] is wrong. In that
simple statement is the key to science. It does not make any difference
how beautiful your guess is. It does not make any difference how smart you
are, who made the guess, or what his name is--- if it disagrees with
experiment it is wrong. That is all there is to it."

	In our case, the law that "was guessed at" is linear-no threshold 
for individuals in the low dose region,
and the consequences that were computed was the relationship between lung
cancer rates in counties and average radon exposures in those counties,
with suitable corrections for confounding factors. "Our discrepancy" is
that the computed relationship is very different from the observed
relationship.

> 
Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu