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Re: Radon and Smoking
My point was addressing Kai's hypothesis that radon is lower
in smokers' homes because they open their windows more. But, if the
difference in radon levels between smokers and non smokers homes decrease
with increasing cigarette use, that does not support Kai's
hypothesis. The difference is probably due to the fact that urban
dwellers have lower radon and also smoke more.
You may not have claimed that increased sample size eliminates biases in
an ecologic study, but that has been inferred repeatedly by others on the
list.
Bill Field
At 11:27 AM 2/14/2002 -0500, you wrote:
On Wed, 13 Feb 2002, Field, R.
William wrote:
> Dr. Cohen,
>
> As I have stated before, validity of findings is not a matter of
numbers.
> While I do not agree with all of NCRP No. 136, I do agree with
the
> following quote from NCRP concerning the limitations of ecologic
studies:
>
> "Use of large numbers of geographic regions will not do away
with
> biases. More observations will generally increase precision
but have
> little or no impact on validity, i.e., the degree of
bias." In other other
> words the observation can be precisely wrong.
--I have
never claimed that good statistics eliminates bias; the
two have nothing to do with each other.
>
> What I find interesting is this quote in your 1991 paper:
>
> "The results in Tables 2 and 3 clearly indicate that households
with
> cigarette smokers have substantial lower Rn levels then others, but
for
> some strange reason it seems that the difference decreases with
increasing
> number of cigarette smoked. It should be noted that from those
tables that
> only 17% of all people who purchased Rn measurements have smoked in
their
> households, whereas 33% of American adults are
smokers."
--It is
not clear to me what you are trying to prove
here.
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