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Re: Radon and Lung Cancer: What the studies really say.
People living in counties that have high average radon concentrations
have fewer lung cancers than people living in counties where the average
radon concentration is lower do.
------------------------
This is huge oversimplification of the Cohen's data and has no relationship to
the risk posed to residential radon exposure.
It can also be stated that -
People who live in high radon counties smoke less etc, etc.
Until the inter county variability of smoking and correlated factors are
adjusted for, these generalizations are meaningless.
> Friends,
>
> We are all aware that ecological studies, in general, have some limitations.
> Similarly, many of the case control studies have some very specific
> problems. Both of these issues have been discussed (some would say ad
> infinitum) on this board and elsewhere.
>
> For this thread, I'd like to assume that the authors of both types of study
> know their craft and are able to collect data and make some very basic
> adjustments and stratifications. The studies then tell us:
>
> 1. People living in counties that have high average radon concentrations
> have fewer lung cancers than people living in counties where the average
> radon concentration is lower do.
> 2. People who had high cumulative radon exposures in the past have more lung
> cancers than people who have been exposed less do.
>
> Some people have stated that the conclusions that follow from these
> statements cannot both be right. Clearly, this is wrong. There is probably
> an infinite number of dose response functions that are consistent with both
> observations. None of these functions requires the presence of hidden
> confounders. The obvious one that I can think of is:
>
> --> High radon in your own house is bad for you and high radon in your
> neighbor's house is good for you.
>
> Radon in your own house represents chronic exposure and high radon in your
> own house will result in a high cumulative exposure. On the other hand, you
> are only exposed to the radon in your neighbor's house for a few hours at a
> time.
>
> Is there any reason why we should assume that the beneficial effects of
> radiation exposure are dependent on cumulative dose? Can anyone name a
> beneficial agent where the amount of benefit is related to cumulative dose
> alone? Other beneficial stressors (e.g. exercise) deliver their benefit most
> effectively if the stressor is applied for a short time and is followed by a
> period of relaxation. This is exactly the temporal variation in radon
> exposure that someone living in a low radon house in a high radon county
> would experience.
>
> Kai
> http://www.eic.nu
>
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