Re: Radon and Lung Cancer: What the studies really say.

[Kai Kaletsch <eic@shaw.ca>]

Howard,



Any valid theory should be able to explain all data, unless there were

serious mistakes made in collecting the data. Even then, we should be able

to put an upper limit to the effect of the mistakes and our theory should

match the data to within that error.



The point is that the case control studies and the ecological studies use a

different x-axis. One is personal radon exposure, the other is average

county radon level. Because most people do not grasp the significance of

this difference, we have statements from learned people and prestigious

organizations saying that the result of the ecological data is not

compatible with the result of the case control studies. This is, of course,

complete and utter nonsense. Cohen's results do NOT imply a negative slope

between personal radon exposure and lung cancer.



If you want to check the validity of Cohen's results with a case control

study, you have to use the same metric (AKA yardstick). You have to plot

your cases and controls against the average radon level in the county of

residence, not against their personal exposure. This could easily be done

retrospectively for the existing case control studies and it would not cost

a whole bunch of extra money. It would probably be most informative if it

was done for a state where lung cancer incidence is high and there is a

large variation in radon levels among counties. Iowa would probably not be

the best candidate, but I'd still like to see the results.



Kai



----- Original Message ----- 

From: "howard long" <hlong@pacbell.net>

To: "Kai Kaletsch" <eic@shaw.ca>

Cc: "'RADSAFE'" <radsafe@list.vanderbilt.edu>

Sent: Thursday, June 19, 2003 9:02 AM

Subject: Re: Radon and Lung Cancer: What the studies really say.





> Kai,

> Does Field's Iowa being out in right field on Cohen's U curve (1% outlier)

> help understand their different perspectives?

>

> Howard Long

>

> ----- Original Message -----

> From: "Kai Kaletsch" <eic@shaw.ca>

> To: "BERNARD L COHEN" <blc+@PITT.EDU>; <epirad@mchsi.com>;

> <radsafe@list.vanderbilt.edu>

> Sent: Wednesday, June 18, 2003 12:42 PM

> Subject: Radon and Lung Cancer: What the studies really say.

>

>

> > 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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>



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