Re: Cohen's Ecologic Studies

[RuthWeiner@AOL.COM]

Dear RADSAFERs:


The following may very well just be stupidity on my part, but I have been puzzling over it for some time:


A "confounding factor" seems (to me) to be some factor or parameter that confuses (confounds) an otherwise clear cause-and-effect relationship.  Thus, I do not understand how smoking, especially more than a pack a day for 20 years, can confound the relationship between lung cancer and radon exposure.  The causal relationship between lung cancer and heavy smoking has been clearly established, but a causal relationship between indoor radon exposure and lung cancer (pace Bill Field and the EPA) has not been,  I could understand the reverse statement -- that radon exposure might be a confounding factor for  establishing smoking, or eve second hand smoke exposure, as a cause of lung cancer.  


I can see, for example how smoking can be a confounding factor in the relationship between black lung in miners and mine dust exposure, or in the relationship between asbestos exposure and asbestosis IN ASBESTOS WORKERS, but I don't understand how a factor that has been established as a primary cause of a disease can confound the relatioship between that disease and a secondary, not-well-established, somewhat speculative factor.


Can someone explain this, please, in some way other than with statistics?  I have nothing against statistics, but they show correlations, not causes.  Looking at correlations alone, it is perfectly possible to draw the wrong conclusions about causes, as in  the following canard: 


Q:what is it in a highball, a gin-and-tonic, and a scotch and soda that gets you drunk?  

A: it must be the water, because they all contain more water than anything else.



Ruth Weiner, Ph. D.

ruthweiner@aol.com