Iowa Radon Lung Cancer Study

[EPIRAD@aol.com]

radsafe@romulus.ehs.uiuc.edu
In a message dated 00-06-23 10:09:12 EDT, Mr. BORGER wrote:

In my rather naive understanding of the "Hill Criteria," I read,

  "The first Hill criterion is the strength of the association between 
exposure and risk.
  A strong association is one with a relative risk (RR) of 5 or more. 
Tobacco smoking,
  for example, shows a strong association, with a RR for lung cancer 10-30 
times that
  of non-smokers. A RR of less than about 3 indicates a weak association.
  A RR below about 1.5 is nearly meaningless unless it is supported by 
other data. "

  By my application, this indicates a weak to meaningless correlation for 
the highest
  exposure group in the state with the highest exposure in the nation.

  So I pose this question. How can one posutlate a STRONG correlation between
  Radon and Lung Cancer.

Perhaps we're dealing with wordsmithing akin to that done by our 
illustrious President? "It depends on what you mean by 'strong'"

---------------------------------------------
Response from Bill Field

Perhaps we are dealing with interpretation building on misinterpretation of 
published statements.

It is my guess Mr. Borger read Mr. Brook's previous posting and assumed Mr. 
Brook's statement was correct concerning our use of the word "strong".  Mr. 
Brooks had numerous misinterpretations of the AJE paper and made several 
erroneous statements.

We stated, "Analyses restricted to the 283 live cases and 614 live controls 
noted both a strong categorical (p = 0.01) and continuous trend (p = 
0.03).  The fifth exposure category was also statistically significant (OR= 
2.14; 95 percent confidence interval 1.12 - 4.15)."

It should be obvious from this statement that we were talking about the 
trend when we used the word "strong", not the odds ratios (relative risk).   
Mr. Brooks and Mr. Borger apparently failed to understand the difference.  
We did NOT say (as apparent from reading the quote above) the fifth exposure 
category found a 
strong association.

I maintain that our findings indicate residential radon exposure poses a 
significant risk for lung cancer.  I have been quoted in many newspapers 
and talks as saying that the risk posed by residential radon exposure pales 
in comparison to the risk posed by cigarette smoking (for example, see 
http://www.cancer.org June 21 story).  The risk posed by most carcinogens 
pale in comparison to the risk posed by smoking. That is why I spend much 
of my volunteer time in activities related to smoking cessation.   
Nonetheless,  
our findings indicate residential radon exposure is an important 
environmental 
risk factor for lung cancer that should not be ignored.

Regards, Bill Field

*******************************************

R. William Field, Ph.D.
College of Public Health
Department of Epidemiology
N222 Oakdale Hall
University of Iowa
Iowa City, Iowa 52242

319-335-4413 (voice)
319-335-4748 (fax)

mailto:bill-field@uiowa.edu

Iowa Radon Lung Cancer Study 
findings:  http://www.cheec.uiowa.edu/misc/radon.html

U.S. EPA View of the Iowa Radon Lung Cancer Study
http://www.epa.gov/iaq/radon/
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