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RE: Apparent anti-correlations between geographic radiation and cancer are no...



Kai,
No, you are not looking at tens of millions of excess cancers.  What you are looking at is a map of reported cancer cases normalized to a certain population value.  You are reading too much into the maps, and need review the origianal report before making any startling statements.  I believe that some of the values are rounded, some are estimates, etc.  I think you are putting too much faith into the accuracy of the values. 
 
Second, there are a lot of confounding factors that are not even evident in the data.  For example, a lot of people move to Arizona when they retire, but do not stay there the whole year.  They are called snowbirds.  In the summer they travel up north to die.  (My daughter lives in Phoenix, so she has an idea of what is going on.) 
 
I think you have to accept the fact that there is more here than just colors and numbers. 

-- John

John P. Jacobus, MS
Certified Health Physicist
e-mail:  jenday1@msn.com

The comments presented are mine and do not reflect the opinion of my employer or spouse.
------------------------------------

 
-----Original Message-----
From: Kai Kaletsch [mailto:eic@shaw.ca]
Sent: Thursday, January 02, 2003 1:43 PM
To: RuthWeiner@AOL.COM; radsafe@list.vanderbilt.edu
Subject: Re: Apparent anti-correlations between geographic radiation and cancer are no...

Ruth,
 
If migration of retirees is responsible for excess cancer mortality, then a map of retiree migration should match the cancer map. I kind of doubt that it will. Lots of old people move to Arizona, but cancer incidence seems low throughout the sate.
 
You think the reason the cancer map looks like it does is because of migration, John thinks its because of population density, someone else thinks its because of diet or a combination of factors. All I'm saying is that it is worthwhile to figure out what it is. We are looking at tens of millions of excess cancers here. 
 
We are at least 3 orders of magnitude larger than what would be expected from statistical fluctuations. Therefore, something causes the map to look like it does. It should be possible to map a causal factor, or a mathematical function of factors, to reproduce the features of the map. Otherwise, we have to admit to ourselves that we are pretty clueless.
 
Regards,
Kai
 
 
----- Original Message -----
Sent: Thursday, January 02, 2003 9:58 AM
Subject: Re: Apparent anti-correlations between geographic radiation and cancer are no...

In a message dated 1/2/03 8:36:00 AM Mountain Standard Time, eic@shaw.ca writes:

The map http://www.dceg.cancer.gov/cgi-bin/atlas/mapview2?direct=acccwm70 doesn't seem to support that conclusion. It may also be that "cancer clusters" are usually considered a few incidences of very rare forms of cancer. I think the biggest leukemia cluster has about a dozen or two cases. These "clusters" would not show up on a cancer map that deals with millions of cases. I don't know what the New Yorker article meant by clusters. (Us healthy prairie folk only read fishing magazines, if we read at all.)
 


The map is a map of cancer mortality, not incidence.  While it is age-adjusted, it does not provide the fraction of deaths that are cancer deaths, and generally seems to follow both population and total mortality (e.g., Las Vegas, NV has a growing population of retirees, so the number of people who die there increases, and thus, as anticipated, cancer mortality would increase).  I don't think one can draw any conclusion about the cause of cancer from such a map.

Ruth


Ruth Weiner, Ph. D.
ruthweiner@aol.com