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

[Kai Kaletsch <eic@shaw.ca>]

From: "BERNARD L COHEN" <blc+@pitt.edu>



> --It is very widely agreed that a measurement of radon

> concentration in a home give an estimate of its occupants' exposure to

> radon progeny. The usual conversion is 0.2 WLM/year per pCi/L.

> This is used in essentially all case-control studies as well as my

> studies, and in estimates by EPA and other agencies.



Your data is in terms of lung cancer vs. average county radon level NOT lung

cancer vs the radon concentration in the patients house and you do not

multiply the concentration by time to get an exposure. (0.2 WLM/year  is

also not a unit of exposure. It is a unit of exposure rate.)



Any structure that you see in your graph could be due to only the people in

10 pCi/L houses. You have no way of knowing. The structure could also be due

to the people who have a neighbor who has a 10 pCi/L house.



Most of what I read on animal experiments that shows a beneficial effect of

radiation requires a specific sequence in which the dose is administered and

is not related to cumulative dose. The latest one required a single dose of

10 to 100 mGy delivered at 0.5 mGy/minute to mice. It also makes more sense

to me that you need an acute dose, strong enough so that the body notices

that an exposure has occurred, to initiate an adaptive response, rather than

a low chronic exposure. Why would you assume that the clear benefit that you

see in your lung cancer vs county radon graph has anything to do with

cumulative dose?



Kai



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