[ RadSafe ] risk question

[Otto G. Raabe]

At 05:20 AM 10/21/2013, you wrote:
>Acceptable radon concentration: 12pCi/l.
>Highest I would live in: 12pCi/l
>Colorado, USA
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October 21, 2013

Almost all lung cancer in the U.S. is related to tobacco smoke.
About 95% of cases are in smokers or people living with smokers.

Thomson et al. (Health Phys. 94: 228–241; 2008) showed that moderately
high levels of radon in homes are somewhat protective, apparently
interfering with lung cancer induction from smoking. The "optimum" levels
of radon in homes are from 150 to 250 Bq/m3 or 4 to 6 pCi/L. This is the
typical range in Colorado which probably explains in part why
Colorado has one of the lowest lung cancer rates of U.S States.
I think that the only States that are lower are Utah and Hawaii,
probably associated with low tobacco use.

In Health Phys. 98: 515-536 (2010) I showed that there is a virtual
threshold for alpha radiation induced lung cancer at a lifetime dose
of 10 Sv to the bronchial epithelium.

Otto

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Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754   FAX: (530) 758-6140
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