Re: US radiation safety limits not based on science-GAO

["Otto G. Raabe" <ograabe@ucdavis.edu>]

At 09:41 AM 7/17/00 -0500, Dave Derenzo wrote:
>Aren't the NRC limits for the public 100 mrem per for most of the 
>population and 500 mrem per year to a small fraction of the 
>population?  Where did the 25 mrem limit come from?  Where in the regs is 
>the EPA limit of 15 mrem found?
*******************************************
July 17, 2000
Davis, CA

I believe that the NRC 25 mrem annual limit assumes that a person might
have up to four other exposures per year from other sources, so this limits
the total for such a person to 100 mrem per year.

I believe that he EPA 15 mrem is based on a hypothetical mathematical
calculation of lifetime risk using a the standard LNT model. 15 mrem per
year times 70 years of life is about 1 rem which EPA believes represents a
lifetime cancer risk of one in twenty-thousand.

Otto

	*****************************************************
	Prof. Otto G. Raabe, Ph.D., CHP
	Institute of Toxicology & Environmental Health (ITEH)
	(Street Address: Bldg. 3792, Old Davis Road)
	University of California, Davis, CA 95616
	E-Mail: ograabe@ucdavis.edu
	Phone:(530) 752-7754, FAX:(530) 758-6140
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