Re: A radiation unit for the public

["David W. Lee" <lee_david_w@lanl.gov>]

	John Cameron's BERT proposal, to my understanding, is constrained to talk
in terms of "effective" dose (ED), because, since dose is used as a
surrogate for risk since the advent of the ICRP 30 "risk" based system, ED
includes the appropriate tissue weighting factor which, in effect,
expresses a localized organ/tissue dose as an equivalent whole-body dose.

	It's certainly true that the total natural radiation background varies
from region to region.  But I perceive that John's BERT proposal remains
quite viable even if one uses "average," even rounded figures.  Since NCRP
93, p. 53, states that the annual ED to a member of the US population,
averaged over the entire population, is approximately 360 mrem which
includes the average ED contribution from radon, then I suspect that John
would be quite satisfied if we, as HPs, would simply figure that a member
of the public sustains approximately 1 mrem ED per day from natural
background.  So, taking the example of a dental bitewing, according to the
CRCPD Publication 92-1, for fast (E-speed) film, the entrance skin exposure
at 70 kVp ranges from 120--170 mR (mid-point = 145 mR).  Assuming
approximately 0.92 rads/R for 70 kVp x-rays, then 145 mR X 0.92 = 133 mrad.
 The skin would be a remainder organ, wsubT = 0.06, so (0.06) (133 mrad)
(QF = 1) = 8 mrem which equates to approximately 8 days of natural
background, etc.

REGARDS David








At 03:06 PM 25-09-97 -0500, you wrote:
>Three cheers for Cameron.  Its been 101 years since Bequerel discovered
natural
>radioactivity.  And for 101 years the subject has been studiously omitted
from
>discussions of our natural environment.  And after 101 years 95% of the
general
>public couldn't give a 2 minute discussion of natural radioactivity, its
>sources, decay modes, decay energies, or provide comparisons with other
>sources.  
>People need to more about their natural environment, including the
>radioactivity that's been there for about 5 billion years.   Cameron's idea
>helps.  Public ignorance has caused a great deal of harm and has cost tens of
>billions. 
>
>Cameron's idea would not only be intellectually beneficial to the public, and
>worthy educational goal by itself.   It would also help the public
identify how
>they are being fleeced financially by private and public interests
pandering to
>public fears of radiation.  It would also aid the citizenry immeasurably by
>identifying who has been participating and who has been benefiting in the
>fleecing.  Its not a pretty story for a technological nation.
>MFox
>------------------------------------------------------------
>                The American Council on Science and Health
>        1995 Broadway, 2nd Floor   New York, NY 10023-5860
>                  Tel: 212/362-7044    Fax: 212/362-4919
>                                   http://www.acsh.org
>------------------------------------------------------------
>
>
>
David W. Lee
Los Alamos National Laboratory
Radiation Protection Services Group (ESH-12)
PO Box 1663, MS K483
Los Alamos, NM  87545
PH:   (505) 667-8085
FAX:  (505) 667-9726
lee_david_w@lanl.gov