Fwd: Re: Fwd: query

["Thatcher, Drew" <dht0303@hub.doh.wa.gov>]

I believe the number works out to be quite a bit less if one uses the 
conversion factor provided in ICRP 65 of 4 mSv/WLM.  Assuming 0.4 for an 
equilibirum fraction, 7,000 hours/y exposure time, and 46 Bq/m^3, I get a 
value around 0.8 mSv/y, or 80 mrem/y.

Sincerely,
Andrew H. Thatcher, MSHP, CHP
Washington Department of Health
360-236-3255 voice*
360-236-2255 fax*
dht0303@doh.wa.gov
*new number                  

                  ***** Original Message Follows *****

	Many thanks. I had not realized that NCRP-93 was based on 1.0
pCi/L average exposure. I looked it up and it was based on 40 Bq/m3
(1.08 pCi/L). Since the correct value is 1.25 pCi/L, that means
that the average U.S. exposure is increased from 200 mrem/y to 230 
mrem/y.
Does anyone disagree on that?

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Thu, 26 Feb 1998, Thatcher, Drew wrote:

>                   ***** Original Message Follows *****
> 
> 	Is there anything more recent and authoritative for summarizing
> average annual radiation exposure in U.S. than NCRP-93 (published in
> 1987)? Are any of the figures given there changed by later info?
> 
> Bernard L. Cohen
> Physics Dept.
> University of Pittsburgh
> Pittsburgh, PA 15260
> Tel: (412)624-9245
> Fax: (412)624-9163
> e-mail: blc+@pitt.edu
> 
> I performed a literature search  about a year ago trying to locate more 

> recent estimates that would take into account the radon gas conversions 

> provided in ICRP 65.  I was unable to find any.  I've had on the back 
> burner a simple update that uses the same equilibrium factor (0.4) but 
> wanted to try and obtain a better picture of the average U.S. indoor 
> radon concentration.  The NCRP uses a value of 1.0 pCi/L and I wanted 
to 
> make sure this was still appropriate.  Is this along the lines of what 
> you are looking for?
> 
> Sincerely,
> Andrew H. Thatcher, MSHP, CHP
> Washington Department of Health
> 360-236-3255 voice*
> 360-236-2255 fax*
> dht0303@doh.wa.gov
> *new number                  
> 
> 
> 
>