200 to 230

[FRAMEP@ORAU.GOV]

Bernard Cohen wrote:

>        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?

The NCRP notes that the calculation of the 200 mrem has an uncertainty
of plus or minus 50% just based on the uncertainties of going from WLMs
to a dose to the bronchial epithelium and going from there to an effective
dose equivalent. Given the magnitude of this uncertainty alone,  is
refining the 200 mrem upwards to 230 appropriate?

Paul Frame
Professional training Programs
ORISE
framep@orau.gov