August 17, 1984

Mr. Edward T. Lessard
Brookhaven National Lab.
Upton, NY 11973


Dr. William L. Robison
Lawrence Livermore National Lab.
P. O. Box 808
Livermore, CA 94550

Dear Ed and Bill:
A major problem in determining whether there is, indeed, a discrepancy
between your estimates of the radiation doses from plutonium (and americium) to the people who lived at Bikini for about seven years is that you
use different methods and calculate different doses to different tissues.
For example (see pages 44, 45, 48 and 49 in UCRL-53225 and page 68 in NCRP
Annual Meeting Proceedings No. 5), Bill calculated 30-year and 50-year
integral dose equivalents to mineral bone and divides by 4 to obtain the
bone marrow dose equivalent (Table 28 on page 45 - the inhalation values
appear to have decimal point error).
It is not clear whether a quality
factor of 10 or 20 was used. These are estimates of the dose equivalents
that would be received if people lived on Eneu or Bikini the next 30 and 50
On the other hand, Ed calculated 50-year committed dose equivalents to bone
surfaces (not average doses to mineral bone), red marrow, liver and gonads
and also calculates the effective committed dose equivalent.
I assume a Q
of 20 was used. These values also include weighting


Select target paragraph3