410012 ‘R August 17, 1984 Mr. Edward T. Lessard Brookhaven National Lab. Upton, NY 11973 and 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 years. 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 ? ●