DFFICIAL USE ONL— Dr. Richmond also described briefly the studies that have been conducted on a group of 25 workers who have been followed since 1953. All these workers had significant body burdens of plutonium. Drs. Langham and Hempelmann are conducting these studies. To date, there have been no abnormalities encountered. Dr. Richmond also mentioned briefly the continuing study of plutonium levels in unexposed residents in the Los Alamos community. This work was started years ago, when Dr. Lushbaugh was the pathologist at the Los Alamos Hospital, in collaboration with the industrial hygiene group. The work is continuing and is being expanded to include persons from other areas, The Committee adjourned and reconvened at 8:30 A.M., Saturday, January 8, at the "H" Street office. The first order of business was completion of the briefings that had been scheduled for Friday but for which there was inadequate time. Dr. Beasley of the DBM staff described DBM-supported studies on plutonium in lakes and oceans. There are three contracts for studying plutonium in oceans, Two of these are at Woods Hole and the third is at the Scripps Oceanographic Institute in La Jolla. Old studies have indicated a very high concentration factor for plutonium in marine organisms. This is principally in the very simple organisms. As it moves up the food chain, the concentrations drop very drastically because of discrimination against the uptake of plutonium. The studies indicate that plutonium on the ocean floors is moving deeper into the sediment and becoming entrapped. There are also some studies being conducted on plutonium in the Great Lakes. Dr. Beasley also reported briefly on the cleanup of the Bikini Atoll. Dr. Conard, of the Brookhaven National Laboratory, will be following the Bikini population as well as the people who were exposed on Eniwetok. There are little data available on the early levels of plutonium for either the Bikini or Eniwetok Atolls, DBM is considering initiating some research on plutonium on Bikini but as yet there is no program underway. Dr, Watters, of the DBM staff, described the collaborative studies between Colorado State University and the Rocky Flats plant. The people at Colorado State are studying the movement of plutonium from contaminated wounds using dogs. The wounds are simulated by using a subcutaneous injection of plutonium. The Rocky Flats plant provides the analysis of tissue samples from various parts of the body. Dr. Wood, of the DBM staff, gave an overview of the activities in instrumentation as it applies to the assay of plutonium and the estimation of body burdens. A proposed method of in vitro assay of plutonium is to layer the appropriate material on plastic, expose this material to a neutron flux which then results in fission fragments which damage the underlying plastic. On etching the plastic it is possible to count the number of fission fragments produced and from known cross sections, the neutron flux, etc., it is possible to estimate the amount of plutonium present. This is a very sensitive system. The current method of estimating body burdens in living subjects is by -9- OFFICIAL USE ONLY