N-4A The following letter is from Dr. W. H. Adams of Brookhaven National National Laboratory to Dr. Roger Ray of DOE. — 2108 July 18, 1985 Mr. Roger Ray Deputy for Pacific Operations Nevada Operatlons Office Department of Energy P.0. Box 14100 Las Vegas, NV 869114 Dear Roger: In view of the recent evacuation of Nongelap, which appears to have heen precipitated by concern about harmful residual radioactivity on the atoll, we have reviewed our medical records to see if there is any clinical evidence that supports thls conclusion and course of action. Since 1957 an unexposed population of Harshallese of Rongelap ancestry has been examined periodically by the Urcokhaven medical team. This population (the Comparison group) is similar in age and sex distribution to the exposed people of Rongelap. The reason for examination of the unexposed group has been to obtain baseline incidences of diseases in the general Marshallese population as an aid in detection of previously unidentified radiation hazards which might affect the exposed group. | ColJected data on the unexpused penple are sufficient to assess the effect of residence on Rongelap (since 1957) on longevity, thyrold neoplasia, and blood counts. We have done a retrospective analysis of their medical records; %33 of the group are Jiving and 54 are deceased. We have arbitrarily selected for analysis the following divisions of years of residence on Rongelap: Short-term - <3 years (average, 1.0 years) Long-tera = Intermediate - 4 - 14 years (average, 7.5 years) >15 years (average, 20.9 years) The place of residence for a given year is defined as the place where an individual recelved his medica] examination. Since there is considerable migration of Marshallese among the atolls, the site of examination may not always be the same as the site of residence. Overal], however, there should be a good correlation between the two. 57