samples for radiochemical analysis: These studies are not yet complete and have not been included in this report. The Navy kindly furnished a ship for the ex- lese, particularly in the older age group, are uncertain of their exact ages, largely because few written recordsof birth are maintained. 3). The LST picked up medical equipmentfor the Comparison Populations pedition, an LST, the USS Plumas County(Figure survey, including a 21-ton steel room for carrying out whole-body counts on the Rongelap people, about the middle of February at Hawaii and proceeded to Kwajalein. The medical team staged in Hawaii and flew via militaryair transportation to Kwajalein, boarded the LST, and proceeded to Rongelap Atoll. At Rongelap the LST was beached for easy accessibility to Rongelapvillage. The 21-ton steel room, constructed at Brook- haven National Laboratory for use in whole-body gamma spectroscopy on the Marshallese in this and future surveys, measured 5 ft 8 in. by 5 ft 8 in. by 6 ft 6% in., with 4-in.-thick walls and ceiling and a 2-in.-thick floor. The room had beenset up in the tank deck of the LST along with two 100- channel analyzers, a 5-in. crystal, and other accessory electronics equipment.’ A dressing room and showerfacility had also been constructed on the tank deck for decontamination of personnel prior to whole-body counts. (See Figures 4 and 5.) The histories were taken, and the physical and laboratory examinations were carried out at Rongelap village in the dispensary, school building, and council house (see Figure 6). The examinations lasted 3 weeks. Difficulties Associated with the Examinations Several difficulties associated with carrying out the examinations as well as interpreting the findings should be pointed out. 1) The language barrier made examinations difficult since very little English is spoken by the Marshallese. However, there were sufficient English-speaking Marshallese to assist the medical team in most instances in carrying out the examinations. 2) The lack of vital statistics or demographic data on the Marshallese imposed a seriousdifficulty in interpretation and evaluation of the medi- 3) It is unfortunate that many of the Marshal- Duringthe first 2 years, two separate groups of Marshallese people were used for comparison, each of comparablesize to the exposed Rongelap group and matchedin age and sex. However,this population was found to be unstable, with a large attrition rate over the 2 years, which madeit unsatisfactory. At the time of the 3-year survey,it wasfoundthat during the preceding 12 months the Rongelap population at Majuro Atoll had doubled becauseofthe influx of relatives who had come back from otherislandsto live with them. These people. had been away from Rongelap Atoll at the timeof the accidental exposure. This group matched reasonably well for age and sex and was of comparable size; moreover, since these people were of the same stock genetically, they proved to be uniquely appropriate to serve asa comparison population. This group wastherefore used at the 3-year examination as a control and again during the present survey. PROCEDURES History and Physical Examinations Histories were taken by a Marshallese practitioner with particular emphasis on the interval history during the past year. Complete physical examinations were carried out including examinations of the children for growth and development, anthropometric measurements, and x-ray examinationsof theleft wrist and handfor bone developmentstudies; special examinations of the skin with color photography for selected lesions; ophthalmological studies including slit-lamp observations, visual acuity, and accommodation; and EGC and x-ray examina- tions as deemed necessary. cal data. Recordsofbirths, deaths, etc., have been Laboratory Examinations administrator; however, such records have been platelet counts (phase microscopy}, and hemato- made by the health aides or magistrates of the villages and supposedly forwarded to the district poorly kept or lost in most instances and thusvital statistics are practically nonexistent. Trust Terri- cS Lod Pwo CH cs tory officials are now attempting to assemble such data. Hematological examinations included three complete blood analyses with WBC, differential, crit (microhematocrit method) done at about weekly intervals. The following examinations of the blood were made to determinegenetically determinedtraits.