282 CONARD ET AL. B. Lasorarory EXAMINATIONS Hematological examinations included three complete blood analyses (total white counts, differential, platelet counts by phase microscopy, and hematocrit by the microhematocrit. method) done at about weekly intervals. Sera were obtained for total protein determinations by proteinometer, protein-boundiodine, and starch electrophoresis studies. An intestinal parasite survey of the population was carried out by examining the stools of 190 people for ova and parasites. Pooled urines and a few sufficiently large samples from single individuals were obtained from both the exposed and the unexposed groups for radiochemical analyses of Cs” and Sr”. Whole-body counts with y-ray spectroscopy were obtained on board the ship by placing the individuals in a steel room with 4-inch-thick walls, with the necessary crystals and electronic equipment attached. ©. DireicuLries AssOCIATED WITH EXAMINATIONS Several difficulties associated with the examinations of the Marshallese should be mentioned: 1. The language barrier made the examinationsdifficult, since very little English is spoken by the Marshallese. Sufficient interpreters were available to assist the medical team, however. 2. The lack of vital statistics to be found on the Marshallese imposes a serious difficulty in interpretation and evaluation of the medical data. 3. The uncertainty of exact ages of some of the Marshallese, largely due to lack of written birth records, came to light during the past examinations. It is hoped that these ages may be established more firmly so that the growth and development studies in the children may be placed on a firmer basis. 4+. Difficulties arose in obtaining what could be considcred as entirely adequate popu- lations to act as comparison groups for the irradiated people. Three separate groups have been used for comparison in the past. Though each group matched well for age and sex, the first two groups proved unsatisfactory owing to difficulties in locating the people for subsequent examinations. Fortunately, by 3 years postexposure, it was found that a large group of Rongelap people who had been away from their home island at the time of the accident had returned to live with their fellow Rongelap people. Because they were of the same stock and matched reasonably well for age and sex, these people were uniquely appropriate to serve as a comparison population. They returned to Rongelap with the other Rongelapese and were used again as the comparison population for the 4-year survey. III. RESULTS at Lad to The description of the present status of the Marshallese people will be preceded by a brief summary of the past findings. During the first 24 to 48 hours after exposure, about two-thirds of the Rongelap people experienced anorexia and nausea. A few vomited and had diarrhea. At this time many also experienced itching and