fivery effort was made to maintain uniform procedures In every phase of the libocatory work, The number of personnel changes for a given procedure was held to a minimuin; personnel drawing blood [rom a single puneture were sufficient tn number to allow all samples to be taken in rapid successign. 4.3. All time intervals were rigidly controlled. METHODS OF TREATING DATA, CONTROL GROUPS Pre-exposure blood counts were not available on the exposed Marshallese or Americans; hence the individuals could not be used as their own controls. In order to estimate the severity of the hematologic response it was necessary to establish control groups as comparable as possible in respect to age, race, sex, background, and habits. A Marshallese contro! group living on Majuro, comparable with respect to age and sex to the Rongelap people, was used as Table 4.4 HEMATOLOGICAL RESULTS, CONTROL GROUPS Hematocrit® Control Group Miaguro Kwa)- Age No. in WC Neutrophiles Lymphocytes Platelets (yr) Gp. (s 10%) 0-5 22 13.2 4.8 7.4 38.8 6-15 14 10.6 4.68 5.1 38.6 38.5 37.3 (10) (12) 41.3 40.6 Ib- 50 63 9.4 4.8 4.0 30.9 46.8 40.4 43.3 / 50 14 9.6 5.0 3.7 30.7 ms) 91 9.7 4.8 4.1 43.6 41.8 (10) (4) 4522 40.6 43.0 (14) <15 37 ts) 16 >18 28 (x 0) (x 105) . (> 109 (Per Cent) 33.6 M KF (6) (8) (29) (34) Comb 378 (22) 40.9 (4) (G3) 38.5 4.1 3.1 23.8 tt 44.9 Americans *Numbers in parentheses indicate number of individuals in the group. the Marshallese control group. For comparison with the exposed Americans, blood counts were made on approximately 85 American males, on duty at Kwajalein. All who had not been on duty in the tropics for more than two months were excluded since the exposed Americans on Rongerik had been in the area for about two months before exposure. In addition several who were recently associated with radioactive materiais were excluded. The resulting smaller group of 67 was used as the Kwaj-American control group. Preparatory to analyzing the hematological results on the exposed Marshallese, data from the control Majuro Group were examined to determine if there was an age or sex dependence. in the hematologic observations (Table 4.1). Although the neutrophile count was independent of age, the lymphocyte counts were significantly higher in children below the age of 5. Similarly the platelet count was higher in the younger age groups; however, a relative depression appeared to occur at about age 15. The total leukocyte, neutrophile and lymphocyte counts were independent of sex. The hematocrit of females was lower than that of males, particularly in the child bearing age group. The age and sex dependency of these endpoints is comparableto that in published data.™-*? To obtain valid comparisons within and among the various exposure groups, they were stratified in accordance with age or sex dependency noted for the control groups, Although each individual] in all groups was studied. hematologically, those Marshallese with serious long-~standing diseases were omitted from the analysis. A total of two from the Rongelap and two from the Majuro groups were omitted on this basis. e aan . eoorne , 64 . - Fe 30.8 7.8 .