,? 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 wags 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 4.1 HEMATOLOGICAL RESULTS, CONTROL GROUPS eei Contrel Group Mayuro Kwaj- Age Hhematocrit* No. in (Per Cent) lyr) Gp. (* 103) Whe Neutrophiles Lymphocytes Platelets (~~ 104) M F- Comb -5 22 13.2 4.8 7.4 38,8 36.5 37.9 37.8 (kO) (42) (22) (x 10) (x 105) b-15 14 10.6 4.8 5.1 38.6 41.5 40.0 40.9 bh - 50 6 Y.4 4.8 4.0 30.9 (6) 46.8 (s) 40.4 (14) 43.3 ~5O 14 9.6 5.0 3.7 30.7 43.6 41.5 43.0 91 37 9.7 4.8 4.1} 33.6 38.5 (10) 45.2 (4) 40.6 (14) 2S 15 18 76 >18 28 (29) (34) (63) 30.8 7.8 4.1 3.1 23.8 = 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 Ronperik had been in the area for about two months before exposure. In addition several who were recently associated with radioactive materials were excluded. The resulting smaller group of 67 was used as the Kwaj-American control group. Preparatory to analyzing the hematological resulls 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 comparable to 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 longstanding diseases were omitted from the analysis. A total of two from the Rongelap and two f~1m the Majuro groups were omitted on this basis. 7 | mere rye oats eaepee poeeored eeopee * eepene . 64 + a 4.3. ee Every effort was made to maintain uniform procedures in every phase of the laboratory work, The number of personne! changesfor a given procedure was held to a minimum, per sonnel drawing blood from a single puncture were suffictent in number to allow all samples te be taken in rapid succession. All (ime intervals were rigidly controlled.