ov HEMATOLOGIC OBSERVATIONS Table 4.11.—Mean Peripheral Blood Count Values for Several Control Populations (x10°) SOURCE oF Data DETERMINATION 1 JAPANESE, RUBE 1947-1948 1948-1949 9.9 5.5 2.9 9, 5 5. 0 2. 8 (18) Total White count._____Neutrophile__._..------Lymphoevtes___.______- Monoevtes_.. 22-2 eee Eosinophiles_.. 2. .-_-__-Basophiles__.__________. Platelets__._____.2_ 2 - 0. 6 0. 9 — — (19) 0. 6 1.0 0. I — _ AMERICANS* ‘ (3) 7. 4 4. 4 2.5 0. 3 0. 2 0. 0 — AMERICANS, Kwal : CONTROL (2) AMERICAN controts GRouPA 7.0 4,3 2.1 7.8 4,1 3.1 9. 7 4.8 4.1 0. 4 0. 2 0. 0 **250 0. 3 0. 3 0. 0 238 0. 2 0.5 0. 1 308 *Age 21 years. **The mean value for 50 normal young American men, using the technique employedin the present study, was 257,000. cut ‘asualties. This fluctuation may be associated with the presence of thermal or other injuries im the Japanese or the active skin lesions in the Marshallese, or may correspond to the “abortive rise” noted for animals following exposure (14, 15). From the 6th week until the term1nation of the acute studies on the Marshallese during the 10th week, the Japanese and Marshallese counts remained at similar levels. The neutrophile count in both the Japanese and Marshallese in general paralleled the total white count. The lymphocyte count in both groups was depressed early and remained depressed at values of approximately 2000 until week 10. The high value of 2692 reported for the Japanese for weeks 12 to 15 must be suspected of being igh for the reasons given earlier. Various characteristics of the Japanese hematological trends should be pointed out: a) while high dose exposure groups with significant mortality showed an early depression with au definite low point at + weeks, the lower dose groups showed no definite mmimumat + weeks but rather a continued depression until the 8th or 9th weeks. b) While mean leukocyte counts of the heavily exposed groups had recovered in part and were approaching normal ranges, 381712 O—56——5 these means, 15 weeks after exposure werestill below means for control populations listed in Table 4.11. In fact, data of Kikuchi and Wakisaka (22, 23) indicate that hematologic recovery was not complete 2 years after exposure. The studies of these authors, performed independently of the Joint Commission and Atomic Bomb Casualty Commission, suggest the early blood response and prolonged recovery of the Japanese was similar to that reported here for the Marshallese. The present findings in the Marshallese are in accord with these characteristics, namely a) total white cell and neutrophile counts showed no definite minimum at 4 weeks as evidenced in Japanese groups A to D, but rather fluctuated during the first weeks with minimum mean counts occurring in the 6th week or later, b) neutrophile counts were unstable over the first 5 weeks, and recovery to control levels was not complete by the 6th month, c) lymphocyte counts remained depressed throughout the period of observation. Platelet data in the Japanese are not sufficient to allow more than rough qualitative comparisons. This is unfortunate since changes in platelet counts in the present studies ap-