56 EFFECTS OF IONIZING RADIATION Table 4.10.—Characteristics of Available Data on the Hematological Effects of Penetrating Radiation CHARACTERISTICS Numbers in groups.__| Adequacy of Con- trols Serial counts._______ Counting techniques* Chance of bias due to sampling techniques “Normal” individuals Internal nation contami- Additional trauma (burns, ete.) Species extrapola- JAPANESE BOMBINGS CLINICALRapro- LABORATORY AccI- EXPOSEDMARSHAL- large small small large large no fair ves fair yes good yes good yes good large large large small small yes no yes yes ves none none none minimal none yes no yes yes no no no no fair tion necessary Type of radiation___| gamma, poor some neutrons hard poor X-rays, gamma good gamma, neu- trons, X- Dosage estimation___! poor good Single exposure. .___ Dose rate_________- yes Instantaneous usually no ~5r/min. yes Instantaneous Body region_____.__ Total body Dosage range_____._ Sublethal and lethal Narrow beam Moderate fall off Usually partial body Sublethal Total and partial body Sublethal and lethal Narrow beam Rapid fall off Narrow beam Variable very good no rays, betas poor Geometry__________ Depth dose eurve LARGE ANIMALS gamma, yes beta to skin hard X-rays, gamma fair good yes Varying ~5r/ hr. yes ~10r/min. Total body; beta to skin Sublethal 360° field Essentially flat Total body Sublethal and lethal Narrow beam Variable; rapid fall off to flat *Same technicians for all counts; rigidly standardized techniques throughout, ete. 4.42 Comparison With the Japanese Hiroshima and Nagasaki Data The limitations stated in Table 4.10 apply to the Japanese low dose groups* E to H in particular, in which values given (Oughtersenet al. (12) and Le Roy (13) ) are pooled and include individuals located at the time of the bombing *The Japanese casualties were divided into groups ‘A to Hoon the basis of degree of exposure as determined roughly by distance from the hypo-center and approximate degree of shielding. In groups E te H essentially ono mortality ascribable to radiation exposure occurred in the first 3 or 4 months. such that they may not have received significant exposure. Hence, while the pattern of change with respect to time is of value, absolute counts probably are high. The time course of hematological change in the people of Group I correspond most closely with these low exposure Japanese groups in which definite signs of severe radiation exposure were present in some individuals but in which essentially no mortality occurred (initial hematological studies on the Japanese terminated at 15 weeks). The early period up to approximately 6 weeks was characterized by considerable variation in total white count in both the Group I and Japanese