1160 



RADIATION BIOLOGY 



implanted as metal subcutaneously (Lisco and Kisieleski, 1953) the 

 majority of the animals appeared to suffer no ill effects from the local 

 implants or from the absorbed plutonium. When plutonium was injected 

 as citrate or phosphate intramuscularly or intravenously into rats, it 

 induced osteogenic sarcoma. When injected intraperitoneally into 

 rabbits, it induced osteogenic sarcoma at distant sites. When adminis- 

 tered intravenously, it induced, in addition to bone sarcomas, massive 



liver damage with secondary cirrho- 

 sis; whether this will be followed by 

 carcinoma has not been established. 

 Plutonium as citrate or nitrate 

 injected intratracheally or pluto- 

 nium oxide and cerium oxide pro- 

 duced as aerosols by burning, 

 inhaled by rats, caused squamous 

 and medullary carcinomas of the 

 lung (Lisco et al., 1947; Lisco and 

 Finkel, 1949). 



Strontium-89 given intraperito- 

 neally induced in mice heman- 

 gioendothelioma of the femur and, 

 more commonly, osteogenic tumors 

 in different bones. Radium, stron- 

 tium, and the rare earth and 

 transuranic elements are all "bone 

 seekers" which means that from 

 the primary sites of injection they 

 are likely to be translocated to bones. 

 Large doses of P 32 (Koletsky et 

 al., 1950), injected in rats either in 

 single or repeated doses, caused the development of osteogenic sarcomas 

 (Fig. 18-7) in many bones and squamous cell carcinomas in about 47 per 

 cent of the animals. Radiophosphorus, as well as many other fission 

 products, was deposited heavily in the skeleton. The carcinomas in 

 these rats originated in structures close to bone, as in the roof of the 

 mouth. The dose used in rats is estimated to be about twenty times the 

 usual therapeutic dose in man. When applied to the skin, the radiation 

 of P 32 caused multicentric tumors in every rat exposed (Raper et al., 1946; 

 Raper, 1947; Henshaw et al., 1947). 



Fig. 18-7. Osteogenic sarcoma in a rat 

 tibia produced by P 32 {after Koletsky et al. 

 1950). 



NEUTRONS 



Henshaw et al. (1947) studied the effect of fast neutrons from the Oak 

 Ridge reactor and noted a marked increase in the incidence of leukemia 

 and ovarian neoplasms. The incidence of leukemia following a single 



