516 BIOLOGICAL EFFECTS OF RADIATION 



There has been considerable interest in the effect of radioactive 

 materials introduced directly into the body. Perhaps the most complete 

 experimental work is that of Thomas and Bruner (350) who injected 

 into young rats 40 to 60 fxg. of radium chloride over 126 to 191 days. 

 This produced a marked secondary anemia and caused the death of some 

 rats. The bone marrow was aplastic except for an area of hyperplasia 

 in the central two-thirds of the shafts of the long bones. Growth was 

 retarded and there was a decrease of the calcification in the central por- 

 tion of all bones and calcification was concentrated near the joints. The 

 lymphocytes in the spleen and lymph nodes had been destroyed and there 

 seemed to be an increase in the number of lymphoblasts, plasma cells, 

 and giant cells. Extramedullary myelopoiesis was marked in the spleen 

 and lymph nodes and present to a slight extent in the liver. There was 

 degeneration of many of the cells in the adrenals. There was some non- 

 inflammatory degeneration and fibrosis of the myocardium of a few rats 

 with shrinkage of the liver. There was a parenchymatous nephritis with 

 numerous areas of calcification in the kidney. Various stages of 

 degeneration in the tubules of the testes were noted. Normal ovarian 

 folUcles were noted and the destruction of embryos was occasionally 

 found. Frequently the periosteum at the costochondral junctions was 

 involved by hyperplastic changes and often both caries and repair were 

 present. The thyroid, parathyroid, and pancreas showed no change. 

 There was recovered 99 per cent of the radium from the bone, though 

 60 per cent of this was found in the mandibles (see Martland, 212). The 

 kidneys and intestines contained the largest amounts present in soft 

 tissues. Embryos contained 3.6 per cent. The radioactive material 

 was deposited with the calcium at the knee joints and vertebrae. The 

 lungs showed a patchy pneumonia as a terminal effect but no primary 

 damage. 



Valeeff (360) studied the changes in the blood following the injection 

 of 0.5 to 1.0 mg. of thorium X intravenously in rabbits. He did not 

 think there was a direct effect of the thorium X upon the erythrocytes, 

 although there was a change in their sedimentation rate on the first and 

 second days and continuous variations in the degree of leucopenia. The 

 sedimentation rate, he believes, is apt to depend upon damage to other 

 organs, especially the bone marrow (271), although he believes the 

 capillary system is damaged, too, and there may be some effect from 

 that. The leucopenia depends upon damage of the bone marrow; the 

 lymphocytes and monocytes were thought to be slightly more resistant 

 than marrow cells (30, 49, 186, 198, 326, 350, 360, 364, 383). Barker 

 and Schlundt (17) point out the long duration with which radium chloride 

 may affect the human body when introduced into the circulation or by 

 mouth, i.e., for periods of at least 5 years (314). 



