D. G. BROWN 
879 
100 
90 
80 
70 
> 
1- 
60 
? 
50 
O 
40 
30 
20 
10 
0 
10 
1956-H 
I I I I I I I I I I I I 
15 20 
I I I I I I I I 
25 30 
I I I I I 
35 
I I I I I I I 
40 
IRRADIATION DAYS (lOOr/day) 
45 
Figure 2. — Mortality in 3 breeds of swine (D = Duroc, H — Hampshire, and Y — Yorkshire) exposed to whole- 
body ""Co gamma radiation in daily doses of 100 R until death. Each curve is identified by years in which 
data were obtained. 
surviving a dose of bomb radiation above 250 
rads. The major causes of death v^ere chronic 
diseases. 
A number of pathological changes were found 
in both irradiated and controls swine without 
any significant difference in frequency of oc- 
currence between the two groups. Included 
among these aberrations were the following: 
gastroenteritis, intervertebral ankyloses and 
vertebral exostoses, degenerative arthritis, 
atherosclerosis in the abdominal portion of the 
aorta, dermatitis at a few sites in older svi^ine, 
renal cysts, nephritis, pyogenic infections at 
various sites, urocystitis, cholecystitis, and en- 
dometritis. Evidently these and some other 
pathological manifestations were predominantly 
caused by trauma, infection, senility, or com- 
binations of these factors. 
Lesions attributable to effects of radiation 
were the following: asymmetrical diminution 
in the respective sizes of the musculature and 
underlying bone (Figure 5) in the pelvic region, 
usually in one pelvic limb; genital neoplasia, 
commonly manifested as leiomyomas of the 
broad ligaments and uteri ; hepatomas ; and an- 
nular, sclerosing adenocarcinomas usually pres- 
ent as stricture in the posterior one-third of the 
small intestines (Figure 6). The number of ani- 
