INTERNAL DEPOSITION OF RADIONUCLIDES but those from a given hen were of uniform weight. In 14 eggs studied, the shell and membranes weighed an average of 13.6 percent of the whole egg weight, and the ashed shell weighed 6.8 percent of the whole egg weight. These values are within the normal range for egos of domestic hens. The gross beta and gammaactivities of the shell, albumen and yolk were measured in the first 50 eges obtained, and the gammaactivity of the shel! was measured in the remainder of the eggs. An increasing amount of gamma activity appeared in the shells of the first few eggs laid by each hen. The maximum gamma activity was usually noted in about the eighth egg laid. After the activity reached a maximin Value, the subsequent eggs in the series showed a general decline in activity. Two examples of this phenomenon are illustrated in Figure 5.6. The highest gammaactivity found in a single egg shell was 66,300 counts per minute, measured at 60 days post detonation. For a gammaenergyof approximately 1 mev, this figure corresponds to 0.0Tye. The yolks andalbumens had muchless activity than the shells, as Was anticipated. The average distribution of gammaactivity in the eggs is given in Table 5.11. Theresults of the radiochemical analysis of two eggs are presented in Table 5.12. The alkaline earths are the principal fission products deposited in the shell. In the albumen and yolk, the beta activity contributed by the alkaline earths was only a little greater than that associated with the rare earths. The pattern of deposition of the radioactivity within the eg was also studied by means of autoradiographs. A series of 50 eggs were hard boiled, sectioned, and autoradiographs were prepared of the cut surfaces. Only four of the yolks of these 50 eggs were sufficiently radioactive to produce autoradiographs (see Fig. 5.7). These + eggs were laid on successive days by the same hen. There is a correlation between the rings of radioactivity in the yolk andthose of pigment. The amount of activity removed from the body of the chicken through egg laying is very Ue oi co C= owas 4 381712 O—56—_7 89 Table 5.11.—Distribution of Gamma Activity in Chicken Eggs PERCENT OF PERCENT OF Tota GaMMa! Tota. BETA ACTIVITY ACTIVITY Shells_.-._-.--..-_-_.-____Yolks_.__.__-.-_-_.___. Albumen. __.___.______- 81 15 4 | 68 23 8 Table 5.12.—Radiochemical Analysis of Chicken Eggs Beta SAMPLE Activity, D/M/ToTaL TIssvE Montus Post DETONATION Sri Egg No. 27 Yolk____Albumen-_ 355 52 Bale 546 92 Rake EARTHS 663 90 aT 4 Gross Beta ACTIVITY 1, 560 260 Shell... - 18, 080 3,520 6,060 30, 000 Yolk. ._ Albumen_ Shell_____ 315 45 22, 300 825 132 4,900 997 132 7, 830 2, 178 316 38, 000 Egg No. 29 much greater than the amount excreted in the urine and feces during the period of this study. Iigg production in the chicken represents a unique forin of natural decontamination. 5.46 Fertility and Chickens Hatchability Studies in Fertility studies on the contaminated chickens were begun 314 months post detonation, with the mating of hens and roosters and the incubation of the eggs obtained. In the first clutch of 20 eggs, 4 were hatched. One of the chicks had the crippling slipped-tendon condition, “congenital perosis,” which is not uncommon. Radioanalysis of the chick tissues ind1cated that only a barely detectable amount of radioactive material was transferred to the chick, although the mother hen had at this time an appreciable contamination. In another hatch six months post detonation, 65 eggs were incubated. Of these, 28 were in-