90 EFFECTS OF IONIZING RADIATION fertile, 3 fertile ones were opened prematurely, 11 developed complete embryos but failed to hatch, and 23 live chicks were hatched, one of which had congenital perosis. The latter chick and six normal ones were sacrificed and their tissues radioanalyzed. Again, only barely detectable amounts of internally deposited activity were found. The remaining baby chicks are being raised and observed for possible long term effects. .At the present time all the chicks are growing normally and are in good health. Comparison of the fertility and hatchability data of Rongelap hens with those from domestic hens does not demonstrate any etfect of radiation on these phenomena. 5.47 Incernal Radioactive Scudies in Chickens Decontamination A study was undertaken to determine the ability of both sodium EDTAand zirconium citrate (15) to increase the excretion rate of internally deposited fission products in the contauminated chickens. On the basis of previous experience, i¢ was not expected that any appreciable decontamination could be effected at the time of this experiment (4 months following internal radioactive deposition). The excretion rates of 8 chickens with large bedy burdens of internal contaminants were determined for a period of 4 days as the base line for the study. Following this, two chickens were injected daily I. P. with 75 mg. sodium EDT.A for four days: two received injections of TO mg. of zirconium citrate (15). and two were injected with both zirconiumcitrate and sodium EDTA. Two chickens were kept as controls. The mean beta and gamma activity excreted by these chickens was determined individually for each of the treatment days and for 1 day following cessation of treatment: Neither the zirconium citrate nor the sodium EDTA alone was effective in increasing the excretion rate as reflected by the beta activity INensurements made. The combined administration of zirconiumcitrate and sodium EDTA, however, doubled the excretion rate of the beta activity. No detectable change in the rate of excretion of gamma activity was noted. The excretion rate of fission products at this long period post contamination wasless than 0.1 percent per 24 hours. Thus, the enhancement of the excretion rate by the combination of zirconiumcitrate and sodium EDTAdid notsignificantly decrease the total body burden. 5.48 Summary Studies of animals provided data on the nature and distribution of the radioisotopes in the tissues and the excreta. Over 90 percentof the activity in the body of animals was localized in the skeleton. The pattern of deposition of the fission products in the skeleton seen in autoradiographs resembles that of the alkaline earths. Morphological changes which were observed in some of the bones maybe theresult of the exposure of the animal to external radiation, although the effects of severe dietary changes and other disense cannot be ruled out. The alkaline earths Sr® and Ba'” and the rare earth group together constituted 75 percent of the gross beta activity in the pig at 82 days post detonation, The fish and clam had a much lower concentration of the alkaline and rare earths, and a body burden considerably higher than that of the land animals. The internal distribution of fission products in the pig is probably representative of the distribution in human beings. .\n estimate of the human body burden was derived from the data on pigs. Studies made on egg production of contaminated hens gave no evidence of any effect of radiation. The rate of production and the eggs produced were both normal. The extraordtnary ability of fowl to mobilize calciumin shell formation resulted in the presence of very high activity in the shells of the first few eggs. The activity was associated with the fission products of the alkaline earth group. A significant amount of activity was found in the yolk, and lesser amounts in the albumen. The remova of activity from the body of chickens by egg production provides an effective natural decontamination process.