| OFFICIAL USE ONLY IV. INTERNAL CONTAMINATION OF ANIMALS At the time of the fallout on Rongelap Island there were a variety of animals present. These were leftto live on the Island, and representative numbers were collected on the 8th, 25th, 33rd, and 5ist-53rd days and then sacrificed. Tables Thirty-seven, Thirty-eight, and Thirty-nine, show the relevant data concerning external doses to the animals while living on the Isiand, and an analysis of their in- ternal contamination. Over 90 percent of the activity in the body of animals was in the akeleton. At 92 days past detonation, 62 percent of the skeletal beta activity of the pige was due to er89 seven percent Ha percent rare earth group. 140 and 10 However, it was reported that "---In the six months periodpost detonation neither significant gross changes nor pathological changes which could be definitely ascribed to radiation were detected in any of the animis."© | Table Forty shows the activity of a rooster and rats collected two years post aetonation.° The gross activity in the rooster was ho percent of that of a rooster fram the same locality at one year post detonation. About 86 percent of the total body activitywas in the Bkeleton. | Since these animals represented interesting cases of living continuously in a heavily contaminated environment, an analyses was made later of some rats and a rooster collected at the two year period (Table Forty~one).” These data are obviously not complete nor precise but do indicate the relatively low body burden of Btrontium-90. ~ 5002138 e OFFICIAL USE ONLY e