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 left to live on the Isiand, 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 Island, and an analysis of their in- ternal contamination. Over 90 percent of the activity in the body of animals was in the skeleton. At 82 days past detonation, 62 percent of the skeletal beta activity of the pigs was due to gO seven percent Ba 140 >» and 10 percent rare earth group. However, it was reported that "---In the six months period post detonation neither significant gross changes nor pathological changes which could be definitely ascribed to radiation were detected in any of the animis.” 8 Table Forty shows the activity of a rooster and rats collected . two years post detonation. 6 The gross activity in the rooster was 40 percent of that of a rooster from the same locality at one year post detonation. About 86 percent of the total body activity was in the * skeleton. 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 strontium-90. OFFICIAL USE ONLY