WE The calculations are based on the only availa. le axperimental data: a) the camcentrations of activity measured in the thyroids same weeks after the fall-outs, and b) the dose rates in air as measured in the fall-out areas at ths time the fall-outs occurred. The mly additimal assumptions are: a) that the fissio sroauct mixture contained the same relative proportions of several radioactive nuclides as are calcalated by Hunter and Ballou (3), and b) that the animals ate 2CO0O gm dry vegetation per day and remaincd in a fall-out arca for about 30 days. (Tha latter assumption e-n bo relaxed sauewhat and shorter exposure times be assumed; it can still bs sham that the given thyrcid activities imply high concentraticns of activity in the bone ovur a considerable period). In addition tc the bme marrow acti-ity calculations, rouzh estimates are made of a) the total dose tc the intestinal wall fra@ the fission products as a whole which pass throu:ii, and b) local axtornal beta doses fronfission proljucts clin;ing tc the body surface. In casputing the doses, the figures for thyroid activity aud dose rates on the round ziven in reference (1) are used. Comparable *i-sures ar: later given for the sazoles massur:d in this laboratory, whien nad lower activities throughout. © nes thess latter snimais showed dziinite pathology, the hisher activities :iven in refer nee (1) sncuic al-_ost certainly indicata similar effects in those animals, The dosu tc the thyrcid for the Shot 9 case, where the final tir~ roid activity was measur:d m 3 July, will first be recalculated, using the Hunter - Ballou «> gression for the activity ar zi31, 2 Rie ‘ 2 noe ARCHIVES