SLIDE 21 Radioactivity intake estimated from excreta. The fraction of an initial 13ly activity intake by ingestion that would be eliminated by an adult on a given day post the intake was calculated by two methods. One was a model by Johnson (Jo81) and the other was a model used by ICRP (ICRP79). Both models had feedback incorporated into the estimate of the fraction of initial intake. Both were solved using catenary compartment kinetics and both led to similar valyes for elimination of I by a reference man. Based on 0.48 kBa (1.32 x 10°“ wCi) in adult urine 9} the 17th day post intake, a 3,440 kBq (93mw Ci) intake was estimated for 1 . The intake of 3,440 kBq (93 &Ci) ¥aF used as a normalization point. That is, once the relationship between I and other nuclides in fallout was determined by us, then the contrt¢pution to thyroid dose from all radiolodines was estimated while keeping the I intake at 3,440 kBq (93 ACL). Whole-body retention functions were given by ICRP (ICRP72) for strontium and barium as fgllows: -5 <4 R(t) = 0.60078 +2540 ,299(¢40.20)7018(0,555¢76#5R10 tag 445e72s6R10 He . _ -4 _ 4 'E), 36x10 436074 “tg 209x190 564071 (0, (t+0.007)-0°237 540,191 0.38e97 Raat) = where t is in days and R(t) is the absorbed fraction remaining on day t. The fecal to urine ratios for excretion of absorbed Sr and Ba weg 0.25 and 9.0, respectively (ICRP72) Correcting for45 days of decay, the 125 activity absorbed was estimated to be 2.3 x 10° Bq (0.62 wCi) and the Ba activity. absorbed was 6.1 x 107 Bq (16.4 Mei). If fallout was directly ingested as a single intake of dust at 0.5 days post detonation, then the intake of 1405,, 905, or 131; should be in a ratio similar to one estimated by us by a different approach. The fraction of ingested iodine absorbed into blood was taken as 1.0, the fraction of ingested strontium absorbed into blood was taken as 0.2 and the fraction of ingested barium absorbed into blood was taken as 0.06 CICRP68} « The tpgake ratios we obtained from urine results for I relative to “Sr or Ba are 28 and 0.34, respectively. The hypothetical ratios are 8.5 and 1.2 based on unfractionated thermonuclear fission data. Thus the urine derived Ratio of activity is a factor of 3, gwer than the hypothetical ratio for Sr and a factor of 3 higher for ESTIMATE OF ACTIVITY INGESTED (RONGELAP) Activity Nuclide Ingested Bq vol 3.4X10° ‘Ba 1.0*10 Sr 1.2x10, Iodine Activity” — Nuclide Activity 1.0 8.5 1.2 “Thermonuclear neutron fission and 5 hours post detonation. 26 Ba.