no . There ile S@re 2. dence a; te om co \~ ‘ flat ee Nw ere - TURE: yo. o, ~ ijl, othercid trersdlaticn from I 13 OMriy Lelf as effect ..-: as x-.rraduateocn (2 orcdve nz thyroid cancer in rats, but it {$8 unkncun whether this relatien also applies tc the human infant. Tie credicned numbers or teyrcic cancers in Utah children are tabulated in Table 5 I_r beth a relative biolcgical effectiveness (™.B.E.} ef Ll and a R.D.E. of 3.1. These values are compared with the number of “spontaneous” cases exvected by aze 15 years. Children are arranged by age recognizing that some children were irradiated at age 0-1 and again at age 1-2. rarily Irradiation received at age 2 and older has been assumed arbit- (aithough pernaps incorrectly) to be without effect. Table 6 AGE IN 1963 13 12 Ll* io* 9 8 7 6 5 y 3 2 1 0 PREDICTED THYROID CANCERS IN UTAH CHILDREN NUMBER OF EST. AV. TH. PRED. TH. CANCERS CHILDREN DOSE (RADS) RBE = | RBE = 0.1 20,000 0.4 “?).16 0.02 20,000 4.2 1.68 0.17 21,000 10.1 4.24 0.42 21,000 6.3 2.64 0.26 22,000 2.0 0.88 0.09 22,000 2.0 0.88 0.09 23,000 8.6 3.96 0.40 24,900 10.0 4.80 0.48 24,000 1.4 0.67 0.07 25,000 0 0 0 25,000 oO 0 0 26,000 1.0 0.52 0.05 ar= 2) 0.52 0.05 “ Q 0 0 0.95 0.10 6.4 21.90 : "SPON." 9.4g" 0.44 0.47 0.47 0.49 0.49 0.51 0.53 0.53 0.55 0.55 0.58 0.60 0.60 0.02 2.20 5.57 foal’ mumber of fallout-induced thyroid cancers is 22 (for an R.B.E. of 1) or 2 (for an R.B.E. of 0.1). These would be in add- ition to the 6 "spontaneous" cases expected to develop in this 1/4 million children during their first 15 years. The large number of irrediated children provides a rare opportunity to test the hypothesis that small