_ ree bebee ae fat ES ene oan ar Snead aietame 6 mem FL ei oy eee: * amen Appendix 9 (continued) C. Data on Principle Isotopes of Iodine Contributing to Thyroid Dose (From "Inhalation of Radfotodine from Fallout: Hazards and Countermeasures" by R. Cole 7) . Mey max’ ’ Relative abundance, & Range in tissue, um 50%-Dose Tadius," tm lodine-131 Betas 5.246 0.332 0.606 0.807 2.2 10.6 1,006 86.4 0.8 150 2,100 310 2,500 3,900 §,400 8,400 11,900 375 625 920 1,500 2,400 6,800 1,200 8,100 15,800 1,460 3,300 1,300 4,300 195 699 Todine-132 Betas 0.681 0.934 1.150 1.583 2.111 1) 20 22 22 21 Todine-133 Betas 0.49 1.34 7 93 Todine-134 Betas 0.87 1.55 2.65 3.51 5 65 25 5 Todine-135 Betas 0.40 1.00 1.43 35 40 25 7,300 1,300 *The 50%-dose radius is defined, for a point scurce in tissue, as the distance within which 50% of che dose, for that energy, is distributed. **Since this isotope with 53-min half-life igs important only for aboue 6 hr, it was not considered in the Marshallese thyroid dose calculations. - 117 -