Urinary Radioiodine Excretion at 15 Days J K day"! rT L day+ x 10° “U day x 107 2 of 13"day TE 3.7 4.85 7.2 0,050 3.7 4.35 13.8 0.066 3.7 17.15 7.2 0.16 17.15 13.8 0,21 3.7 | On the basis of these calculations the normal range of urinary radioiodine excretion at 15 days was estimated to be 0.05 to 0.2% of the peak thyroid content. The problem outlined above is a practical application of an analytical study on the uptake and excretion of iodine in man which will ve described more fully in a UCRL report entitled, "The Dynamics of Iodine in Man." ~~ ied wr me ew eee