METHODS DOSI tETRIC EQUATIONS Declining continuous uptake of radioactive dietary items was mathematicall modeled for each nuclide of concern. The following general equations were used ype w o X.K *iti f, (s Ce i K-KE q-q° (i Xie E | . 1 (e - Qa+Kgt Xi 1 (2 py ii : Po =() 4K, et AD) -(\+Kp)t -(A+K, de E’" -e i’) Ly! Ap? = be ERP ,L UU Ue/fu- a GRe —-OA+K.)e i) (1) » and . _ - (A+Kj)t)) (2) o£ (Kixke -(A4K;) en (AtKgit + (A+Kg) aw) Ki-K 1 E (KU+A) (K.1 +A) E ' +q° = i X. car fire -(A 4K; et i i), (3) where t = time post onset of uptake, days, . X = instantaneous fraction of atoma decaying per unit time, day! P° = initial atom ingestion rate, atoms day~!, Kj = instantaneous fraction of atoms removed from compartment i by physiological mechanisms, day~!, Xj; = compartment i deposition fraction, ‘ Xs = the number of atoms in compartment i relative to the number in all compart- ments at the onset of uptake (t=0), U = instantaneous urine activity concentration, Bg gol, U_ = subject urine excretion rate, & day~!,