| Abstrakt: |
A whole-body counter was used to measure 137Cs retention after oral and intravenous administration to cattle, and after intravenous administration to sheep and swine. Retention, by all three species, was described as a multi-component exponential function of time. After oral administration, cattle excreted 137Cs by a 3-component exponential pattern having half lives (T1/2) of 0.6, 4.2 and 33 days accounting for fractions of 0.22, 0.41 and 0.37 of the dose, respectively. Retention parameters for intravenous administration were similar, except that a greater fraction of the dose was excreted by the short-term component and lesser fractions by the long-term components. Excretion was slower in the case of a cow that was in late gestation. Excretion by calves was more rapid than by mature cattle. Sheep also excreted intravenously administered 137Cs with a 3-component pattern, whereas the retention curve of pigs had only 2 components. Component half lives for sheep were 1.1, 5.3 and 25.5 days, accounting for 0.26, 0.34 and 0.41 of the dose, respectively. Half lives of the 2 components for pigs were 3.5 and 34.7 days, accounting for 0.18 and 0.82 of the dose. |
