Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK
Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK
Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK
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3 is equivalent to assume a value for a certa<strong>in</strong> transfer rate with<strong>in</strong> the <strong>in</strong>terval of the 1 st - 99 th<br />
percentile.<br />
The transfer rates of the respiratory tract model were varied on the basis of the factor<br />
suggested by the ICRP 66 [57]. Values relat<strong>in</strong>g to the extremes of the accepted range of<br />
variation were assumed. However a decrease of the transfer rates describ<strong>in</strong>g the clearance of<br />
<strong>Plutonium</strong> from the alveolar-<strong>in</strong>terstitial compartments would have modified not only the<br />
ur<strong>in</strong>ary excretion of <strong>Plutonium</strong> (determ<strong>in</strong><strong>in</strong>g the observed enhancement), but also the lung<br />
retention of Americium from <strong>Plutonium</strong> decay. In the previous paragraph a good fitt<strong>in</strong>g was<br />
already achieved for this group of measurements. Therefore the s t parameter for Americium<br />
<strong>in</strong>growth (previously set to 0.001 d -1 just on the basis of the 241 Am lung burden measurements)<br />
was re-evaluated <strong>in</strong> order that the decrease of the <strong>Plutonium</strong> clearance rates from the alveolar<br />
<strong>in</strong>terstitial did not significantly change the achieved good fitt<strong>in</strong>g of the measurements for the<br />
lung burden of Americium.<br />
It turned out 0.0025 d -1 as best value of the absorption parameter s t for Americium<br />
<strong>in</strong>growth if the long term measurements for <strong>Plutonium</strong> ur<strong>in</strong>ary excretion, characterized by the<br />
observed enhancement, are also considered.<br />
Daily ur<strong>in</strong>ary excretion [Bqd -1 ]<br />
The calculated ur<strong>in</strong>ary excretion of <strong>Plutonium</strong> is presented <strong>in</strong> Figure 3.2.10.<br />
1E+0<br />
1E-1<br />
1E-2<br />
1E-3<br />
1E-4<br />
Measurements for 239Pu+240Pu<br />
239Pu+240Pu Ur<strong>in</strong>e<br />
Measurements for for 238Pu<br />
Pu38 Ur<strong>in</strong>e<br />
238 Pu<br />
Model predictions for 238 Measurements for<br />
Pu<br />
239 Pu+ 240 Pu<br />
Model predictions for 239 Pu+ 240 Pu<br />
1 10 100 1000 10000 100000<br />
Days post <strong>in</strong>take<br />
Figure 3.2.10 Measurements and model predictions for Americium activity excreted <strong>in</strong> ur<strong>in</strong>e<br />
us<strong>in</strong>g <strong>in</strong>dividual parameters for the <strong>in</strong>vestigated subjects.<br />
The relat<strong>in</strong>g model’s predictions for lung burden of Americium are presented <strong>in</strong> Figure<br />
3.2.11.<br />
150