498 TRANSURANIC ELEMENTS IN THE ENVIRONMENT 



r 



85% 



CONSTANT 

 (3 vr) 



PULMONARY* 

 LUNG (100%) 



15% VARIABLE 

 (50 days INITIALLY 

 DOUBLING EVERY 

 YEAR) 



9% 



J 



1 00% 



SUMMATION 

 OF FECES 



10% ' 



THORACIC 

 LYMPH NODES 



COMPARTMENT 



2 



(INFINITE) 



80% 



70% 



COMPARTMENT 



1 



(1 yr) 



1% 



r 



ABDOMINAL 

 LYMPH NODES 



COMPARTMENT 



2 



(INFINITE) 



70% 



COMPARTMENT 



1 



(1 yr) 



30% 



10% 



BLOOD 



30% 



1 00% 



SKELETON 

 (100 yr) 



25% 



1% 



KIDNEYS 

 (40 yr) 



2% 



99% 



SUMMATION 

 OF URINE 



2% 



90° 



LIVER 

 (40 yr) 



71% 



*BASED ON 100% OF THE INITIAL ALVEOLAR DEPOSITION. 



Fig. 6 Block diagram of the long-term form of the Stuart, Dionne, and Bair (SDB) 

 model. 



Group model. In addition, they included feedback pathways for Hver to the 

 gastrointestinal tract (GIT) and for liver, kidneys, and skeleton to blood. Since they 

 applied this model to inhalation only, they did not consider the transfer from GIT to 

 blood since the fraction transferred is so small (less than 0.0 17f). 



On the basis of Figs. 5 and 6, the equations for the compartments of the respiratory 

 tract and lymph nodes plus the transfer to GIT and blood are 



^GIT = fuRG^NPTBYNPTB + ^LCG^LCYLC + ^LVYLV + fLG^LYliver (59) 



fB - ^URB^NPTBYNPTB + fLCB-^LCYLC + ^TLB^TLYTL 



NM 



+ ^ALB^ALYALNM + fLB^'^LYHver + ^KB^KYK + ^BYbone (60) 



dYNPTB 

 dt 



(0.7) (D3 + D4 + Ds ) Am - (Xa + Xnptb) YNPTB 



(61) 



dYLC 



dt 



(0.3) (0.85) (D3 + D4 + Ds ) Am - (Xa + Xlc) Ylc 



(62) 



