MODEL FOR ESTIMATING Pii TRANSPORT AND DOSE 463 



may lead to far different conclusions. Or, to put the matter more bluntly, the present 

 state of the transport- and dose-modeling art is such that, by careful selection of 

 published parameter values and model equations, one could obtain a preselected result. 

 We have made every effort to avoid doing this, but we feel obliged to offer this comment 

 to warn the reader that such efforts are necessary. 



Soil 



Plutonium Concentration in Soil. Various soil surveys have been conducted to delineate 

 highly contaminated areas at NTS, to determine the horizontal and vertical distribution 

 of plutonium in contaminated soils, and for various other purposes (see several papers in 

 reports by Dunaway and White, 1974; White and Dunaway, 1975; 1976; 1977). 

 Inventories of 239,240p^ -^^ ^l^g surface soils (0- to 5-cm depth) of NAEG study areas 

 were reported by Gilbert et al. (1975, p. 379) and revised by Gilbert (1977, p. 425). 



As mentioned earlier, soil is the principal reservoir for plutonium at NTS, and soil 

 concentration (picocuries per gram) is the factor that drives or forces the transport 

 system. In developing equations to estimate potential plutonium inhalation and ingestion 

 rates for the hypothetical Standard Man, we shall attempt to relate the concentrations in 

 air and foods to the average concentration in soil. Soil concentrations based on data 

 provided by Gilbert et al. (1975) are given in Table 1. The estimated inventories (as 

 revised) are given in Table 2. 



TABLE 1 Average Concentrations of ^ ^ ^ '^ "* ° Pu in Surface Soils 

 (0- to 5-cm Depth) of NAEG Study Areas* 



*Bascd on data from Gilbert et al. (1975, pp. 393-395). 



jMean ± standard error (SE). SE = s/(n) '2, where n is the number of samples. 



