PLUTONIUM CONTENTS OF FIELD CROPS 39 7 



composition of the resuspendible portion to approach that of the soil values. After the 

 initial cultivation, the ^^^Pu percentage for the resuspendible matter decreased from an 

 average of 50 to an average of 27 for the two fields. 



Soils at woe Floodplain, Oak Ridge 



Concentrations of plutonium in the floodplain soil generally ranged from 10 to 150 pCi/g 

 (dry weiglit) over a 3-ha area (Fig. 3). The highest concentrations occurred behind the 

 former dike, along WOC, and at the upper end of the floodplain. Concentrations of 

 plutonium were less than 25 pCi/g near the margins of the floodplain. The ^'^^Pu 

 concentration of soil at a garden plot site (W35, S295) was 63 ±0.4 (standard error) 

 pCi/g. 



A typical profile distribution of plutonium showed that the highest concentration of 

 plutonium was observed in the uppermost zone of the profile (Duguid, 1975). 

 Occasionally, however, where higher concentrations of plutonium occurred in the subsoil. 



WHITE 



OAK 



CREEK 



S30 



S60 



S90 



150 pCi/g 

 100 pCi/g 

 ^S 25 pCi/g 

 I. \ 10 pCi/g 



Fig. 3 Areal distribution of plutonium at the contaminated Oak Ridge WOC floodplain. 

 Grid size is 30 m by 30 m (900 m' ). 



