TRANS URANIC ELEMENTS IN ARCTIC TUNDRA ECOSYSTEMS 44 7 



Radionuclide Concentrations in Soils 



Soil samples o\^ the Thule region during 1974 contained an average of 13.0 ± 6.3 (SE) fCi 

 (10' '^ Ci) of 2 3 9,240pu pgj. gj.gj^ I'^jj.y v^eiglit) in those areas considered to be 

 uncontaminated by the January 1968 accident debris (Table 2). The 239,240p^ 

 inventory was estimated to be 0.35 ±0.10 nCi/m^ from these samples. Two sampling 

 locations (numbers 7 and 13 in Fig. 2) within an area of about 16 km'^ near the small 

 habitation of Narssarssuk contained 20 to 100 times that inventory, which reflects 

 contamination from the accident. Alluvium samples from seasonal streambeds that 

 drained snowmelt from the landscapes across which the soil transects were taken 

 corroborated the soil measurements. The nature of the variability in aliquots taken from 

 replicate soil samples from the Narssarssuk area indicated that small particles of 

 indetenninate size contributed most of the radioactivity. Plutonium oxide particles with a 

 calculated mass median diameter of 4 jum were determined by nuclear track auto- 



TABLE 2 ^^^'^^°Pu Concentrations in Replicate 100-g 



Aliquots* of Soil and Alluvium Samples of the Thule, 



Greenland, Environs During August 1974 



*Aliquot values above the dashed lines are considered to be contaminated by 

 the 1968 accident debris. 

 T Refer to liij. 2. 



