Environmental monitoring for some transuranium elements

Methods used for the analysis of environmental materials for transuranium elements were described and the results were given. The plutonium concentration in air varied with time in the same manner as other stratospheric fallout nuclides, but also depended in part on the amount of soil in the air. The resuspension factor for plutonium was about 3x10-10/m, if the air concentration is corrected for the fallout contribution, but about 100 times greater if calculated from the total airborne concentrations. Resuspension factors for thorium and uranium were about 1x10-10/m. Average 239Pu, 240Pu concentrations in soil were about 2.4 nCi/m2 (4-10 fCi/g) in the top 30 cm of soil. The 238Pu concentrations were 10 to 20 times lower. The plutonium content of grass, in terms of deposition, was about a factor of 104 less than in soil. Plutonium deposition from precipitation averaged about 1 pCi/m2/month from 1972 through 1975. The 239Pu, 240Pu content of surface water ranged from 0.2 to 0.5 fCi/l. The concentration was relatively independent of the size of the body of water, and may represent the solubility of fallout plutonium in natural water systems. Normal concentrations of other transuranium nuclides were less than 0.5 fCi/l. The plutonium content of bottom material from lakes and streams was quite variable, although generally less than in surface soil. An important parameter was the retentiveness of the bottom material. Since the benthos can accumulate plutonium over a period of time, it is a more sensitive indicator of plutonium contamination than the overlying w