|Author||van Wijk, H. F. ♦ Braams, R.|
|Source||United States Department of Energy Office of Scientific and Technical Information|
|Subject Keyword||BIOLOGY AND MEDICINE ♦ CESIUM 137 ♦ CONTAMINATION ♦ MAN ♦ PLANTS ♦ RAIN ♦ SOILS|
|Abstract||The possibility of Cs/sup 137/ uptake by man via the soil was studied by conducting transport and assimilation experiments on contaminated soil. When Csi/ sup 137/ is present on top of a compact clay layer, it remains there in spite of water precipitation, and when it is present on top of crumbled clay over a compact layer, it is washed down by water only as far as the compact layer. In sedimentation experiments, approximately 50% of Cs/sup 137/ in pH 7.5 clay was adsorbed on particles smaller than 2 mu and representing only 5% of the total clay mass. In pH 7.2 sand,>7O% of the Cs/sup 137/ was found on only 2% of the total mass. When clay and sand containing Cs/sup 137/ were shaken for 4 hr with acetate buffer, only 2 and 5%, respectively, of Cs/sup 137/ went into solution, and grass grown on clay or sand containing Cs/sup 137/ assimilated only a few tenths nths. Thoroughly washed grass held for 15 min in dilute Cs/sup 137/ solutions was found to fix approximately 30% of the Cs/sup 137/, confirming the assumption that the main route of biosphere contamination is by foliar absorption. However, soil could become an important source of Cs/sup 137/ under certain conditions, e.g., prolonged drought or low Cs/sup 137/ activity in rain water, because the cow ingests soil along with grass and its omasum has a pH of 2 to 3, low enough to dissolve approximately 20% of the Cs/sup 137/ in 1/2 hr. (D.L.C.)|
|Learning Resource Type||Article|
|Publisher Department||Physical Chemistry Inst., T.N.O., Utrecht|
|Organization||Physical Chemistry Inst., T.N.O., Utrecht|
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