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Small white pine (Pinus strobus) and red oak (Quercus rubra) trees were contaminated in the field without a fallout simulant consisting of 88-175 ..mu.. dia. quartz particles containing /sup 134/Cs. Whole plants were harvested at intervals up to 33 days after application of the simulant, and the /sup 134/Cs retention by each species was determined. The initial fraction of the simulant retained by foliage was higher in the oaks (0.35) than in the pines (0.24). However, after 1 hr, the broad leaved oaks had lost 90.5% of the initial /sup 134/Cs concentrations while the pines had lost only about 10%. These early retention differences are related to the effects of wind on the two distinct foliage types. Effective half-lives were calculated for both species at intervals of 0.1 day, 1-7 days and 7-33 days. For pine trees these values were 0.25, 4.53 and 20.66 days, respectively. For oaks they were 0.12, 1.41 and 24.86 days. Loss of particles (/sup 134/Cs) was due, primarily, to the weathering action of wind and rain during the study. The effects of wind and the first rain following contamination accounted for a large percentage of the total radionuclide loss during the study. 10 references, 2more » figures, 2 tables.« less |
