Uptake and kinetics of /sup 226/Ra, /sup 210/Pb and /sup 210/Po in big sagebrush. [Artemisia tridentata]
Root uptake of /sup 226/Ra, /sup 210/Pb and /sup 210/Po by mature sagebrush was studied using a soil injection method for spiking the soil with minimal root disturbance. The main objective was to measure vegetation concentrations and determine concentration ratios (CR's) due to root uptake as a function of time in mature big sagebrush. Concentration ratios obtained in mature vegetation and in steady-state situations may be valuable in assessing the impact of uranium mining and milling. The vegetation was sampled approximately every 3 months for a 2 year period. Significant levels of activity were detected in the vegetation beginning at the first sampling (81 days after soil injection for /sup 226/Ra, 28 days for /sup 210/Pb and /sup 210/Po). There was an exponential decrease in concentration to an apparent steady-state value. Mean values (geometric) of the data pooled over the second year period indicated that the steady-state CR's for /sup 226/Ra, /sup 210/Pb and /sup 210/Po, as determined in mature sagebrush, were 0.04, 0.009, and 0.08, respectively. A three compartment mathematical model was formulated to help understand mechanisms of plant uptake and to predict, if possible, the concentration of /sup 226/Ra, /sup 210/Pb and /sup 210/Po in vegetation as a function of time after soil spiking. A numerical solution was determined by 'calibrating' the general model solution with constants determined from regressions of concentrations in vegetation, soil leaching and leaf leaching data. Validation of the model is currently not possible because of an absence of similar time-dependent uptake studies. 168 refs., 19 figs., 18 tabs.
- Research Organization:
- Colorado State Univ., Fort Collins (USA)
- DOE Contract Number:
- AC02-79EV10305
- OSTI ID:
- 6530104
- Report Number(s):
- DOE/EV/10305-16; ON: DE86003156
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products. Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LEAD 210
CONCENTRATION RATIO
ROOT ABSORPTION
POLONIUM 210
RADIUM 226
ARID LANDS
DOSE EQUIVALENTS
ENVIRONMENTAL EXPOSURE PATHWAY
EXPERIMENTAL DATA
GRASS
MATHEMATICAL MODELS
RADIONUCLIDE MIGRATION
REGRESSION ANALYSIS
SHRUBS
TERRESTRIAL ECOSYSTEMS
TIME DEPENDENCE
URANIUM MINES
ABSORPTION
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DATA
DAYS LIVING RADIOISOTOPES
ECOSYSTEMS
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
HEAVY NUCLEI
INFORMATION
ISOTOPES
LEAD ISOTOPES
MASS TRANSFER
MATHEMATICS
MINES
NUCLEI
NUMERICAL DATA
PLANTS
POLONIUM ISOTOPES
RADIOISOTOPES
RADIUM ISOTOPES
STATISTICS
UNDERGROUND FACILITIES
UPTAKE
YEARS LIVING RADIOISOTOPES
510302* - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- Terrestrial Ecosystems & Food Chains- (-1987)