FALLOUT NUCLIDE SOLUBILITY, FOLIAGE CONTAMINATION, AND PLANT PART UPTAKE CONTOUR RATIOS
Mathematical formulations for fallout nuclide solubility, foliage contamination, and plant part uptake contour ratios are presented for estimating the degree to which various radionuclides in fallout enter the food chains. The nuclide solubility is determined, for the fallout from a landsurface detonation, mainly by the properties of the soil carrier material at the point of detonation and other conditions of detonation. The major parameters which determine foliage contamination are the size of the deposited particles, the foliage surface density, and the fallout deposit level. The type of leaf surface and its orientation are also factors, but the available data are not adequate to resolve the effect of these two factors on the direct contamination of foliage. Very few data are available on the change in foliar contamination with plant size or age for amimal crops. The plant part uptake occurs by both foliar assimilation or absorption and assimilation through plant roots (for fallout mixed in the soil). Data on foliar assimilation from solid particles deposited on plant foliage and fruits have not been reported. The reported data are from contamination by liquid sprays in laboratory experiments and, indirectly, from world-wide fallout that is deposited mainly in the form of rain drops. Essentially no data are available for making quantitative estimates of food crop contamination by foliar absorption for nuclides in fallout from land-surface detonations. Leaching by rain or washing, the degree of movement of nuclides through the plant, and various plant characteristics are factors which influence the degree of contamination of edible plant parts. The major parameters for uptake in plant parts from the soil are the soluble and available nuclide concentrations in the soil, the plant part surface density, the distribution among the different plant parts, and the type of soil. From the available data, the radioelement having the highest soil uptake contamination factor is Sr/sup 90/, the highest values found for the factor are generally for plant leaves and the lowest values are usually for grains or seeds and fruits. (auth)
- Research Organization:
- Stanford Research Inst., Menlo Park, Calif.
- NSA Number:
- NSA-17-038732
- OSTI ID:
- 4634760
- Report Number(s):
- NP-13115
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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