Uptake of radiocesium from contaminated floodplain sediments by herbaceous plants

Levels of radiocesium contamination in Sagittaria latifolia Willd. and Polygonum punctatum Ell., two herbaceous plant species sampled from Steel Creek on the AEC Savannah River Plant, are not correlated with total radiocesium concentrations in the soils upon which they were growing. Soils showed a bimodal distribution of radiocesium contamination and were thus divided into low level and high level classes. With only one exception, plants from high and low level soils did not demonstrate significant differences in radiocesium contaminations. Concentration of radiocesium in leaves of Sagittaria latifolia was higher in plants growing on low level soils than on high level soils. Significant correlations were observed between radiocesium levels in component parts of the same plants; however, highest correlations occurred between similar components of near-neighbor plants of the same species. Uptake of radiocesium by these two species appears to be related to factors other than the total soil concentration of the isotope.