SREL Reprint #2923

Foliar uptake of cesium from the water column by aquatic macrophytes

J. E. Pinder III1, T. G. Hinton1, and F. W. Whicker2

1Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29801, USA
2Department of Environmental and Radiological Health Sciences, Colorado State University,
Fort Collins, CO 80523-1618, USA

Abstract: The probable occurrence and rate of foliar absorption of stable cesium (133Cs) from the water column by aquatic macrophyte species was analyzed following the addition of 133Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (103 Lkg-1 d-1) and a loss rate parameter k (d-1) were estimated for each species using time series of 133Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the 133Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u > 0.75 x 103 L kg-1 d-1. Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for 137Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases.

Keywords: Cesium; Macrophytes; Foliar uptake; Water column; Lake models; Brasenia schreberi; Myriophyllum spicatum; Nymphaea odorata; Typha latifolia; Utricularia inflata

SREL Reprint #2923

Pinder III, J. E. , T. G. Hinton, and F. W. Whicker. 2005. Foliar uptake of cesium from the water column by aquatic macrophytes. Journal of Environmental Radioactivity 85(1): 23-47.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).