A. Martinezaguirre et al., TRANSFER OF NATURAL RADIONUCLIDES FROM SOILS TO PLANTS IN A MARSH ENHANCED BY THE OPERATION OF NONNUCLEAR INDUSTRIES, Journal of environmental radioactivity, 35(2), 1997, pp. 149-171
Two sampling campaigns were performed in 1993 at the marsh area (Odiel
marsh) located in southwestern Spain, in the city of Huelva. Spartina
densiflora and substrate soil (5 cm deep) samples were collected in s
everal locations across the area in each campaign. Activity concentrat
ions of Po-210, U- and Th-isotopes were determined in the plant and th
e substrate samples. The production of phosphoric acid from phosphate
mineral in the vicinity clearly enhances the concentrations of these r
adionuclides in certain areas of the marsh. Moreover, concentrations i
n plants are affected by the concentration of the same element in its
substrate. Indeed, high concentration levels in plants are coincident
with high concentration in soils. However, concentration ratios (CR),
defined as the ratio between the concentration of an element in the pl
ant and of that in its substrate, are higher when substrate concentrat
ions are low, whereas low CR values are found in areas where substrate
concentrations are high. Moreover, both variables (CR and soil concen
tration) seem to be non-linearly related, at least, in the case of rad
ionuclides from the U-238 decay chain. (C) 1997 Elsevier Science Limit
ed.