ANALYSIS OF 238U, 226Ra, AND 210Pb TRANSFER FACTORS FROM SOIL TO THE LEAVES OF BROADLEAF TREE SPECIES

This analysis of U-238, Ra-226 and Pb-210 transfer factors from the soil to the leaves of different native broadleaf trees at sites previously modified by uranium pres ence and at the site of back ground radioac tivity levels, was conducted using data from a few available studies from the literature. The broadleaf tree species Quercus ilex, Quercus suber, Eucalyptus camaldulensis, Quercus pyrenaica, Quercus ilex rotundifolia, Populus sp. and Eucalyptus botryoides Sm. at the affected sites and Tilia spp. and Aesculus hippocastanum L. at the background site were included in the study regardless of the deciduous or evergreen origins of the leaves. In the papers cited here, data about basic soil parameters: pH, total Ca [ gkg(-1)], sand [%], and silt + clay [%] fractions were also available. All the collected data of activity concen tration [Bqkg(-1)] dry weight in the soil (n=14) which was in the range: 22-6606 for U-238, 38-7700 for Ra-226, and 37-7500 for 210Pb, and the tree leaves in the range: 2.7-137.6 for U-238 (n=10), 2.6-134.2 for Ra-226 (n=14), and 27-77.2 for Pb-210 (n=14), indicated that it was nor mally distributed after log-transformation. The present study was conducted under the hypothesis that biological differences between the examined broadleaf tree species have a lesser influence on the transfer factors of the investigated radionuclides from soil to tree leaves compared to the impact of the soil parameters and radionuclides activity concen trations in the soil. Consequently, it was examined whether U-238, Ra-226, and Pb-210 soil-to-leaves transfer fac tor values for average broadleaf spe cies could be predicted statistically in the first approximation based on their ac tivity concentration in the soil and at least one basic soil parameter using multiple linear re gression.