Determination of radionuclides and elemental composition of clay soils by gamma- and X-ray spectrometry

Abstract

Radiochemical and elemental analysis of clay soils collected from different locations within Ekiti State have been performed in this study using gamma and XRF spectrometric measurements. The results of this study show that the mean concentrations of uranium ranged from 2.2 ± 1.0 mg/kg to 3.2 ± 1.1 mg/kg, that of thorium ranged from 4.0 ± 0.5 mg/kg to 5.7 ± 1.7 mg/kg, while potasium presented in % by weight ranged from 0.4 ± 0.2 to 1.3 ± 0.3 in all the locations. The overall mean concentrations of these radionuclides are comparable to values from other locations around the world. The XRF analysis revealed 4 major elements and 11 minor or trace elements present in the clay samples. The distribution of the various major and trace elements in all the sampling sites do not follow any systematic trend but vary from point to point. To assess the level of contamination and the possible anthropogenic impact in the clay soils, the enrichment factor (EF) and the geoaccumulation index (Igeo) were estimated for some potential hazardous elements. The results indicate that Cu, Zn, Ni and Mn have EF < 2 indicating minimal or no enrichment while Pb is moderately enriched in all the locations.

Leaching of Potentially Toxic Metals (PTMs) from Two Nigerian Clays and Related Clay Pottery Used Locally as Foodwares

“…The order of concentrations is Fe>Mn>Pb>Zn>Ni>Cr>Cu>Cd for Ara-Ekiti Clay, Kono-Boue Clay and the Ara-Ekiti Clay Pot (Table 2) and this order is consistent with elemental data previously published by Omoniyi [9] and Gbarakoro [3]. The mean concentrations observed in this for Ni, 77.67 ppm, Pb, 135.27 and Zn, 93.17 ppm are within the range of concentrations of Ni, 88-290 ppm, Pb, 75-310 ppm and Zn, 88-290 ppm, previously reported for Ara-Ekiti Clay deposits by Omoniyi [9]. The order of concentrations, Fe>Mn>Zn>Pb>Ni>Cr>Cu>Cd for Kono-Boue Clay Pot is different compared to that of Ara-Ekiti Clay Pot, consistent with previous EDX elemental composition count data on Kono-Boue Clay by Gbarakoro [3].…”

Evaluation of radiological risks due to natural radioactivity around Lynas Advanced Material Plant environment, Kuantan, Pahang, Malaysia

“…(Omoniyi et al 2013). According to UNSCEAR (2000) report, man spends an average of 20 % of his time outdoors, and through this period, he gets continuous exposure by gamma radiations originating from 238 U, 232 Th and 40 K in soil within the upper 30 cm of the earth surface (Al-Jundi et al 2003;Chikasawa et al 2001;Dabayneh et al 2008;Mandić et al 2010;Tzortzis et al 2004).…”

Radiological health assessment of natural radioactivity in the vicinity of Obajana cement factory, North Central Nigeria

“…This counting time was sufficient enough to produce strong peaks at gamma emitting energies used to evaluate the radionuclides considered in this study. Assuming secular equilibrium, respectively, in the uranium and thorium decay chains, 226 Ra was determined by means of its progeny photo peak, 214 Bi (1760 keV), and 232 Th was analyzed by means of its progeny photo peak, 208 Tl (2615 keV)[ 16 ] The 1460.75 keV gamma-ray transition line was used to measure the activity concentrations of 40 K.[ 17 ] The activity concentrations in the samples were calculated according to the following expression:…”