Determination of thorium, uranium and potassium elemental concentrations in surface soils in Cyprus

Abstract

A comprehensive study was conducted to determine thorium, uranium and potassium elemental concentrations in surface soils throughout the accessible area of Cyprus using high-resolution γ−ray spectrometry. A total of 115 soil samples was collected from all over the bedrock surface of the island based on the different lithological units of the study area. The soil samples were air-dried, sieved through a fine mesh, sealed in 1000-mL plastic Marinelli beakers, and measured in the laboratory in terms of their gamma radioactivity for a counting time of 18 hours each. From the measured γ−ray spectra, elemental concentrations were determined for thorium (range from 2.5×10 −3 to 9.8 µg g −1 ), uranium (from 8.1×10 −4 to 3.2 µg g −1 ) and potassium (from 1.3×10 −4 to 1.9 %). The arithmetic mean values (A.M. ± S.D.) calculated from all samples are:(1.2 ± 1.7) µg g −1 , (0.6 ± 0.7) µg g −1 , and (0.4 ± 0.3) %, for thorium, uranium and potassium, respectively, which are by a factor of three to six lower than the world average values of 7.4 µg g −1 (Th), 2.8 µg g −1 (U) and 1.3 % (K) derived from all data available worldwide. The best-fitting relation between the concentrations of Th and K * Corresponding author. E-mail address: tsertos@ucy.ac.cy, Fax: +357-22892821. 2versus U, and also of K versus Th, is essentially of linear type with a correlation coefficient of 0.93, 0.84, and 0.90, respectively. The Th/U, K/U, and K/Th ratios (slopes) extracted are equal to 2.0, 2.8×10 3 , and 1.4×10 3 , respectively.

Indoor and outdoor in situ high-resolution gamma radiation measurements in urban areas of Cyprus

“…In The present results on the outdoor specific activity of the three naturally occurring radionuclides are in very good agreement with the corresponding values obtained previously by laboratory high-resolution gamma spectrometry of soil samples from the main geological formations of Cyprus (3,4) . The 5 districts covered by the present in situ measurements belong to 4 different geological formations of sedimentary origin, which have been studied and discussed in details (with respect to naturally occurring radioactivity) elsewhere (3,4) .…”

Investigation of Natural Radioactivity of Surface Soil Samples in the Vicinity of Edirne-Turkey

“…Natural radioactivity levels depend on geological aspects, mainly on rocks and soil [1,2]. Natural radionuclides in the soil are responsible for the background radiation exposure of the population.…”

Determination of Uranium and Thorium in the Industrial Phosphoric Acid Using X-Ray Fluorescence Spectrometry with Wavelength Dispersive (WDXRF)

“…-The high resolution gamma spectrometry is used to determine the concentration of uranium and thorium in the surface soils, where soil samples are ground and sieved then stored for four weeks before analysis, it is carried for 18 hours (Tzortzis and Tsertos, 2004). …”