Uranium and thorium isotopes in some red sea sediments

Abstract

Natural radioactivity / Uranium / Thorium / Sediments / Marine / Red seaSummary. Alpha-emitting isotopes of uranium and thorium in surface marine sediments collected from the harbours at Port Sudan and Sawakin on the Sudanese coast of the Red Sea have been studied using radiochemical separation procedures and alpha-particle spectrometry. Activity concentrations of 238 U, 235 U, 234 U, 232 Th, 230 Th and 228 Th were measured. The ranges of activities observed for 238 U and 232 Th were 2.71Ϫ13.42 Bq/ kg and 3.62Ϫ18.73 Bq/kg from Port Sudan and 3.87Ϫ 24.79 Bq/kg and 1.13Ϫ10.04 Bq/kg dry weight from Sawakin, respectively. The behaviour of these decay-series nuclides was examined using daughter/parent and non-isotopic specific activity ratios in sediments. Simple regression analysis showed insignificant correlation between uranium and thorium activities and the organic matter content in sediments. The results are compared with those from coastal waters of other oceans.

Accumulation of Natural Uranium Isotopes in Malaysian Harbour Sediment

“…Naturally occurring radionuclides present in a harbour ecosystem might come from river effluents of which their distribution is related to their back rock sediments and terrestrial origin [5,6]. In addition, the distribution and concentration levels of radionuclides in harbour also has oceanic influences i.e., authigenic uranium [7] and anthropogenic sources i.e., phosphorites or phosphatic fertilizers [8,9].…”