Paper Title
Uranium-Thorium Concentration In River Water A Case Study Of Pahang State Malaysia

Investigations were conducted to determine the radionuclide uranium-thorium concentration levels in the major rivers in Pahang state, Malaysia. Since the rivers are the main sources for water supply in the state, it is important to measure the uranium-thorium concentrations in the rivers in the effort to limit radiation exposures to members of the public. Seventeen water samples were collected from major rivers in Pahang state. The concentrations of uranium-thorium were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). The samples were found to contain permissible levels of the radionuclides with a mean activity concentrations of 8.49 � 0.34 mBq L-1 and 1.74 � 0.27 mBq L-1 for uranium and thorium respectively. The ratio between thorium and uranium concentration is found to be 3:4 due to the higher solubility of uranium than thorium in water. Radionuclide concentrations obtained were compared with the terrestrial gamma radiation dose rate measured around the area. Keywords- river water; uranium-thorium concentrations; activity concentrations