Radiological Risk Assessment and Radioactivity Concentration in sediment of Tigris River of the Medical City/Bab Al Muadham

Abstract

The concentrations of natural radionuclides in sediment samples from various locations along the stream of the Tigris riverbank in the Medical city in Bab Al- Muadham, Baghdad, had been examined using NaI(Tl) detector. The mean concentrations of specific activity for ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs for sediments of the river was 13.5±4.6, 35.2±3.1, 272.2±21.4 and 1.5±0.35 Bq/kg  respectively. The findings revealed  that the concentration values of natural radionuclides and cesium were below permitted limits. The radiological hazard was compared with a global average (Radium equivalent, absorbed dose rate, radiation hazard index and annual effective dose equivalent) finding it was less than reported by UNSCEAR . The radium equivalent activity was 102.22 Bq/kg and the maximum absorbed dose rate was 88.1 nGy/h. At the same time, the mean annual effective dose equivalent was 420.1 µSv/y. The highest risk index was 0.39 and is much less than 1, except for the lifetime cancer risk were valuing between 164.2×10⁻³ to 1620×10 ⁻³. This is a higher value than the global average.