Radiological Hazards Assessment of Radionuclides in Sediment Samples of Tigris River in Mosul city, Iraq

This study was conducted in order to measure the levels of natural radiation in sediments of the Tigris River in the city of Mosul, in northern Iraq, using the gamma spectroscopy technique to calculate the activity concentrations of natural radionuclides in the sediments, The results showed that the activity concentrations of Ra-226, Th-232, and K-40. ranged between (6.30 +/- 0.319-13.73 +/- 0.411) Bq/kg and an average(9.86 +/- 0.385) Bq/kg for Ra-226, and between (13.39 +/- 0.626-29.84 +/- 0.923) Bq/kg and an average of (23.05 +/- 0.838) Bq/kg for Th-232, while potassium-40 ranged between (166.83 +/- 6.456-275.96 +/- 7.601) Bq/kg and with an average (232.91 +/- 6.456) Bq/kg All the results of these activity concentration values were less than the internationally recommended values. Using the activity concentrations of these radionuclides, radiological hazard indices were evaluated in order to determine the effects of the sediments. The calculated average value of radium-226, thorium-232 and potassium-40 are 9.86, 23.05 and 232.91 Bq/kg , respectively. The radium equivalent activity (Ra-eq), absorbed dose rate (D-gamma) , annual effective dose rate(AEDE) , internal and external radiation hazard indices (H) and Gamma Radiation Level Index (I-gamma) were calculated to study their hazardous nature. These values obtained from the sediments were less than the recommended safe and criterion limits given by UNSCEAR. Results of the present study could serve as an important baseline radiometric data for future epidemiological studies and monitoring initiatives in the study area.