Health Risk Assessment and Statistical Analysis of Natural Radioactivity in the Uranium Exploration Area of Zabili, Chad

Abstract

The activity concentrations of natural radionuclides 226Ra, 232Th and 40K in nineteen soil samples from Zabili uranium exploration area were measured using a low-background digital gamma-ray spectrometer equipped with broad energy germanium detector. The activity concentrations of 238U, 232Th, and 40K range from 16.5 to 1110.9 Bq.kg− 1, 19.45 to 76.97 Bq.kg− 1, and 3.28 to 839.5Bq.kg− 1, with their mean values of 478.0, 58.9, and 562.5, respectively. In addition, radiological hazard parameters from the activity concentrations obtained were assessed by estimating radium equivalent activity, external and internal hazard index, indoor and outdoor absorbed gamma dose rate and the corresponding annual effective dose, effective dose rate to different body organs and tissues, and excess lifetime cancer risk. Derived radiological hazard indices have been revised in accordance with relevant national and international legislation and guidelines. The radiological hazard parameter values were found to be above the relevant limit values for soils. In order to investigate the distribution of radionuclides and associated health hazard parameters in the study area, a statistical study was performed.