Detection of Radioactive Element Contents and their Hazard indices in Composite Soil and Rock Samples from the Southern Al Jabal al Akhdar Region (Between Aslunta and Al Makhili), Libya

Abstract

The current study aims to reveal the contents of radioactive elements in soil and rock samples collected from the southern area of the Green Mountain, extending between Al-Salanta and Al-Makhili. Soil samples were taken from 20 areas, and the experimental design was a completely randomized block design with three replications. The most important results obtained are as follows: The results of this study showed the presence of several natural radioactive elements with various uses, which can be considered important natural resources. The presence of radioactive potassium (40K), uranium (238U), thorium (232Th), and radium (226Ra) were recorded, and these are natural radioactive elements that can be found in many soils. The results of this study recorded radioactive potassium concentrations ranging between (63.65– 403.56 Bq/kg), with the highest concentration found at site number 11, known as the (Al-Qarrah Al-Hamra area near the Tanmalo region), while the lowest concentration was at site 13, known as the (Tanmalo area). Regarding the results related to radioactive uranium 238, this study recorded concentrations ranging between (38.34–82.66 Bq/kg), with the highest concentrations found at site number (2), in the area of Wadi A'teer near the Aslanta area, while the lowest concentrations were at site number (9), in the area of Qlay'at near the Crushers area. Generally, the study results recorded highly significant changes at the level of 0.0001. The results related to radioactive radium showed that its concentrations ranged between (32.005–96.48 Bq/kg), with the highest concentrations found at site number (2), in the area of Wadi A'teer near the Aslinta area, while the lowest concentrations were at site number (9), in the area of Qlay'at near the quarries. Generally, the study results recorded highly significant changes at the level of 0.0001. Regarding the results related to radioactive thorium-232, this study recorded concentrations ranging between (31.15-63.18 Bq/kg), with the highest concentrations found at site number (6), in the area of (Mas'ada near Jirdas), while the lowest concentrations were at site number (20), in the area of (North Gate 1 near Al-Mukhayli). In general, the study results showed highly significant changes at the level of 0.0001. The study results recorded a clear variation in the concentrations of natural radioactive elements in the study areas. The results showed the presence of natural radioactive elements in all soils of the study sites. The following figures illustrate the distribution of radioactive elements in the study areas. When comparing the recorded results of the current study with others in different parts of the world, we find that the potassium concentration rate recorded an increase compared to the other radioactive elements in the study area, but was lower than the global average value. Additionally, the activity concentration rates of radium and thorium were lower than the global average value.