Ecological risk assessment of soil samples from Sudanese gold-mining regions using neutron activation analysis

Abstract

This study sought to assess the concentrations of major and trace elements in soil samples taken from gold-mining sites in Sudan, with the ultimate aim being to explore the degree of pollution and risk caused by trace metals in this region. The concentrations of major elements (Al, Fe, Ca, Na, Ti, K, Mn, Ba) and trace elements (Cr, V, Zn, Rb, Co, Sc, Hf, Th, Br, As, U, Cs, Ta, and Au) were established using neutron activation analysis (NAA), while the concentrations of Cu and Ni were determined using atomic absorption spectroscopy (AAS). This revealed the presence of various major and trace elements in the samples, with some elements showing a moderate level of enrichment in certain locations. Overall, the samples were found to be unpolluted to slightly polluted, except for one sample that showed a slight-to-moderate level of contamination for certain elements. The geo-accumulation index, contamination factor, and multi-element indexes were used to assess the degree of contamination, while the potential ecological risk index was used to evaluate an ecological risk assessment. Pollution indicators showed that the soils considered in the study are at most slightly to moderately polluted by major and trace elements. This study therefore contributes to our understanding of the presence of major and trace elements, the degree of contamination, and the ecological risk presented by trace metals in the soil of gold-mining areas.