Heavy metals, radionuclides activity and mineralogy of soil samples from an artisanal gold mining site in Ile-Ife, Nigeria: implications on human and environmental health

• Published in: Environmental earth sciences 2021-03, Vol.80 (5), Article 202
• Main Authors: Ogundele, Lasun Tunde, Oluwajana, Oladotun Afolabi, Ogunyele, Abimbola Chris, Inuyomi, Samuel Oluwagbenga
• Format: Article
• Language: English
• Subjects: Atomic absorption analysis; Belts; Biogeosciences; Biotite; Cadmium; Calcium ferrous silicates; Carcinogens; Chromium; Contamination; Earth and Environmental Science; Earth Sciences; Environmental health; Environmental impact; Environmental monitoring; Environmental Science and Engineering; Gamma rays; Geochemistry; Geology; Gold; Gold mines & mining; Health risks; Heavy metals; Hydrology/Water Resources; Ilmenite; Kaolinite; Lead; Manganese; Metal concentrations; Metals; Mineral exploration; Mineralogy; Mining; Nickel; Norms; Original Article; Plagioclase; Radiation; Radiation dosage; Radiation hazards; Radiation measurement; Radiation monitoring; Radioisotopes; Radionuclide kinetics; Radium; Schist; Schists; Soil; Soil mineralogy; Soils; Spectral analysis; Spectrometry; Stainless steel; Stainless steels; Terrestrial Pollution; X-ray diffraction; Zinc
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-021-09494-w

The Ife-Ilesha schist belt of the Nigerian Basement Complex is renowned for artisanal gold mining activities owing to the occurrence of gold-bearing eluvial deposits within and around the belt. However, gold mining operations in Ile-Ijesha axis are carried out haphazardly without consideration of probable health risks that might be posed to the miners and local community by heavy metals and naturally occurring radionuclides materials (NORMs) contents in the soil. This study was therefore conducted to determine the mineralogy, heavy metals contents and radionuclide activity of soil samples collected from a gold mining site in Ile-Ife with a view to assessing the consequential health and radiological risks. Thirty-five (35) soil samples were collected from abandoned and active excavating pits over the entire area using stainless-steel spade. The heavy metals and radionuclides concentrations and mineralogical compositions of the samples were obtained by Atomic Absorption Spectroscopic (AAS), gamma ray spectrometry and X-ray diffraction (XRD) methods, respectively. The contamination indices consisting of Enrichment Factor (EF) and Index of geoaccumulation ( I geo ) were calculated from heavy metals concentrations. The sequence of the average concentrations of heavy metals in the soil samples decreases as follows: Pb (72.93 ± 4.60) > Cd (58.26 ± 3.25) > Cr (42.81 ± 3.00) > Zn (33.66 ± 2.71) > Mn (24.60 ± 1.80) > Ni (23.93 ± 2.51). The mean EF values of the measured heavy metals occurred in the order of Cr > Pb > Zn > Cd > Ni. The I geo values of the measured heavy metals (except Pb) were less than one (