Assessment of potentially harmful elements in mine spoils of Jos and environs, central Nigeria

One of the main human activities that has greatly deteriorated the environment and people's health is mining. This study aimed to determine the level of potential harmful element contamination in mine spoils collected from Jos, Central Nigeria. Forty-five samples were collected, air-dried, pulverized, and sieved to collect fine particles and analyzed for As, Ba, Co, Cr, Cu, Mo, Mn, Ni, Pb, Sb, Th, U, V, and Zn using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The average concentrations of the potentially harmful elements in the spoils were; As: 5.70 ppm; Ba: 97.31 ppm; Be: 3.02 ppm; Co: 7.48 ppm; Cr: 124.64 ppm; Cu: 19.16 ppm; Mo: 6.19 ppm; Mn: 165 ppm; Ni: 28.84 ppm; Pb: 38.72 ppm; Sb: 0.51 ppm; Th: 36.17 ppm; U: 10.94 ppm; V: 119.84; Zn: 19.15 ppm. Pollution indices such as contamination factor (CF), pollution load index (PLI) and index of geo-accumulation (Igeo) were used to determine the level of contamination in the samples. The CF values show that the soils are considerably contaminated with As, Ba, Be, Co, Cr, Cu, Mo, Mn, Ni, Pb, Sb, V, and Zn while it is highly contaminated with Th and U. Conversely, the PLI of 0.439 shows that the site is unpolluted. Based on the index of geo-accumulation, the mine spoils are moderately- uncontaminated with As, Ba, Be, Co, Cr, Cu, Mo, Mn, Ni, Pb, Sb, Th, U, V, and Zn. Most of these elements are sourced from natural or geogenic sources, and some are remobilized from mining activities.