Heavy Metal Contamination in Soil and Sustainability Risks in Artisanal Mining Areas: A Case Study of Mayo-Sinna, Sardauna Local Government Area, Taraba State, Nigeria

Artisanal mining (ASM) is increasingly recognized as a critical source of environmental degradation and public health risk in sub-Saharan Africa. This study evaluates the concentration and distribution of heavy metals in soil samples collected from ASM sites in Mayo-Sinna, Sardauna Local Government Area (LGA), Taraba State, Nigeria. A total of nine heavy metals including cadmium (Cd), lead (Pb), cobalt (Co), copper (Cu), chromium (Cr), zinc (Zn), nickel (Ni), manganese (Mn), and iron (Fe) were quantified using standard laboratory protocols at both mining and control sites. The results reveal significantly elevated levels of Pb (0.1085 ppm) and Fe (1.4060 ppm) in mining soils, exceeding WHO (2017) and NSDWQ (2007) thresholds by approximately 985% and 368%, respectively. Manganese concentrations also surpassed safety limits by 21.5%, raising concern over long-term neurological impacts. While Cd and Co exhibited anomalous Below Detection Limit (BDL) values likely due to instrumental detection limits, control site measurements for both metals approached or exceeded international safety thresholds. Zinc and nickel levels, though within permissible limits, suggest potential for bioaccumulation and ecological toxicity. These findings provide compelling evidence of anthropogenic contamination associated with unregulated ASM activities and underscore the urgent need for regulatory enforcement, environmental monitoring, and targeted remediation strategies.