Assessment of Soil Degradation in Areas Affected by Artisanal Gold Mining in Zamfara State, North West Nigeria

This study assesses the degree of soil degradation in areas affected by artisanal gold mining activities in Zamfara State, located in Nigeria's North West geopolitical zone. Artisanal and small-scale gold mining in Zamfara has accelerated significantly since 2010, generating widespread concerns about land degradation, heavy metal pollution, and loss of agricultural productivity in one of Nigeria's most food-insecure states. Using a descriptive survey design, surface soil samples (0 to 15 cm) were collected from active mining sites, post-mining abandoned land, reclaimed farmland adjacent to mining zones, and control farmland with no mining history across three local government areas. Samples were analysed for pH, organic carbon, total nitrogen, texture, heavy metals (Pb, As, Cd, Hg, Au trace), and total petroleum hydrocarbons. Visual land degradation assessment was conducted using a standardised scoring protocol. Findings revealed that soils at active mining sites had lead concentrations up to 2,840 mg/kg and arsenic up to 680 mg/kg, levels associated with documented childhood lead poisoning in the region. Organic carbon and nitrogen were negligible in mined soils due to topsoil removal. Reclaimed farmland adjacent to mining zones showed elevated heavy metal residues, indicating contamination plume spread beyond immediate mining footprints. The study recommends mandatory land reclamation bonding for mining operators, phytoremediation using hyperaccumulator species, and long-term monitoring of heavy metal levels in farmland adjacent to artisanal mining sites in Zamfara State. Keywords: artisanal mining, soil degradation, heavy metals, Zamfara State, lead contamination.