Assessment of Heavy Metal Contamination in Soils Around Artisanal Gold Mining Sites in Zamfara State, North West Nigeria

Artisanal gold mining in Zamfara State has expanded rapidly over the past decade, raising serious concerns about heavy metal pollution in surrounding agricultural soils. This study assessed the concentrations of lead, mercury, cadmium, and arsenic in soils collected from mining sites and adjacent farmlands in three local government areas of Zamfara State. Soil samples were collected at varying distances from active mining pits and analysed using atomic absorption spectrophotometry. Results were compared against Nigerian Environmental Standards and Regulations Enforcement Agency (NESREA) permissible limits. Findings revealed significantly elevated concentrations of lead and mercury in soils within 500 metres of active mining areas, with values exceeding regulatory thresholds by factors of three to seven. Cadmium levels were also above acceptable limits at several sampling points. Organic matter content and soil pH were measured to assess factors influencing metal mobility and bioavailability. The study also documented land use patterns around the mining corridors, noting increasing encroachment of farming activities into contaminated zones. These findings highlight the urgent need for environmental monitoring programmes and remediation strategies tailored to artisanal mining communities in North West Nigeria. Recommendations include community-based environmental education, enforcement of buffer zones between mining and farming activities, and phytoremediation trials using locally available plant species. Keywords: heavy metals, artisanal mining, soil contamination, Zamfara State, NESREA.