Comparative Analysis of Environmental Impacts Associated with Surface and Underground Mining Operations

Mining plays a vital role in global economic development, yet it remains one of the most environmentally disruptive activities. This study compares the environmental impacts of surface mining and underground mining, focusing on land degradation, air quality, water contamination, noise pollution, and biodiversity loss. The aim was to assess which mining method poses greater ecological risks and to provide insights for sustainable resource management. A mixed-method approach was employed, combining field data from three mining regions in Nigeria with secondary data from published studies. Indicators measured included suspended particulate matter (SPM, µg/m³), heavy metal concentration in water (mg/L), noise intensity (dB), and percentage of land cover loss (%). Results showed that surface mining exhibited higher land degradation (35% vegetation cover loss) and air pollution (SPM: 180 µg/m³), while underground mining had greater water contamination (Pb: 0.19 mg/L, exceeding WHO standard of 0.01 mg/L) and higher occupational risks. Noise levels were comparable, with underground operations averaging 92 dB against 89 dB for surface mining. These findings highlight the need for tailored mitigation strategies—land reclamation for surface mines and groundwater protection for underground mines. The study contributes to environmental impact assessment frameworks and provides baseline data for sustainable mining policy and regulatory decision-making.