Physicochemical Characterization and Risk Environmental Trace Metals in Soils and Sediments Near the Abandoned Mine of “El Abed” Pb-Zn Deposit–Northwest Algeria

This study examines the El Abed region, a major lead and zinc mine in northwestern Algeria. Despite being one of the largest mining operations in the area in the past 30 years, the mine has been abandoned since 2004, leaving behind a large backlog of mining waste. Fifty-six samples, including soil, sediment and tailings, were collected to verify physical properties. To measure concentrations and sources of heavy metals in surface samples, chemical analyzes were performed using an iCAP 7000 ICP Series Optical Emission Spectrometer.The physical and chemical properties of the surface samples showed that the pH ranged between 6.25 and 8.4, indicating alkalinity. Moderate to high electrical conductivity values were observed, ranging up to 5040 μS/cm. Eh values ranged from -78 to 53 mV, indicating appropriate reduction. The results showed that the average metal concentrations are: (As = 30.82), (Pb = 1219.27), (Zn = 2855.94), (Cu = 5.3) mg/kg. According to the results, all metals, except copper, meet the GBV standards for levels found in the Earth's crust. Pollution indicators revealed high values that exceed all usual classifications. Mining activity has increased concentrations of lead, zinc, copper and arsenic. The results of this study will assist in decision making and facilitate the development of effective remedial methods to reduce the environmental risks associated with the abandoned Al-Abd mine.