The present study was initiated with the objective to investigate the effect of artisan mining activities on soil degradation and contamination with mercury and cyanide used in gold extraction. The area of study was around AlSada village located at the northern western part of Gadarif state (eastern Sudan). sites collected were according of intensity of mining activities as high (site 1) or medium (site 2) or without mining activity referred to as reference site. Soil samples were collected using a probe to a depth of 3 meters. 5 samples from site 1 and 3 from both site 2 and reference site. The sampling from each site included the three types of soils (sandy, clay and silt). so for site 1, 15 samples were analyzed, and 9 for each site 2 and reference site. Soil samples were also taken from gold tailing. Soils samples taken from the sites were analyzed for phsi-chemical properties. Samples taken from tailing were analyzed for lead and cyanide. Physical characteristics included texture and organic matter. Chemical analysis included pH, electrical conductivity (EC), Soluble cations and anions, Sodium Adsorption Ratio (SAR), Exchangeable Sodium Percentage (ESP). The cations analyzed in saturation extracts were Ca, Mg, K, and Na, while the anions are SO4 (sulfate), CO3 (carbonate), HCO3 (bicarbonate) and Cl (chloride). The results obtained showed that the exchangeable cations showed significant (P≤0.05) lower values compared with the reference site. P concentration was the highest in the reference site, followed by site 1 (P≤0.05), then site 2 and mine tailing (P≤0.05). Cation exchangeable capacity (CEC) level was the highest (P≤0.05) at the reference site, followed by site 2 and site 1. CaCO3% was the highest (P≤0.05) at the reference site, showing the effect of the mining activity. For the heavy metals, lead showed higher levels than normal in all sites and was significantly affected by interactions of site with mine tailing. For cyanide a significant interaction was found for mine tailing with reference site. Most participants’ complaint about the negative impact of mining activities in the area due to vegetation removal and animal deaths from poisoning both affected their income the change in migration routes. Most did not think mining had contributed to the development of the area and most would not change lifestyle and join in gold mining. Health hazards were due to air, soil and water pollution. Hazards for workers are due mercury inhalation.
Ahmed et al. (Mon,) studied this question.