Abstract
Illegal gold mining has developed in recent years in the department of Djekanou with the rising cost of gold on the world market, due to the slump in local agricultural products and the unemployment of young people of working age. It has become an essential activity along with agriculture and farming in rural areas. It is an effective way to fight poverty. However, this practice is likely to cause significant environmental damage. Thus, to assess the environmental quality of this region prone to gold mining activity, the determination of the level of metallic contamination of environmental matrices (soils and sediments) was carried out. Four (4) soil and sediment sampling campaigns took place in dry and rainy seasons on the illegal gold mining site and near the dam, all located at about 685 m from Yobouekro, on the gold washing site of Taffissou at 3,425 m from Djekanou and at Groudji in the department of Djekanou. The sediment sampling was carried out by Strahler's method, while that of the soils was taken at random over the extent of the gold washing sites. The total concentrations of metals in the different matrices were determined by atomic absorption spectrophotometry (AAS). The analytical results show that the metal contents are lower than the natural content of each element in the earth's crust (UCC). Gold mining activities are not currently a source of metallic contamination of the environment. Also, the contamination factors recorded from the concentrations of metals are all less than 1, indicating low contamination of sediments and soils by trace metal elements despite intense gold mining activity. Notwithstanding, the evaluation of the environmental quality from the concentrations of the metals Cd, Co, Cr, Hg and Pb compared to the American guide values SQGs (TEC and PEC), it is noted that the receiving environment is contaminated only by mercury, cadmium and cyanide; the values of the other parameters studied being lower than the guide values. The two matrices mentioned above were also assayed with cyanide and the results revealed that the sites of Groudji and Taffissou are contaminated.
Highlights
Gold panning is a largely informal activity that is carried out without planning, using methods and tools that are often ancestral and rudimentary, a poorly known resource [1]
The concentrations of TMEs in the different matrices at the gold panning and washing sites are recorded in the tables below: 3.1.1
Analysis of the results shows that, of the three gold panning and washing sites that were the subject of this study in the Djékanou region, the Yobouékro and Taffissou sites are affected by MTAs, with the Groudji site being uncontaminated
Summary
Gold panning is a largely informal activity that is carried out without planning, using methods and tools that are often ancestral and rudimentary, a poorly known resource [1]. Long criticized for its devastating social and environmental impacts, gold panning continues to spread throughout the world, especially in Africa. The expansion of this activity in West Africa is due to the decline in sales of traditional agricultural products (cocoa and coffee) and the ignorance of its negative medium- and long-term impacts on the biophysical and human environment by most of the actors involved in the sector [2]. The pollution generated, by cyanides and mercides, is a major problem for Ouattara Bakary et al.: Metal Contamination of an Underground Gold Picking Zone in the Department of Djekanou, Cote D’Ivoire gold miners and the population living near mining sites. In terms of the natural environment, physical degradation can be observed on the sites due to the installation and activities of gold panners
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
