Mine Waste and Heavy Metal Pollution in Betare-Oya Mining Area (Eastern Cameroon) Natanael Tehna 1 , Elisé Sababa 1* , Armel Zacharie Ekoa Bessa 1,2 , Jacques Etame 3 1 Department of Earth Sciences, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon 2 Department of Mining and Geological Engineering, Botswana International University of Sciences and Technology, Private Bag 16, Palapye, Botswana 3 Department of Earth Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon Corresponding Author Email: sababae@yahoo.fr https://doi.org/10.18280/eesrj.060404 ABSTRACT Received: 18 September 2019 Accepted: 5 November 2019 This study includes soils and tailings from the gold mine of four stations (Mari, Mbigala, Mboufa and, Bedobo) in Betare-Oya, eastern Cameroon. These stations have been utilized by Cameroonians and later on by some companies. Soils and tailings were sampled and heavy metal (Cr, V, Ni, Cu, Zn, Hg and, Pb) and radioactive element (Th and U) contents have been determined using ICP–MS techniques. This work deals with the heavy metaldistribution in mining waste and surrounding soils and tailings.The study area is exposed to artisanal gold mining activities. Field observations revealed the soildestructionas well as the environment. All metal values fall below the average shale, except Cr who’s the content is higher than the shale value in soils and tailings. Lead and Th values are above the average shale in tailings. Heavy metal pollution was performed using pollution indices such as enrichment factor (EF), geo-accumulation index (I-geo) and pollution load index (PLI). The overall results reveal that the soils and tailing from Betare-Oya mining area, Eastern Cameroon are only polluted by Cr. These sediments have minor to moderate enrichment; they are unpolluted to moderately polluted with a low contamination level for other metals. Only two stations can be considered as slightly polluted, with minor enrichment and moderate contamination by metals. Keywords: Betare-Oya, mining, pollution indices, pollution, soil, tailing 1. INTRODUCTION Mining can be considered as one of the human activities which negatively influence the environment [1-4]. It usually has as result the destruction of different milieu through the removal of alluvium, flora and burial beneath waste disposal areas [5-7]. Mine waste can be subdivided into two main groups: mine tailings which can be generated when processing the ore, and waste rock produced when the ore is uncover. Various assessments for natural resources include processes such as grinding of rock and metals, recovery of selected element and disposal of the wastes, often as slurry, to a tailing or preservation pond. Finally, almost all the original material may become tailings when low-quality ores are utilized [8-10]. The impacts of mining are the destruction of habitat, the loss of bio-diversity resources and the accumulation of pollutants in various environments [11-13]. Therefore, mining areas have in long term toxicological problem for different ecosystems and human health [5, 14-16]. The exploitation of ore resources create damage in the three various environments: water, atmosphere and, soil. Heavy and radioactive metal elements associated with mining have specific interest for several reasons. They usually show a tendency to accumulate in soils and sediments and have a long tenacity. Metals and radioactive elements are also abundant in soils and sediments derive from both natural and anthropogenic sources. Pathways include inheritance from the parental rocks, application of water and fluvial and/or marine deposition of discharges from dust and mining [10, 17, 18]. At the end, most of metal trace elements, at low values have a crucial role as nutrients for flora, animals, and human health. However, in high concentrations and in some forms, they can be toxic and can cause harm to life [19- 21]. This study is focussed on the evaluation of the physical impact and, the concentrations of trace and radioactive metals in the soils and tailings from mine waste in Betare-Oya district (Eastern Cameroon). This helpedto identify their natural enrichment or anthropogenic sources using physical impact affected by gold mining and heavy metal indices such as enrichment factor (EF), geo-accumulation index (Igeo) and pollution load index (PLI). It also helped to assess the environmental risk of heavy and radioactive metals in the investigated area by comparing the acquired metal values with the average shale from Turekian and Wedepohl [22] and the WHO guidelines. The survey of metals in a mining environment is very useful to assess pollution in the Betare- Oya district and provide basic information for the determination of environmental health risks and management of environmental pollution issues in this area. 2. EXPERIMENTAL METHODS 2.1 Study area The Betare-Oya mining area is located in the eastern region (Figure 1), with a surface area of more than 210 km 2 . It is part of the southern Cameroonian plateau whose altitudes vary between 700 to 900 m. This area is characterized by a hilly landscape [23, 24]. It has a "Guinean sub-equatorial" climate Environmental and Earth Sciences Research Journal Vol. 6, No. 4, December, 2019, pp. 167-176 Journal homepage: http://iieta.org/journals/eesrj 167