Impending Pollution of Betare Oya Opencast Mining Environment (Eastern Cameroon)

Abstract

Mining resources are offered by the natural milieu and liable to exploitation. Raw materials extracted are essential for jewellery and economy. But in most cases, the environmental impact assessment is disappointing. In this study conducted at Betare Oya, mining residues are directly disposed in the immediate environment without passing through the tailing ponds for treatment, despite environmental laws and standards. Soluble components of matter are slowly dissolved, drained by meteoric water and flowed into tail bay vicinity. Soil and mining residues were sampled in Mari, Mbigala, Mboufa and Bedobo, respectively, four sub-watershed of Lom, the main river of the region. Concentration of nine MTE (metallic trace elements): As, Cd, Cr, Cu, Co, Ni, Pb, Zn and Hg were determined by ICP-MS (inductively coupled plasma-mass spectrometry). Highest concentrations of trace and toxic metals in soil and mining residues are: Cr (210 mg·kg -1 ) > Zn (136 mg·kg-1) > Ni (64 mg·kg-1) > As (34 mg·kg-1) > Cu (30 mg·kg-1 ) > Pb (25 mg·kg-1) > Co (17 mg·kg -1) > Cd (0.5 mg·kg-1) > Hg (0.1 mg·kg-1), respectively. These results let assume that it is a risk of environmental pollution and poisoning relative to these elements around Betare Oya opencast mining area, with impact on human health.