DETERMINATION OF SELECTED HEAVY METALS (Cu, Cr, Pb. Ni, Mn AND Co) IN SOIL SAMPLES AROUND MIDROC GOLD MINING IN SHAKISO DISTRICT, GUJI ZONE, OROMIA REGION ETHIOPIA.

Abstract

Soil supports all terrestrial life, and it is a medium in which nearly all food-producing crops grow. However, soil pollution, mainly due to anthropogenic origin, is a significant problem worldwide, affecting soil fertility, plant growth, and human health. Heavy metal contamination of soils is mostly due to mining and smelting of metal ores. Therefore, in this study, soil samples were taken from three sampling sites, such as Dadola, Reji, and Legedembi, around the MIDROC gold mining company to assess the levels of heavy metal contamination of the sampling sites. The soils samples (0 to 15 cm deep) were collected from across 9 sites within three selected areas by using stainless steel applying a random sampling technique. After proper samples pretreatment of dried, crushed and homogenized, known weight of Soils sample was wet digested using 3:2mL of HNO3, of HClO4 for 2:00 hr at 250 oC and Soil samples were prepared through an optimized wet digestion procedure is a material to ensure safety and accurany., and the concentrations of the selected heavy metals (Cu, Cr, Co, Pb, Mn, and Ni) were determined by using FAAS. All these heavy metals statically analyzed by using one way ANOVA are significantly difference (p<0.05). The average concentrations of the heavy metals were found to be in the range of Cu (161.5–312) mg/kg, Cr (127–276.66) mg/kg, Mn (446.27–644.44) mg/kg, Pb (52–77) mg/kg, Ni (25.5–42.83) mg/kg, and Co (13.18–18) mg/kg. The levels of the heavy metals in the soil samples were found in the decreasing order Mn > Cu > Cr > Pb > Ni > Co, and the concentrations of Cu, Cr, Pb, and Mn were above the WHO-recommended limits. This result showed the sampling sites were polluted with heavy metals, and this could affect soil quality, the environment, and human health. Therefore, the concerned bodies should take necessary measures to reduce the effect of soil pollution from MIDROC gold mining companies in the host community.