The transfer factor of metals in soil-plant system around an abandoned mine in Abakaliki, Ebonyi state Nigeria

This research assesses the concentration levels of heavy metals in parts of Abakaliki as a result of the lead-zinc mining in the area and its possible effects on human life. Heavy metals in soil and plant samples were analysed using Atomic Absorption Spectrometer (AAS). Physicochemical parameters were determined show that pH is generally low (3.65) resulting from the dissolution of the sulphide Ore. The heavy metal mean trend indicates that Fe > Zn >Pb> Cr >Cu > Ni > AS > Cd in the soil samples. Fe, Zn, Cu, Pb and Cr were observed to be high. The variations for the heavy metals suggest that mining operation is responsible for the distribution and redistribution of chemical elements. The values of contamination factor for the soil indicate moderate contamination for Cd, As and Ni while Fe, Zn, Pb, Cu and Cr show very high contamination. The result of enrichment factor (EF) using Fe concentration as normalizing value show that Ni, Cd, Cr, As, and Cu have depletion to mineral enrichment while Pb and Zn show moderate enrichment. The result of the Correlation analysis and principal component analysis ( R- Mode and Q-mode) applied to the data analysis show that Zn, Pb, Cd, Cu, and Cr heavy metals originated from similar sources but may have been influenced by mining operation while Ni and As are attributed to a geogenic source. Proper sewage disposal practice and soil remediation are recommended.