Comparative Assessment of Heavy Metals Concentration in the Soil in the Vicinity of Tannery Industries, Kumbotso Old Dump Site and River Challawa Confluence, at Challawa Industrial Estate, Kano State, Nigeria

Abstract

The objective of this research work was to compare the concentration of heavy metals (Ni, Zn, Cu, Cr, Co, Cd, Pb) in the soil samples from the vicinities of four tanneries (Mahaza, Fata, Mario, GLT); Kumbotso old dump site; River Challawa confluence and Yan-sama town at Challawa industrial estate, Kano state Nigeria using atomic absorption spectrophotometry (AAS). The results obtained in the soil ranged between (29.45-14.10μgg^-1) Ni, (18.50-9.70μgg^-1) Zn, (37.85-25.74μgg^-1) Cu, (56.95-25.00μgg^-1) Cr, (14.10-9.00μgg^-1) Co, (21.65-11.65μgg^-1) Cd, (17.45-9.85μgg^-1) Pb. Soil samples from Kumbotso old dump site recorded the highest means values of both Ni and Cr which might  be attributed to the facts that all the tanneries around the area dumped their waste directly .The levels of the all determined metals are relatively lower in the soil samples from the control site (Cu exclusive), suggesting the possible mobility of the metals from the point source to the neighbouring environment either through leaching or runoffs or both. The levels of some of the metals in both areas were higher than the FEPA and WHO permissible limits. Therefore, people living around the area and the consumption of agricultural products grown within the area are prompt to heavy metal contamination as the time of this research work unless an urgent step is taken by the relevant agencies.