Assessing the level of heavy metals concentration in soil around transformer at Akoko community of OndoState, Nigeria

Abstract

Some heavy metals have bio-importance as trace elements but the bio-toxic effects of many of them in human biochemistry are of great concern. The level of heavy metals concentrations of transformer oil polluted soil was assessed in Akungba Akoko community of Ondo State, Nigeria using Atomic Absorption Spectrophotometer. The concentration of heavy metals investigated ranges from: Cu (1400-18)mg/kg, Fe (96700- 15500)mg/kg, Cd (2- 0.5)mg/kg, Mn (62-29)kg/mg, Ni(5-1)mg/kg, Al(27-11)mg/kg, Zn(1400- 44)mg/kg, Pd (68-20)mg/kg and Ca (570- 135)mg/kg. From the study, it was observed that some transformer sites had more concentration of heavy metals than others, as a result of the heavy metals content of the transformer soil released to the surrounding soil, while in some samples of these heavy metals were absent or are below detection limit. Comparing the results with the World Health Organisation (W.H.O) maximum allowable limit in soil with results of the results of different samples collected, majority of the results were found to fall below W.H.O limit which implies that those sites are still contamination free with respect to the specific heavy metal and caution needs to be taken urgently to avoid potential contamination. Meanwhile, heavy metal concentration at some sites have gone beyond the W.H.O maximum allowable limit, calling for immediate remediation of the site.