Trace metal contents of vegetables in Ogbedigbo Afor, Delta State, Nigeria

Abstract

The study investigated the contents of trace metals (Pb, Cu, Zn, Cr and Fe) accumulated in five vegetables: Talinum triangulare (waterleaf  plant), Vernonia amygdalina (bitter leaf plant), Ocimum gratissimu (scent leaf plant) and Telfairia occidentalis (fluted pumpkin) obtained  from two different locations in Ogbedigbo Afor Delta State Nigeria, using Atomic Absorption Spectrophotometer (ASS) based on dry  weight of the vegetables. The results of the trace metal contents in the vegetables ranged as follows: Pb (2.642-3.30 mg/kg), Cu (0.377-  0.864mg/kg), Zn (0.377mg/kg to 0.864mg/kg), Cr (<0.001-0.007mg/kg) and Fe (16.9-25.16mg/kg). The amount of Zn, Cu, Fe and Cr  detected in all vegetables are typically lower than the FAO/WHO permissible thresholds while Pb concentration were significantly above  these guidelines. Statistical analysis of trace metal concentration in Talinum triangulare, Vernonia amygdalina Ocimum gratissimu and  Telfairia occidentalis from the two locations, samples indicated significant differences in Pb, Cu, Zn, Cr and Fe concentration with Zn and  Fe showing maximum bioconcentration in all samples. The bioconcentration of Cr and Pb even at minimum accumulation within safe  limit of FAO/WHO endangers locals who frequently eat these vegetables. Thus, governmental agencies must regulate and constantly monitor anthropogenic actions to decrease hazardous metals undue accumulation in the ecosystem food sequence. The study has a  great implication in environmental monitoring and management.