Trace Metal Dynamics in Some Leafy Vegetables Consumed in Warri, Niger Delta Region of Nigeria

Five common and widely consumed Nigerian leafy vegetables Talinumtriangulare (waterleaf), Amaranthusviridis(African spinach), Ocimumgratissimum(scent leaf), Vernoniaamygdalina (bitterleaf) and Telferiaoccidentalis(pumpkin leaf) collected from Ekpan around the Nigerian National Petroleum Corporation (NNPC) refinery were digested and analyzed for trace metal distribution in the leaves and roots using the atomic absorption spectrophotometer. Most of the trace metals analysed (zinc, cadmium, arsenic, iron and lead) were found present in the analyzed sample. The result showed that the levels of iron, lead and zinc ranged from 2.110 to 5.230; 2.890 to 9.999 and 2.801 to 5.821 mg/kg respectively for the roots. The levels of iron, lead and zinc for the leaves respectively ranged from 1.340 to 4.320; 1.321 to 6.871 and 1.340 to 3.014 mg/kg.Values obtained were compared with those available in the literature and within tolerable limits of some regulatory authorities. The bioconcentration factor indicates that the roots of the vegetables concentrate most of the metals than the leaves. The high level of lead in these samples could be attributed to the sampling point which is close to an oil refinery. It is therefore imperative that the operations of oil industry in the study area be sufficiently accompanied by an adequate environmental protection measures.