BIOACCUMULATION OF HEAVY METALS IN SOME SELECTED VEGETABLES HARVESTED FROM THE SAUKA VILLAGE OF ABUJA NIGERIA
Food contamination by heavy metals has become a great challenge for agricultural producers and consumers. The main sources of heavy metals in vegetable crops are their growth media such as soil, air, and nutrient solutions from which the roots or foliage take up these heavy metals. The current study was aimed at determining the concentrations of heavy metals such as lead, chromium, cadmium, copper, and zinc in the soil and some selected vegetables like Ugwu, Waterleaf, Bitter leaf, Spinach, and Scent leaf gotten from Sauka Area, Abuja, Nigeria. The vegetable samples were air-dried and prepared into a powdered form, soil samples were also air-dried and prepared in powdered form, and heavy metals were estimated using an Atomic Absorption Spectrometer. The current study revealed that the concentrations of heavy metals such as copper, zinc, and lead, in all the vegetables harvested from the Sauka area of Abuja, Nigeria, were above the WHO permissible limits, except the concentration of copper in spinach sample, which was below the WHO permissible limit. Chromium and cadmium concentrations were below the WHO permissible limits in the vegetable samples except for cadmium concentration for waterleaf, which was above the permissible limit. Increases in the concentration of heavy metals assayed from the leaf samples were recorded, 13 out of 25 (52 %) leaf samples showed increases in the concentration of heavy metals in the leaf sample compared to their corresponding soil samples, with the least increase of 15.94 % lead concentration in Bitter leaf to 4,455.03 % increase in the zinc content of the waterleaf sample. In conclusion, the percentage increase in the concentrations of heavy metals in some of the harvested plants’ leaves compared to the actual concentrations in the soil suggests evidence of bioaccumulation.
Keywords: Bioaccumulation, heavy metals, Sauka village, vegetables
