Heavy metals contamination in selected vegetables consumed in Dorayi-Babba, Kano and their toxicity to human health

Abstract

Health implications to the populace due to consumption of heavy metals contaminated vegetables have been a great concern all over the world. This research is aimed to assess the level of some heavy metals (Fe, Mn, Pb, Cd, Co, and Cr) in selected vegetables (Garlic, Onion bulb, Onion leaves, Lettuce, Spinach, and Carrot) obtained in Dorayi Babba, Gwale L.G.A, Kano State. In this study, the levels of heavy metals have been determined using atomic absorption spectrophotometer. The average concentrations of the metals determined were in the range of 0.685 – 4.312, 0.108 – 1.049, 0.009 – 0.329, 0.002 - 0.018, 0.026 - 0.096 and 0.079 - 0.662 mg/Kg for Fe, Mn, Pb, Cd, Co, and Cr respectively. Cadmium is not detected in lettuce, this implies that, either its concentration was below the detection limit by the machine or is not present at all. Garlic was found to contain the highest concentration of lead (0.329 mg/kg), while the onion leaves contained the lowest concentration (0.009 mg/kg). The FAO/WHO maximum permissible limit for lead in vegetable is 0.03 mg/kg. The concentration of lead in garlic and carrot were above tolerable limit set by world regulatory bodies. All other heavy metals were within the safety baseline levels/tolerable limits for human consumption. The results obtained were comparable with those available in the literature.