Determination of Heavy Metals Concentration in Some Selected Vegetables From Mamudo, Potiskum Local Government Area, Yobe State

Abstract

Soil is a vital environmental, ecological and agricultural resource that has to be protected from further degradation as an adequate supply of healthy food is needed for the world’s increasing population. Heavy metals’ accumulation in the soil is of great concern in agricultural production due to the adverse effects on food quality, crop growth and environmental health. The concentration of heavy metals [Zinc (Zn), Iron (Fe), Lead (Pb), Copper (Cu), Cadmium (Cd) and Chromium (Cr)] in vegetables (Tomato fruit and Spinach leaves) and soils (Tomato and Spinach soils) were collected from different farmlands in Mamudo, Potiskum L.G.A of Yobe State and analyzed using Atomic Absorption Spectrometer (AAS). The results revealed all the heavy metals were detected in all the samples with Zn (7.2), Fe (7.5), Pb (4.0), Cu (113.9), Cd (29.1), Cr (4.7) mg/kg respectively for the tomatoes samples and Zn (7.1), Fe (18.3), Pb (21.8), Cu (95.7), Cd (50.8), and Cr (2.7) mg/kg respectively for the spinach. The concentration of the heavy metals were within the normal range World Health Organization (WHO) and Food and Agricultural Organization (FAO) safe limits of 20 – 100, 400 – 500 and 0.5 – 30 for Zn, Fe and Pb respectively in plants samples. But the concentration of the heavy metals were above the normal range WHO/FAO safe limits of 2.5 < 2.4 and < 0.1 – 1 for Cu, Cd, and Cr respectively in plants samples. The high concentration level of Cu, Cd and Cr could be attributed to the high level of metal work, vehicular emissions, addition of fertilizers, pesticides, herbicides and other chemicals to the soil to enhance the agricultural crops. Therefore, the vegetables samples are not safe for consumption with regards to Cu, Cd and Cr.