Toxic Metals Uptake by Spinach (Spinacea oleracea) and Lettuce (Lactuca sativa) Cultivated in Sokoto: A Comparative Study
Hannatu A. Sani, A.I. Tsafe, B.U. Bagudo and A.U. Itodo
Potentially toxic metals (Pb, Fe, Mn, Cr, Cd, Zn and Cu) concentration in selected vegetables namely; lettuce (Lactuca sativa) and spinach (Spinacea oleracea) was investigated alongside their harvesting site soil samples using Atomic Absorption Spectroscopy (AAS). Some physicochemical parameters viz; pH, moisture and ash contents of the plant were also determined. The estimated metal concentrations for the vegetables ranges from 1.59-2.07 ug/g, 211-364 ug/g, 7.0-7.5 ug/g, 5.00-5.25 ug/g, 0.01 ug/g, 20.4-24.12 ug/g, 0.8-1.1 ug/g for Pb, Fe, Mn, Cr, Cd, Zn, Cu respectively. The result showed that soils in industrial site are higher in heavy metals and that vegetable grown in the industrial sites is considerably higher in metal content than those grown in normal agricultural soils. It is also observed that vegetables differ in their ability for heavy metal uptake. Highest metal concentrations were observed in lettuce and lowest in spinach.