Heavy Metal Content in Vegetables from an Irrigated Farmland in Kaduna Metropolis, Nigeria.

A total of 17 vegetable samples were collected; 7 pumpkin leaves (Telferia occidentalis), 6 bitter leaves (Vernonia amygdalina) and 4 pumpkin leave from control site. Concentration ranges of pumpkin leaves were 0.1-0.30 mg/kg, 1.5-6.20 mg/kg, 1.3-3.10 mg/kg, 4.0-15.30 mg/kg and 4.1-10.20 mg/kg dry weight for Cd, Cr, Cu, Pb and Zn respectively while for bitter leave the concentration ranges from 0.3-1.00 mg/kg, 2.0-9.50 mg/kg, 0.8-3.40 mg/kg, 4.4-7.50 mg/kg and 5.8-12.70 mg/kg dry weight for Cd, Cr, Cu, Pb and Zn respectively. The mean concentrations of pumpkin leave samples studied were found to follow the decreasing orders; Pb > Zn > Cr > Cu > Cd respectively. However, for bitter leave the mean concentration decreases in this order; Zn, Pb, Cr, Cu and Cd. There is correlation between some metals in both vegetable samples. The concentrations of heavy metals are within tolerable levels except Pb in pumpkin leaves that have values which are higher than the WHO/EU recommended values. The slightly high level of Pb in the pumpkin vegetable could be attributed to deposits of the metal from vehicle emissions.