Abstract:
Accumulation of different metals and metalloids was assessed in a potential vegetable crop, turnip (Brassica rapa L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City, Pakistan. Two sites at a distance of 15 km radius were selected for this study. The levels of different metals and metalloids such as Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd and Pb, at site-I were 0.06, 15.8, 34.4, 13.5, 1.95, 3.15, 4.25, 41.5, 1.68, 4.79, 8.76, and 27.5 mg kg-1, whereas those at site-II were 0.07, 23.7,41.9, 20.2, 3.70, 3.63, 9.64, 47.08, 2.73, 5.85, 19.09 and 33.85 mg kg-1, respectively. In general, the metal and metalloid concentrations were higher at site-II than those found at site-I, except Cd. The concentrations (mg kg-1) of metals and metalloids in the vegetable at site-I following the order of arrangement in the case of soil were, 9.07, 33.66, 28.48, 0.49, 7.64, 18.73, 35.79, 2.53, 0.41, 6.8, 0.58 and 7.28 mg/kg, whereas those at site-II were 17.09, 49.23, 42.05,0.77, 9.95, 15.10, 55.5, 5.21, 0.63, 16.1, 0.66 and 12.6 mg/kg, respectively. At both sites the levels of metals in the vegetable were below the permissible level except those of Mn, Ni, Zn, Mo and Pb. At both sites, the transfer factor ranged from 0.03-216.3 mg kg-1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order Cd > Ni > Se > Zn > Mn > Co > Cr > Pb > Mo > Fe > Cu > As and in the vegetables as Mo > As > Cr > Pb > Zn > Co > Se > Fe > Mn > Ni > Cd > Cu, respectively.