ASSESSMENT OF METALS AND METALLOIDS IN VEGETABLE CROP IRRIGATED WITH DOMESTIC WASTEWATER IN PERI-URBAN AREAS OF KHUSHAB CITY, PAKISTAN

摘要

Accumulation of metals and metalloids was assessed in a vegetable crop of cabbage (Brassica oleracea L.) irrigated with domestic wastewater in two different sites of a pen-urban areas of Khushab City, Pakistan. From findings, the levels of different metals and metalloids such as Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd and Pb were higher at site-II than those found at site-I. At both sites, the concentrations of metals and metalloids in the vegetable samples irrigated with canal and sewage water were observed below the permissible levels except for Mn, Ni, Zn, Mo and Cd. At both sites, the transfer factor ranged from 0.037-241.0 mg kg(-1) with Cr having the highest transfer factor. The metal pollution index in soil resulted in the following order: Cd > Ni > Se > Mo > Mn > Co > Zn > Cr > Pb > Fe > Cu > As, respectively. The results from this study suggested that significant differences existed in the metals concentrations among the analyzed vegetables and that soil accumulates high concentration of heavy metals to the vegetables when irrigated with wastewater. Thus, farmers should be well-informed on problems associated with excessive usage of fertilizers as well as irrigating the crops with waste and all sorts of polluted water and the needs to grow crops with safe levels of heavy metals.