Metal Contamination of Canal Versus Sewage Water Irrigated Vegetables in Metropolitan Area of Sargodha, Pakistan
The reduction in the fresh water supply and increase in the domestic effluents with increase in population and urbanization in the Pakistan force the farmers to use untreated sewage water for the irrigation purposes. Besides high nutrient content Sewage water also have source of metal contamination in the food chain. The present field study was conducted to compare the nickel (Ni), copper (Cu) and lead (Pb) contamination in vegetables grown on soils irrigated with sewage water and canal water in Sargodha, Punjab, Pakistan. The Ni, Cu and Pb contamination was assessed using soil quality indices i.e., contamination factor (CF), metal translocation factor (MTF), pollution load index (PLI), geo-accumulation index (Igeo) and ecological risk index (ERI) were calculated in the collected samples. The physico-chemical properties of soil and water samples were determined. Based on the results, it was revealed that sewage irrigated areas were at higher risks of metals contamination compared to canal irrigated areas. From the studied metals, Pb showed highest contamination potential based on the soil quality indices. In sewage irrigated sites, metal concentrations were found higher in edible parts of the vegetables confirming that sewage water contains and supply more metals than canal irrigated water and pose more health and ecological risks.