Study on Accumulation of Heavy Metals in Vegetables Receiving Sewage Water

Abstract

A study was conducted to evaluate heavy metals content of sewage water and its impact on soil and vegetables. Thirty samples each of water, soil, and vegetable leaves and twenty-one samples of edible vegetable portions were collected from different sites, in between Peshawar city and Pakistan. Parameters like pH, and electrical conductivity (EC) were also determined. The pH of sewage water was slightly alkaline; electrical conductivity was with in the safe limit. Heavy metals Cu, Mn, Pb, and Cd, were detected but were found below the toxic level in soil. Levels of Fe, Ni, Cr, and Cd, were observed above the safe level in edible portion of plant while Cu, and Fe, concentrations exceeded in leaves. Zinc was found to be deficient in both water, and soil samples. All the tested heavy metals except Mn, and Cr were found more in fruits than in leaf and root of vegetables while Mn and Cr were found more in root. As some heavy metals were found in excessive amount in sewage water as well as in vegetables irrigated with this water. So it is recommended that vegetables directly consumed in raw form should not be grown with sewage water