Accumulation and Risk Assessment of Heavy Metals in Vegetables Irrigated with Wastewater in Giza Governorate, Egypt

Abstract

The present study measured the concentrations of heavy metals (Zn, Ni, Pb, Cu, Cr, and Cd) in soils as well as vegetables (faba bean, cabbage, onion, garlic, zucchini, capsicum, eggplant, potato, okra and green bean) irrigated with wastewaterinthe western part of Giza governorate, Egypt.Human health risks to consumers of these vegetables were performed. The study revealed the considerable variations inmetal contents of water, soiland vegetables samples. Generally, wastewater of the study drains was not suitablefor irrigation purpose according to the bacteriological guidelines. Almost all the physicochemical parametersand heavy metals concentrationsof water and soil samples were compatible with the recommended permissible limits of irrigation and agricultural use, respectively. Vegetable species showed remarkable difference in metals concentrations of various plant portion, Zn showed highest tissue concentrations followed byCu. Heavy metalsconcentrationsindifferent edible portionsdecreased in a descending order as Zn > Cu > Pb > Ni > Cr > Cd with low translocation values (< 1) for studiedvegetablesexcept forfaba bean.The health risk index (RI) for humans was low if edible portionsfrom studied vegetables are consumed, in particular Cd, Cr, Pb, and Ni whose concentration valueswere relatively higher than the health based guidelines values. Considering the probable health risk associated with the consumption of contaminatedvegetables, it is important toregularly monitor the levels of metals in wastewater, soils and vegetables in the studied area.

Keywords

• heavy metals
• risk assessment
• vegetables
• wastewater