Heavy Metals Accumulation in the Edible Parts of some Sewage Wastewater Irrigated Vegetable Crops

Abstract

Nowadays, using sewage wastewater in the irrigated agriculture causes hazardous environment impacts. Assessment of these negative effects is vital issue to prevent heavy metals to be introduced in the food chain. Field and laboratory studies were conducted at Ellwan, Mangabad and El-Madabegh villages, Assiut Governorate, in order to evaluate heavy metals concentrations in the edible parts of carrot, turnip and onion plantswhich were irrigated with sewage water (SW). The obtained results indicated that, the soils of the studied villages were contaminated by heavy metals. The concentrations of Zn, Cu, Pb, Cd and Ni concentrations in the edible portion of thesevegetables plants ranged between 45-70, 13-19, 3.8-6.2, 2.85-3.85 and 2-6 mgkg–1, respectively. The obtained results showed that the concentrations of Pb, Cd and Ni in the edible plants were higher than the permissible limit levels but those of Zn and Cu were within the safe limit levels. It is worthy to mention that the irrigated edible vegetable crops especially onion, turnip and carrot with SW should be avoided. This study highlights the potential hazard for human health due to uptake of high concentrations of heavy metals especially Ni, Cd and Pb by the studied vegetable crops.