Evaluating Health Risks of Using Treated Wastewater for Vegetables under Desert Conditions

Abstract

This paper evaluated the effect of irrigation with treated municipal wastewater on the accumulation of heavy metals (Cu, Zn, Fe and Cr) in soils and food crops and potential health risks to human via consumption of these food crops. The highest concentrations of Fe, Cu and Cr were found in lettuce, radish and carrots, respectively. Bioaccumulation factors (BAF) for heavy metals in different vegetables showed a trend in the order: Fe>Zn>Cu>Cr. The trends of estimated dietary intake (EDIs) for adults were in the order of Fe>Zn>Cr>Cu. The highest levels of total coliforms were recorded in spinach, followed by radish, eggplant, tomatoes and lettuce. The low uptake of heavy metals by vegetables shows that the health risks for human are insignificant. The results suggest that human health risk to heavy metal contamination can be significantly reduced by selecting appropriate crops.