Health risk assessment of potentially toxic elements via consumption of vegetables irrigated with polluted river water in Addis Ababa, Ethiopia

Abstract

Background: Vegetables grown at contaminated sites can take up and accumulate toxic and potentially toxic elements at concentrations that are toxic to human health. The present study determined the levels of potentially toxic elements/PTEs in irrigation water, soil and vegetable samples grown along contaminated river and assessed the potential health risks to consumers. Results: The average concentrations of Mn, Sr and Cr in the irrigation water were higher than the international guideline values. The levels of As, Cr, B and Ni in most of the farm soils were also found to be higher than the guideline values. Other PTEs, although not exceeding the recommended limits were relatively high in the soil and water samples. The study also revealed that the mean levels of Cr, Cd and Fe in most vegetables were higher than the maximum recommended limits. Swiss chard was maximally contaminated with PTEs followed by lettuce, cabbage, Ethiopian kale, carrot and potato. Hence, frequent consumption of lettuce and Swiss chard may cause serious health risks to consumers. Conclusion: The levels of many elements were varied with location, suggesting localized inputs of the various contaminants related to industrial and other activities that generate wastewater.