Assessment of trace metals in soil and vegetable samples irrigated from Borkena River, South Wollo Zone, Amhara Region, Ethiopia

Abstract

Due to rapid industrialization and urbanization, large quantities of wastes are released into the rivers of Kombolcha city. The vegetables grown on the polluted sites can take up potentially toxic trace metals at concentrations, which are toxic to human health. The current study determined the amount of potentially toxic trace metals in soil and vegetable samples grown around polluted river and assessed the potential health risks to consumers. Samples were collected in June 2020, digested using the wet digestion method and analyzed quantitatively using inductively coupled plasma optical emission spectrometer (ICP-OES). The concentrations of selected trace metals in soil samples were much lower than the recommended limit; however, the levels of nickel, lead and cadmium in vegetable samples were above the international guideline values. The result also indicated that the average target hazard quotient of lead, nickel and cadmium in most studied areas were higher than the limit. The target hazard quotients of these potentially toxic trace metals were higher in lettuce vegetables especially in children consumer. Thus, frequent consumption of lettuce may cause a health risk in children. Keywords: Contamination, kombolcha city, soil, vegetable, trace metal