Trace metals in vegetables grown with municipal and industrial wastewaters

Abstract

By inducing elevated concentrations of certain trace metals in soil, irrigation with domestic and industrial wastewater creates a potential risk to human health. This study was conducted to assess the concentrations of the trace metals Cd, Cr, Cu, Ni, and Pb in some vegetable crops irrigated with industrial and municipal wastewater and to estimate the potential health risks of these metals to humans via the consumption of those foods (eggplant, pepper, and tomato). Vegetable samples from wastewater-irrigated fields were collected from 17 locations around Gaziantep City in Southeastern Turkey. The mean concentrations of Cd, Cr, Cu, Ni, and Pb in edible portions of eggplant, pepper, and tomato were 0.17 (0.01–0.52), 2.6 (1.4–4.8), 16 (7.41–60.54), 2.9 (0.6–6.1) and 0.70 (0.08–4.48) mg kg−1, respectively. Cr, Cu, and Ni concentrations in all the 38 vegetable samples exceeded the Food and Agriculture Organization and World Health Organization (FAO/WHO) and the World Health Organization and European Union (WHO/EU) limits, Cd concentrations in 36 samples exceeded the WHO/EU and in 14 the FAO/WHO limit, Pb concentrations in nine samples exceeded the FAO/WHO and in 24 samples the Turkish regulations. These values indicate that the consumption of vegetables irrigated with industrial and municipal wastewater may represent an important exposure pathway to humans. Monitoring of wastewater-irrigated vegetables is essential to reduce or eliminate unnecessary risks.