Heavy Metal Contamination in Green Leafy Vegetables Irrigated with Wastewater Collected from Harar Town Vegetable Farm, Ethiopia

Abstract

Food safety issues are of growing concern to consumers globally because of the risks associated with consumption of foods contaminated with heavy metals. In Harar town, Kebele 05 vegetable farm is known to produce vegetables irrigated with wastewater. To what extent these vegetables are contaminated with heavy metals was not known. Thus, a laboratory based cross sectional study was conducted from October 2016 to January 2017 to assess the extent of heavy metal contamination of vegetables. Accordingly, a total of 72 samples from four leafy vegetables namely lettuce (Lactuca sativa), spinach (Spinacea oleracea), kale (Brassica carinata)) and cabbage (Brassica oleracea) were determined. Lead (Pb), Cadmium (Cd), and Chromium (Cr) concentration was determined using atomic absorption spectrophotometry. In all the vegetables, the mean concentrations of Pb, Cd and Cr were 0.17, 0.62 and 1.78 mg/kg, respectively in all vegetables. Cd was found in level more than the maximum limit recommended by FAO/WHO but the level of lead was within the normal range for all vegetables. Chromium was found also within the normal range in all vegetables except in lettuce. The findings of this study have important information on the implications of public health by sequestration of heavy metals to these leafy vegetables then to among vegetable consumers of Harar town and the surroundings. Thus, it is recommended that the concerned public health authorities need to create awareness in the community and discouraging the use of untreated wastewater for cultivating vegetables.

Keywords: Contamination, Heavy metal, Vegetables, Wastewater

DOI: 10.7176/FSQM/94-03

Publication date: February 29^th 2020