Document Type : Research Article
Department of Pure and Applied Chemistry, University of Maiduguri
The aim of this study was to determine the concentration and conduct risk assessment of heavy metals in some selected vegetables (tomatoes (Solanum lycopersicum), spinach (Spinacia oleracea onion (Allium cepa), cabbage (Brassica oleracea) and lettuce (Lactuca sativa) from Gongolong and Alau Dam agricultural locations. The vegetable samples were digested and analyst using Perkin-Elmer A-Analyst 300 Atomic Absorption Spectroscopy (AAS). The concentration of the studied heavy metals in the vegetables exceeded the maximum permissible limits as specify by Food and Agriculture Organization/World Health Organization (FAO/WHO). Results from average daily intake (ADI) were below the provisional tolerance daily intake and are safe for human consumption. Hazard quotient (HQ) values for all the metals were less than the USEPA permissible limit of 1, and does not pose any serious health risk, except Cd and As from Gongolung agricultural location which indicate potential non-cancer health risk. HI values for Cd and As from Gongolong location and Cu, Ni, Cd, As and Pb were greater than the USEPA threshold limit of 1, indicating server non-cancer health risk. The research therefore recommends regular check of heavy metals in vegetables be conducted so as to protect human health and the environment.