Comparative Assessment of Selected Heavy Metals in Some Common Edible Vegetables Sold in Yenagoa Metropolis, Nigeria

This study comparatively assessed selected heavy metals in some vegetables (viz: Gongronema latifolium, Amaranthus hybridus, Piper guineense, Talinum triangulare, Telfairia occidentalis and Ocimum gratissimum) commonly used for culinary purpose in Yenagoa metropolis, Nigeria. The samples were purchased from Tombia and Opolo market in Yenagoa metropolis, Bayelsa state, Nigeria. The samples were dried, digested and analyzed using flame atomic absorption spectrometery. Result showed that the concentration of lead, cobalt and cadmium were below detection level. The comparative concentration of other heavy metals in the vegetables ranged from 1.85 - 3.55mg/kg (copper), 1.63 – 14.98 mg/kg (zinc), 5.83 – 186.59 mg/kg (manganese), 8.12 – 31.72 mg/kg (chromium), 5.01 – 16.03 mg/kg (nickel) and 307.60 – 1051.31 mg/kg (iron). Analysis of variance showed that there was significance variation (P<0.05) among the various vegetables. The concentrations of the heavy metals in the vegetables were the below Food and Agricultural Organization/World Health Organization maximum limit apart for iron and chromium. As such, the vegetables from the study area should be consumed with considerable level of safety due to high iron and chromium.