Levels of Heavy Metals in Selected Leafy Vegetables from Markets in Owerri, Imo State, Nigeria

Abstract

The study assessed the concentrations of cadmium (Cd), lead (Pb), mercury (Hg) and arsenic (As) in Telfairia occidentalis (fluted pumpkin), Talinum triangulare (water leaf), Occimium grattissimum (scent leaf), Murraya koenigii (curry leaf) and Gnetum africana (ukazi)) obtained from the Relief Market, New Egbada Market and Amakohia Market in Owerri, Imo State of Nigeria. The part of each of the leafy vegetables selected for analysis was the leaf. The leaves were prepared by first washing with clean borehole water to remove sand and other dirty materials before they were sun-dried for 6 days and sent to the Spring Board Research Laboratory in Anambra State, Nigeria, for analysis. The determination of the concentrations of the heavy metals in the leaves was done by Atomic Absorption Spectroscopy (AAS), using the standard procedures. Data generated from the samples were subjected to test of significance using Analysis of Variance (ANOVA) at 95% confidence level with SPSS (Statistical Package for Social Science). Results showed that the mean levels of Pb, Hg and As in the leafy vegetables were significantly higher than FAO/WHO (1999 & 2015) safe limits, whereas the mean levels of Cd were lower. Care should, therefore, be taken in the production and handling of vegetables to ensure consumption of toxic free vegetables.