Comparative Assessment of Heavy Metal Concentration in Some Edible Spinach (Amaranthus hybridus) in Southern Taraba (Ibi, Wukari and Donga), Nigeria

Abstract

This study focuses on the assessment and comparative concentrations of some heavy metals in spinach (Amaranthus hybridus), cultivated in Wukari, Ibi, Donga local government area of Taraba State in Nigeria. The research is motivated by the indiscriminate use of bulk chemicals for farming activities in the communities under review. The study employed random sampling techniques in collecting the samples of the spinach. The edible part were digested and analyzed for the following heavy metal content: Lead, Zinc, Copper, Nickel, Iron, Cobalt, Chromium, Manganese, and Cadmium. The Atomic Absorption Spectroscopy (AAS) technique was used to analyze the samples. The results for the main concentration of heavy metal were revealed. The concentration of heavy metals in the spinach obtained from the three different samples varies. It was observed that, the sample obtained from Wukari has the highest accumulation of heavy metals. The concentrations of Pb, Mn and Cr were found to be higher than the permissible limits in Wukari spinach. Cd was not detected in the three (Ibi, Donga and Wukari).  Pb was not detected in Ibi and Donga. Cu and Ni were not detected in Donga. Based on the findings from this study, spinach from Ibi and Donga are recommended for consumption compared to Wukari, since most of the heavy metals in this study areas are within the standard permissible limit set by WHO/FAO. Similarly, the daily intake of heavy metal (DIM) and the health risk index (HRI) analysis from the 3 study areas also falls within the acceptable permissible level. Farmers and consumers should be adviced appropriately on the health implications of excessive heavy metal consumption in vegetables.