Heavy Metal Level Evaluation in Commonly Cultivated Vegetables from Different Farming Areas in Kano State

Abstract

Metal toxicity on food substances has been a major cause of diseases and conditions in many parts of the world including African countries. In Nigeria, vegetables, which are an integral part of dishes and delicacies, could be liable to heavy metal toxicity and consumption of such could have devastating health consequences. This study aimed to evaluate levels of some heavy metals in vegetables sources from major farming areas in Kano, Northern part of Nigeria. Samples of some commonly consumed vegetables and irrigation waters were obtained from 4 different farming locations in Kano. The samples including the irrigation waters were oven dried and subjected to digestion processes using acid methods. The solution obtained was used to determine levels of Pb, As, Cd, Ni, Zn and Cu using spectrophotometry. The results showed elevated levels of Pb and Cd in water and vegetables from 2 farming sites compared to other location. The results were also higher than the acceptable limits by WHO/FAO. From these results, it was inferenced that vegetables from such areas have significant higher levels of some of these toxic heavy metals and should be point of concern for food monitoring authorities.