Assessment of heavy metals content in vegetables and their potential human health risk in Bauchi, Nigeria

Abstract

The human dietary uptake of heavy metals through contaminated food crops has led to carcinogenic and non-carcinogenic health concerns in humans. This study evaluates the possibility of developing cancer and non-cancer human health risk in both adults and children from the consumption of heavy metals contaminated vegetables sold in four selected markets in Bauchi, State. Five selected vegetable samples were collected from each market, prepared, and digested and the concentrations of heavy metals (Cd, Pb, Cr and Zn) were determined using the atomic absorption spectrometry test. The mean concentration of Cd in most of the vegetable samples collected from the markets had exceeded the permissible limit set by WHO, while the mean values of Cr, Pb, and Zn were below the permissible limits. The mean values of heavy metals obtained in this study were 0.626, 0.044, 0.04, 0.01 mg/kg, for Zn, Cd, Cr, and Pb respectively. The computed hazard quotient and hazard index values discovered in this study were below the threshold value of 1, indicating that the population (both adults and children) is not at risk of developing non cancer risk. The study, found that the consumption of the selected vegetables for both adults and children will not expose the population to any carcinogenic human health risk. However, continues uptake of these metals over time could lead to potential health risk in both children and adults. Regular monitoring of heavy metals in food crops and screening of metals contents in fertilizer, pesticides and wastewater should be enforced by regulatory agencies.