Detection of Heavy Metals in Some Edible Grains Obtained from Two Markets in Bauchi Metropolis, Nigeria

Abstract

This study investigated the level of heavy metals (Cd, Cr, Cu, Fe, Pb and Zn) in grains sold in Central and Muda Lawal markets in Bauchi.  Our objectives include assessing heavy metal concentrations in the grains and evaluating associated health risks. We utilized Atomic  Absorption Spectrophotometry following acid digestion of grains to determine heavy metal concentrations. In Central market-sourced crops, the mean concentrations of Cd, Cr, Cu, Fe, Pb, and Zn were 0.06, 0.49, 0.21, 1.16, 0.15, and 0.17mg/kg respectively. Meanwhile,  crops from Muda Lawal market exhibited mean concentrations of 0.06, 0.58, 0.17, 1.62, 0.1, and 0.22 mg/kg for Cd, Cr, Cu, Fe, Pb, and Zn,  respectively. Cd, Cr, Cu, Pb, and Zn levels were below the permissible limits. However, Fe exceeded permissible limits in small beans, Syria  maize, and white guinea corn from Central market, as well as in Syria maize, Pearl millet II, and white guinea corn from Muda Lawal  market. The daily intake of Cd, Cu, and Pb from most studied crops exceeded the oral reference dose, posing potential health risks.  Conversely, Cr, Fe, and Zn intake levels were within acceptable limits, posing minimal health risks. Hazard quotient and hazard index  values were below 1, suggesting that crop consumption is unlikely to pose health risks.