Metal(loid)s in maize grains and health risks: A review

Metal(loid)s pollution is the severe issue associated with the food security and human health due to its rising economic and societal development. Keeping this thing in mind, we have investigated the health implications of metal(loid)s including As, Cr, Hg, Cu, Pb, Ni, Zn, Cd, Mn, Fe and Co in maize grains. The data was compiled from the 120 previously published papers carried out between 2015 and 2025 using major scientific databases. Relevant information on metal(loid) concentrations was collected, and computed for human health risk assessment. The worldwide average content of metal(loid)s in maize grains are as: Fe (89.78) > Zn (23.21) > Mn (9.53) > Cr (6.26) > Pb (6.19) > Cu (4.22) > Ni (2.87) > Co (1.08) > As (0.87) > Hg (0.49) > Cd (0.44 µg g⁻¹). Country wise analysis indicated greater amount of Zn, Mn, Fe, Cu and Pb were observed in India, whereas, Ni, Cu, Pb, Mn, Zn and Cd levels were found in Iran. Similarly, As, Cr, Cu, Mn, Ni, Pb and Zn exhibited greater levels in China. In contrast, Italy had higher level of Co, Cu, Zn, Pb and Cd. In Asia and Africa the average content of As, Cr, Pb, Hg, and Zn exceeded the permissible limit set up by Codex, European Union and FSSAI agencies. Results of human health risk evaluation were enumerated in adults and children, where hazard quotient values for As and Pb were recorded less than one, representing no risk. Furthermore, carcinogenic risk inferences revealed low hazard associated with these metals Ni, Pb, As and Cr. The data and methodological strategies employed in this review may assist policymakers/decision makers/environmentalists to develop strict regulations and able management strategies focused at reducing metal(loid)s contamination for maize production across polluted agricultural areas, thereby promoting food safety and reducing potential health risk.