Assessment of Some Heavy Metals in Cereal Samples from Bayo and Hawul Local Government Areas, Borno State, Nigeria

Abstract

Bayo and Hawul local government areas are known for large production of cereal for consumption and commercial purposes, and uses tones of agrochemicals to increase yield. Long-term use of agrochemicals result in accumulation of heavy metals in soil and subsequent absorption by plant, hence the need to asses level of heavy metals in the cereal samples (sorghum and maize). Atomic Absorption Spectroscopy (AA-6800 SHIMADZO) was used to determine concentration of heavy metals in cereal samples collected from agricultural locations in Bayo and Hawul local government areas. When compared with joint safety limit of WHO/FAO, the levels of heavy metals in cereal samples were higher in most of the agricultural locations. The average daily dose (ADD) of the heavy metals computed for cereal samples were above the tolerable daily intake. The levels of heavy metals exposure due to consumption of cereals were above the acceptable risk levels (ILCR > 10-4 ), suggesting an individual developing cancer over a lifetime is of high probability. There is potential health risk for humans through the consumption of the studied cereal as revealed by high values of hazard quotient (HQ). Moreover, hazard indices (HI) of all the metals due combined non-cancer effects in the study were greater than one (1), suggesting potential health risk. As, Cd and Pb show consistency through consumption of the studied cereal samples and should be given priority to public health concern because of health risk associated with these heavy metals