Health Risk Assessment of Heavy Metals in Soil Rhizosphere and Onion Bulbs Cultivated in Danbam Farmlands, North East, Nigeria

Abstract

Elisha Karu*, Buhari Magaji, Aishatu Umar Maigari and Fauziyya Aliyu Jibo

This study was conducted to determine the levels of heavy metals (Cd, Cr, Mn, and Pb) in soil rhizosphere and onion bulbs from four locations in the Danbam area of Bauchi State Spectrophotometry method were employed for the determination of the concentrations of the metals. The concentrations of all the heavy metals were found to be in the range 4.06 × 10^-8 to 1.91 × 10^-1 mg/kg which are below the permissible level (0.02, 500, and 0.3 mg/kg for Cd, Mn, and Pb respectively) set by FAO/WHO. The study also revealed that daily metal intake (DIM), hazard quotient (HQ), and hazard index (HI) were below unity and points to the nonexistence of potential public health. Calculated bioconcentration factors (BCF) suggested a higher concentration of heavy metal ions in the soil than in the onion bulbs and did not portray any risk to public health.