Concentrations and Risk Evaluation of Selected Heavy Metals in Amaranthus (L.) Leaf Cultivated in Katsina State, North West Nigeria

Abstract

Bioaccumulation of seven heavy metals (Cr, Cd, Fe, Ni, Mn, Pb and Zn) in  Amaranthus leaf cultivated in Katsina state Nigeria were measured using atomic absorption spectrometer. The health risks to the local inhabitants from the consumption of the Amaranthus leaf were evaluated based on the Target Hazard Quotient. The possibility of cancer risks in the Amaranthus (L.) leaf through the intake of carcinogenic heavy metals was estimated using the Incremental Lifetime Cancer Risk. The target hazard quotient was (THQ)>1, indicating that the Amaranthus leaf cultivated may pose a non-carcinogenic risk for all the studied metals. Hazard index (HI) was low. The incremental cancer risk (ILCR) for Cd  violated the threshold risk limit (>10−4) and ILCR for Pb reached the moderate risk limit (>10−3) in all the studied samples in adults, While in children ILCR for both Pb in samples from Dabai, Daura, Funtua, Matazu and Zango and Cd for all samples have reached the moderate risk limit (>10−3), while the ILCR for Pb in samples from Birchi, Dutsinma, Kafur, Katsina and Malunfashi are beyond the moderate risk level (>10−2). The study suggests that consumption of Amaranthus leaf cultivated in Katsina may contribute to the population cancer burden.