Health Risk Assessment for Carcinogenic and Non-carcinogenic Heavy Metal Exposures from Pepper Fruits Cultivated In Katsina State, North West Nigeria
Authors: Yaradua A. I. , Alhassan A. J. , Nasir A. , Matazu S. S. , Usman A. , Idi A. , Muhammad I. U. , Shuaibu L. , Ibrahim H. 
Published: November 2019

This study was conducted to determine the heavy metals concentration in pepper fruits cultivated in Katsina state Nigeria. The objectives were mainly to detect the presence of heavy metals in the cultivated pepper fruits in the study area, compare the concentration of heavy metals in samples in relation to the permissible limits specified by WHO/FAO/USEPA Standards. Samples of the pepper fruits were collected in the year 2017 from the selected area. Analysis for the concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by Atomic Absorption Spectrophotometry) method. The health risks to the local inhabitants from the consumption of the samples were evaluated based on the Target Hazard Quotient. The possibility of cancer risks in the samples through intake of carcinogenic heavy metals was estimated using the Incremental Lifetime Cancer Risk. Results from this study has shown that with the exception of the mean values for the heavy metal Pb (1.200-1.333 mg/kg), the mean concentration range (mg/kg) values of Fe (0.901-0.967), Zn (0.899-0.911), Mn (0.250-0.287), Cd (0.053-0.0556) in the samples were generally lower than the USEPA, WHO/FAO maximum permissive limits. With the heavy metals Cr and Ni being below detection level (BDL) The results have indicated that the estimated daily intake (EDI) of the heavy metals were lower than the tolerable daily intake limit set by the USEPA in all the samples. Risk level of Target Hazard Quotient (THQ < 1) was observed for all the evaluated heavy metals for both adults and children. The THQ for the samples were in the decreasing order Mn>Zn>Pb>Fe>Cd, for all the pepper fruits respectively. The sequence of risk was the same for both adults and children although the children had higher THQ values in all cases. 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 and Cd violated the risk. The sampling area trend of risk for developing cancer as a result of consuming the studied samples showed in decreasing order: Funtua senatorial zone > Daura senatorial zone> Katsina senatorial zone for both adult and children. The Cumulative cancer risk (∑ILCR) of all the studied pepper fruits reached the moderate risk limit (>10−3) in adults, while in children it is above the moderate risk limit (>10−2). Among all the studied samples, pepper sample from Funtua senatorial zone has the highest chances of cancer risks (ILCR 6.863273 × 10−3 in adults; ILCR 1.715815 × 10−2 in children) and pepper sample from Katsina senatorial zone has the lowest chances of cancer risk (ILCR 6.260100 × 10−3 in adults; ILCR 1.565025 × 10−2 in children). The study suggests that consumption of the studied pepper fruits in Katsina state is of public health concern as they may contribute to the population cancer burden.