Health Risk Assessment of Heavy Metals in Yam and Sweet Potatoes in Wukari

Abstract The health risk assessment of heavy metals in some selected tuber crops (yam and sweet potatoes) was carried out in Wukari. Yam and Sweet potatoes tubers in Wukari and have been serving as stable food and so were also major sources of income. This study was aimed at assessing the concentration of some heavy metals (Pb, Cd,Cr,Cu, Zn and Ni) in some randomly selected selected tubers (yam and sweet potatoes) as well as the health risk in Wukari Local Government Area of Taraba State. The samples were collected from 6 different randomly selected site in Wukari namely; (Mechanic village (A), Sukundi road area (B), Jalingo road area (C), Ibi road area (D) Kente Road area (E) and Rafin kada road area (F)). The samples were washed, peeled, dried, pulverized and analyzed for heavy metal content using the Atomic Absorption Spectrophotometer. The results for the soil samples revealed that the mean values of Pb (108.9 mg/kg), Cd (2.21 mg/kg), Zn (112.8 mg/kg) and Ni (46.12 mg/kg) were above the WHO permissible limit of (85, 0.8, 50 and 35) mg/kg respectively while Cr (0.28 mg/kg) and Cu (12.21 mg/kg) were below the WHO permissible limit of 100 mg/kg and 36.00 mg/kg respectively. Similarly, the heavy metals in the tuber crops also have Pb (7.4- 57.5 mg/kg), Cd (0.2 – 1.9 mg/kg), Zn (20.0 - 40.0 mg/kg) and Ni (0 – 50) above the WHO permissible limit of (2, 0.02, 0.6 and 10 mg/kg respectively), while Cr (0.1-0.4 mg/kg) was below the permissible limit of (1.3 mg/kg) and Cu (0-10 mg/kg) was within the permissible limit of 10 mg/kg for yam and sweet potatoes. The risk assessment analysis revealed that Pb and Cr had the highest and lowest HQ values; 49.30 and 0.11 for yam tubers, 39.25 and 0.13 for sweet potatoes. The highest cancer risk was obtained in Cd (5.1×10-2) and lowest in Cr (1.7 ×10-4). The results of this study are expected to gain public aware ness that consuming locally produced tuber crops from sites contaminated with heavy metals can lead to heavy metal toxicity, leading to liver damage, neural, and respiratory disorders, among others.