Determination of Five Heavy Metals in White Yam (Dioscorea Rotundata) and Three- Leaved Yam (Dioscorea Dumetorum) from Farms in Khana, Rivers State

Background: The Niger Delta Region has experienced various levels of pollutions from industries and oil exploration. Studies have revealed that the ongoing pollution is affecting the quality of agriculture produce from this region. Rivers State is one of the states in the Niger Delta and its farmlands have been affected by oil exploration. This study is aimed at determining the levels of five heavy metals (Cu, Fe, Ni, Pb and Zn) in white yam ( dioscorea rotundata ) and three-leaved yam ( Dioscora dumentorum ) using AAS. Research Methodology: The samples used for this study were harvested from farms in Zaakpon and Kaani in Khana Local Government area of Rivers State, Nigeria. Results: Concentration of Cu in white yam (11.86mg/kg) and three-leaved yam (8.90mg/kg) harvested from Zaakpon were found to be higher than those from Kaani, whereas Fe concentration in white yam (43.20mg/kg) and three-leaved yam (144.0mg/kg) from Kaani were higher than those from Zaakpon. Ni and Pb concentration were also higher in the samples from Zaakpon while Zn concentrations in the samples from the two farmlands were below acceptable limits. The dietary intake rate (DIR) values (mg person -1 day -1 ) were calculated using Parkhurst equation and the following was obtained for Cu (0.044 - 0.124), Fe (0.229 - 1.510), Ni (0.0214 - 0.138), Pb (0.001 - 0.141) and Zn (0.022 - 0.145). Conclusion: From the results obtained, it follows that the continued consumption of these crops harvested from the farms will have adverse effects on the consumers. This calls for close monitoring of the farmlands for heavy metal contamination.