Levels of some heavy metals in cassava and plantain from farmlands in Kaani and Kpean in Khana Local Government Area of Rivers State

Abstract

The concentrations of heavy metals (Ni, Zn, Cu, Pb and Fe) were determined in cassava and plantain from farmlands in kaani and Kpean Communities in Khana Local Government Area of Rivers State, Nigeria. Samples were collected, prepared, digested and analyzed using AAS. The levels of heavy metals obtained for cassava samples from Kaani were Ni (5.71 mg/kg), Cu (2.45 mg/kg), Fe (92.4 mg/ kg), Pb (6.57 mg/kg), Zn (9.64 mg/kg) and for plantain samples; Ni (4.31 mg/kg), Fe (59.8 mg/kg), Cu (1.89 mg/ kg), Pb (3.69 mg/kg), Zn (7.04 mg/kg) were recorded. The levels of heavy metals obtained for samples from Kpean were Ni (4.09 mg/kg), Cu (9.64 mg/kg), Fe (6.34 mg/ kg), Pb (13.44 mg/kg), Zn (0.22 mg/kg) for cassava and Ni (10.23 mg/kg), Cu (18.53 mg/ kg), Fe (30.50 mg/kg), Pb (39.18 mg/kg), Zn (9.25 mg/kg) for plantain. Results showed that the levels of these heavy metals Ni, Cr, Cu, Pb and Fe in these food crops were found to be  relatively high when compared with FAO/WHO recommended values with crops from Kpean farms having  higher values. The most essential element Zn was found to have values below the acceptable limits for cassava and plantain from both farmlands.