Total Levels of Some Heavy Metals in Cassava Tuber from Eleme Local Government Area of Rivers State, Nigeria

摘要

Cassava tuber obtained from four towns in Eleme Local Government Area were analyzed for Fe, Zn, Cu, Cd, Ni, Pb, Mn and Mg using Perking Elmer AAnalyst 200 model. All the eight metals analyzed were detected as follows: The highest concentration of Fe was obtained from cassava tuber from Onne with a value of 28.80 mg/kg; the level of Zn was highest in cassava tuber from Eteo with a value of 6.59 mg/kg; the level of Cu was highest in cassava tuber from Onne with a value of 1.23 mg/kg; Cd was highest in cassava tuber from Eteo, with a value of 6.89 mg/kg; the highest value of Ni occurred in cassava tuber from Eteo with a value of 5.67 mg/kg; the highest concentration of Pb occurred in cassava tuber from Ebubu with a value of 2.44 mg/kg; the level of Mn was highest in cassava tuber from Eteo with a value of 14.55 mg/kg and the highest concentration of Mg occurred in cassava tuber from Eleme with a value of 36.60 mg/kg. Pearson correlation matrix (PCM) for metal - metal concentrations in cassava tuber samples revealed that there were strong positive correlations between Fe and Cu (0.61) , Zn and Cd (0.78), and Ni and Cd (0.86). Other metals which showed positive correlations were: Fe and Zn (0.50), Pb and Zn (0.42), Ni and Zn (0.54), Pb and Zn (0.06), Pb and Cu (0.23), Pb and Cd (0.15), Mg and Cd (0.08), Ni and Mn (0.22), Mn and Ni (0.43), Mg and Mn (0.18). This indicates that these metals had a common source. A near - perfect negative correlation (R = - 0.99) existed between Mn and Pb, Ni and Cu (- 0.98) and Mg and Zn (- 0.98).