Analysis of Heavy Metals Content of Fluted Pumpkin (Telfairia occidentalis) Leaves Cultivated on the South Bank of River Benue, Nigeria

Abstract

Assessment of heavy metals (Fe, Mn, Zn, Cu, Cd, Cr, and Pb) content of fluted pumpkin leaves (Telfairia occidentalis) cultivated along the bank of river Benue at Makurdi, Central Nigeria was done using atomic absorption spectrophotometery (AAS). The concentration of these metals was also determined in the soil and river Benue water samples. The results show the mean concentration of heavy metals in T. occidentalis leaves samples as: Fe (54.7±21.9 mg/kg), Mn (278± 156 mg/kg), Zn (50.4± 9.2 mg/kg), Cu (5.03± 1.1 mg/kg), Cd (0.760± 0.2 mg/kg), Cr (3.78± 2.9 mg/kg) and Pb (44.05± 22.6 mg/kg). The load of heavy metals in fluted pumpkin leaves' samples increased in the order Cd<Cr<Cu<Pb<Zn<Fe<Mn. This correlates with the trend of observed heavy metals content in the order Cd<Cu<Cr<Pb<Zn<Mn<Fe for the analysed soil and water samples. The concentrations of Fe, Mn, Zn, and Cu in the vegetable were below Codex Alimentarius limits while Cd, Cr and Pb values exceeded their permissible limits in vegetable samples set by Codex Alimentarius Commission. Thus, there is a need to continuously monitor the heavy metal content of food crops cultivated along the banks of river Benue and other such places.

Keywords: Atomic absorption spectrophotometry, Fluted pumpkin (Telfairia occidentalis), Heavy metals, River Benue