The Effect of Leaching on the Uptake of Heavy Metals (As, Cd, Cr, Ni and Pb) by Pawpaw (Carica Papaya Linn.) Growing in Dumpsite and Near Dumpsite in Amarata, Yelga Bayelsa State

Heavy metals such as; As, Cd, Cr, Ni and Pb were determined in different parts (bark, fruits, leaves and roots) of Carica papaya (pawpaw) growing in dumpsite and near dumpsite. Atomic absorption spectrometry was employed for the analysis of the heavy metals; As, Cd, Cr, Ni and Pb. From the results obtained, some parts of the Carica papaya from the near dumpsite had higher concentrations than the dumpsite due to leaching. These metals were washed off from the dumpsite during wet seasons by running water. The mean concentrations of heavy metals (dumpsite) were 0.23 ± 0.003mg/kg As, 0.26 ± 0.04mg/kg (Cd), 0.45± 0.15mg/kg (Ni) and 0.97 ± 0.18mg/kg (Pb). The mean concentrations of heavy metals in Carica papaya plant from near dumpsite were: 0.023 ± 0.003mg/kg Arsenic (As), 0.26 ± 0.039mg/kg (Cd), 0.49± 0.154mg/kg (Ni) and 0.93. ± 0.181 mg/kg (Pb).The mean concentration of Nickel in all parts of the carica papaya from near dumpsite was higher than the dumpsite. The observed high mean concentration of heavy metals in carica papaya parts from dumpsite is largely due to the composition of the dumpsite. The mean concentrations of lead and cadmium were above the WHO/FAO permissible limits for edible fruits and vegetables while the mean concentrations of Arsenic and Nickel from both locations were below the WHO/FAO permissible limits.