Abstract

The accumulation of As, Cd, Cr, Pb and Zn in soils and vegetables in the vicinity of Enyigba Lead mine were investigated using Particle Induced X-ray Emission (PIXE) spectrometry. Samples from Abakaliki served as control. The five edible vegetables studied include Telfaria occidentalis (fluted pumpkin); Talinum triangulare (water leaf); Amaranthus hybridus (Amaranth or pigweed); Vernonia amygdalina (bitter leaf); and Solmun nigrum (garden egg leaf). The metal concentrations in the soil decreased with depth which possibly suggests anthropogenic sources of contamination. The levels of Pb > Ni > Cd in Enyigba top soil was observed to be above the US-EPA Regulatory Limits in that order. Elevated concentrations of heavy metals were recorded in all the vegetable samples from Enyigba Lead mine and they exceeded those of Abakaliki. The results revealed that heavy metal values in the vegetable from Enyigba ranged from 0.035mg kg^-1- 0.400mg kg^-1 (As), 0.001mg kg^-1-0.01mg kg^-1(Cd), 0.023mg kg^-1-0.273mg kg^-1(Cr), 0.105 mg kg^-1-0.826mg kg^-1 (Pb), and 0.016mg kg^-1-0.174mg kg^-1 (Zn); while those from Abakaliki were found to be 0.022mg kg^-1-0.280mg kg^-1(As), 0.002mg kg^-1-0.009mg kg^-1(Cd), 0.023 mg kg^-1-0.210 mg kg^-1(Cr), 0.091mg kg^-1-0.426mg kg^- (Pb) and 0.022mg kg^-1-0.144mg kg^-1(Zn). The levels of arsenic and lead in bitter leaf and garden egg leaf exceeded WHO Maximum Limit (WHO-ML = 0.1ppm for As and 0.3ppm for Pb). The variation in the parameters determined were found to be statistically significant (p<0.05) as determined by one way analysis of variance.

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