Abstract

The objectives of this study was to investigate the chemical fractionation, mobility and bioavailability of Cd, Cu, Mn, Pb and Zn in refuse waste soils of some dumpsites in Zaria metropolis. The heavy metals in the waste soils samples were sequentially extracted and measured using atomic absorption spectrometry. Mean of total extractable metals in the samples analysed for Cd, Cu, Mn, Pb and Zn ranged from 25.86 – 95.71, 1.70 – 446.43, 141.92 – 423.22, 39.9 – 739.10, and 122.45 – 511.57 mgKg^-1 dry weight, respectively. Cd and Pb were mostly found to be in the mobile phase of the samples indicating that the metals are potentially more bioavailable to the environment than the other metals studied. Overall, the order of mobility and bioavailability of the metals is Cd > Pb > Zn > Mn > Cu.

Key words: Heavy metals, Zaria metropolis, dumpsites, bioavailability.