Concentrations of Cd, Cr, Cu, Pb and Zn in (mg/kg) were determined in topsoil from
irrigated farmland around Kawo area in Kaduna, a town in Northern Nigeria using
Atomic Absorption Spectrophotometer (AAS). The soil physico-chemical parameters, pH
and percentage organic matter (% OM) content were also determined. The soil pH
showed alkaline which ranged from 6.50-7.90 while the soil percentage organic matter
ranged from 0.80-1.86 %. Concentration of Cd, Cr, Cu, Pb and Zn in all the soils samples
ranged from 0.1-4.5, 0.50-30.50, 3.2-13.5, 4.0-28.00 and 5.5-49.7 mg/kg dry weight,
respectively. The mean concentrations of soil samples studied were found to follow the
decreasing orders; Zn > Pb > Cr > Cu > Cd. There is correlation between soil physicochemical
parameters and metals such as Cu and Pb in the soil samples. The
concentrations of heavy metals are within tolerable levels except for Cd. The slightly
high level of Cd could be ascribed to lubricating oils as well as the burning of old tyres
that are frequently dumped close to the site.