DETERMINATION OF LEAD, CADMIUM AND ARSENIC CONCENTRATIONS IN SELECTED AGRICULTURAL SOILS IN UYO LOCAL GOVERNMENT AREA OF AKWA IBOM STATE

This study was carried out to determine the concentrations of Pb, Cd and As in selected agricultural soils in Uyo Local Government Area of Akwa Ibom State, South South Nigeria. Ten composite samples were obtained at 0-15 cm and 15-30 cm depths from three locations namely: Eniong Offot, Ikot Oku Ikono and Idoro. Routine methods were used to determine the physicochemical properties of the soils, while the heavy metal concentrations were determined by the HCL extraction method. The results obtained indicated high sand contents (84.60%-89.60%), high base saturation (60.78%-63.37%), moderate available P (9.26-15.12mg/kg), slightly acidic to strongly acidic soil pH, low EC (0.010-0.121dS/m), total N (0.10-0.16%), organic matter (1.72-2.31%), exchangeable acidity (2.60-2.81cmol/kg), ECEC (6.86-7.66cmol/kg) and exchangeable bases. Lead (1.66-4.22mg/kg) and Arsenic (0.05-0.81mg/kg) concentrations were low and below the maximum permissible limits, whereas the concentrations of Cadmium (0.81-2.41mg/kg) were high and above the maximum permissible limits for agricultural soils. Cultivation of heavy metals tolerant species like Indian mustard, Rye, oats, legumes, regulation and sanitization of potassium and nitrogenous fertilizers as well as common herbicides and the subsequent practices of soil replacement and immobilization techniques are recommended practices that could be used to remediate the affected soils.