DETERMINATION OF HEAVY METAL CONCENTRATIONS IN TOP-SOIL OF SOME RESIDENTIAL AREAS OF KADUNA USING ENERGY DISPERSIVE X-RAY FLUORESCENCE (EDXRF)

Abstract

This study assesses the concentration of some environmentally toxic heavy metals in selected residential areas of Kaduna city using Energy Dispersive X-Ray Fluorescence (EDXRF). The study is restricted to the southern areas of the city characterized by high population and industrial activities. Three composite samples of surface soil were collected from each of Barnawa, Narayi and Sabo areas using soil auger within a depth of 0 – 15 cm. Samples were homogenized and subjected to cone and quartering as well as pulverization and sieving, in order to obtain standard particle size for XRF determination of the metal concentrations. The range of mean concentrations (µg/g dry weight) of heavy metals were As (1.0 – 10.7), Pb (467 – 1833), Ni (583 – 753), Cr (267 – 300), Cu (407 – 467) and Zn (31- 320), respectively. The mean concentration of Cd was constant (1.0) for all locations. The mean concentrations of As  and Cd were generally below the WHO/FAO maximum permissive limit while that of Pb, Ni, Cr and Cu were generally above. This calls for concern, especially in the case of Pb which is highly toxic and of no known biological use, as this could pose a potential risk to residents.Keywords: heavy metals, soil, pollution, EDXRF, Kaduna