RISK ASSESSMENT OF HEAVY METALS LEVEL IN SOILS AND FOOD CROPS AROUND A CERAMICS COMPANY IN AJAOKUTA, KOGI STATE, NORTH CENTRAL NIGERIA

Abstract

Some metals associated with ceramics emission were determined in agricultural soil and leaves of maize and cassava around the vicinity of a major ceramic company. These metals are released during production process into the environment. Soil samples were collected at depth of 0-15 cm and 15-30 cm at certain distance (100 m, 200 m, 300 m and 400 m). Leaves of maize and cassava were collected around the soil samples area. Samples were collected to make a composite of 24 for both soil and leaves of crops respectively. Soil and plant digest were analysed by atomic absorption spectrometry. Result showed the range of metal (mg/kg) in topsoil Cd (1.00-8.25), Mn (3.75-62.0), Ni (11.0-46.3) and Pb (5.50-101.2). Corresponding value in subsoil was not significantly different (p>0.05). The concentration of Mn in leaves of cassava is of concern especially if it will be used in the formulation of animal feed. The geo-accumulation (Igeo) of metals in soil revealed that the soil is slightly polluted. Uptake of metals into crops was low except Mn in cassava leaves. A health risk index (HRI) value for the food crops was <1 except for Mn were HRI>1 for cassava. Overall food crop consumption of the study area does not pose a potential threat at the moment.