Spatial Distribution of Cadmium and Lead (Cd and Pb) Along Owerri – Orlu Road Highway in Imo State, Nigeria

Vehicular emissions have been found to constitute the major sources of soil and air pollution. This study attempts to investigate the spatial influence of vehicular emissions on the accumulation of heavy metals (cadmium and lead) in some of the roadside soil of Owerri – Orlu road in Imo state. Four locations were selected on the basis of their high concentration of vehicular traffic in Owerri – Orlu. They include Y- Junction, Umuaka, Okwudor and Amaifeke. The concentrations of two heavy metals (Cadium and Lead) in the soil samples were determined calorimetrically using atomic absorption spectrophotometer (AAS). The heavy metal (Cd and Pb) results obtained indicate that the metals from the four sampled sites showed high concentration of Cd far above the soil permissible limit (3 mg kg-1) on all the sampled sites which farther increase away from the road. The concentration of the Pb was found to be lower than the soil permissible limit (50 mg kg-1). Pb despite been lower than the permissible limit, also follows the same trend as in Cd. A factor strongly controlled by the soil properties especially soil texture which are mainly of high sand particles (86.3 to 91%). Correlation results showed that soil properties heavily influence the amount and the movement of these metals along the road and farther away from the road. Although Pb concentrations were below permissible soil limit long time exposure may pose health hazards. The enhancement of fuel quality and the adoption of emission standards to mitigate the impact of vehicular emissions on human health should be adopted.