The aim of the study was to assess the impact of traffic volume on metal (Cd and Pb) concentration and to evaluate the mobility of the metals using sequential extraction. Particulate dust fall-out and roadside surface soil samples were collected from ten locations along major roads in the Kano metropolis, Nigeria in four seasons: Cool and dry, hot and dry, warm and wet and warm and dry. The samples collected were digested using standard methods and analysed using flame atomic absorption spectrophotometer. The results of metal inter-relation analysis on both samples revealed positive correlations for Cd and traffic volume and the metals for the studied seasons while positive correlation was found for Pb during warm and wet and warm and dry seasons. Positive correlation between the metals (Cd and Pb) and traffic confirmed the fact that automobiles are major source of the presence of these metals in the roadside environment. Also, the results showed that the concentrations in the mobile phase (water soluble, exchangeable and carbonate bound fractions) were generally high for Cd (29.49-92.7%) and Pb (26-76.4%) with the highest obtained during warm and wet and warm and dry seasons. This suggests potential toxicity to residential and food vendors adjacent to major roads in Kano metropolis. These could be direct or indirect pathways of metal in humans.
O.J. Okunola, A. Uzairu, C.E. Gimba and J.A. Kagbu, 2011. Metal Inter-relationship and its Mobility in Samples Collected along Roadside Corridors of Kano Metropolis, Nigeria. Research Journal of Environmental Toxicology, 5: 336-347.