Effect of Highway Aerosol on Gmelina arborea and Soil Around Oluwa Forest Reserve 02

Air pollution is one of the universal forest reserve bane that demolishes the bark, leaves, and plant root. The aim of the study was to determine the effects of road proximity on elements accumulation in Gmelina arborea and soil samples. The leaves were dried on oven at around 75 degrees C and blended with electric blender to powder. The dried soil samples and the pulverized dried leaves were pelletized for the determination of metal concentration using particle induced X-ray emission (PIXE). The concentration of the elements in soil and leaves obtained in this study was higher than the limit of the International Atomic Energy Agency (IAEA) and the WHO. The bio-availability values for the elements except for Aluminum was higher than the regulatory limit. The mean soil concentrations of Al, Na, P, and K were greater than the IAEA maximum. The trend of the elemental concentrations in leaves was Pb < Cd < Sn < Sr < Zn < P < Ag < Cr < Al < Mn < Cu < Mg < K < Si < Ca < Ti < Fe while the trend in soil was Pb < Zn < Sn < Cu < Ag < Cd < Cl < P < Mn < Na < Ca < Zr < K < Mg < Al < Ti < Si < Fe. The study provided information on the best distance to keep from the highway for the establishment of healthy flora species.