Evaluation of Heavy Metal Pollution from Vehicular Exhausts in Soils along a Highway, Southwestern Nigeria

Abstract

The Lagos-Ibadan Expressway is the busiest inter-state route in Nigeria and one of the largest road networks in Africa. It handles more than 250,000 PCUs (Passenger Car Units) daily. Amount of metal emissions being released daily from vehicles plying this road into the environment (air, soil, plant and water) is great! This study evaluated heavy metal composition in soils resulting from exhausts pollution from vehicular movement along Lagos-Ibadan Expressway. A total of two hundred and seventysix soil samples were collected at 5, 15 and 25 m away from the edge of the road. The soil samples were collected with hand auger from the surface to a depth of 10 cm during both dry and wet seasons. Heavy metal concentrations were determined using Atomic Absorption Spectrophotometer (AAS). The heavy metal concentrations found in sampled soil during dry season in mg.kg -1 along the study sites revealed the following,

Trace elements characterization of soils and rocks in Agricultural areas of Labunwa, Near Idanre, Southwestern Nigeria

“…Soils are heterogeneous mixture of organic and inorganic materials that have been formed as a result of the breakdown of biological, chemical and physical materials, which are mobilised by various means of transportation and deposition. According to Abou El-Anwar et al., (2019), a total of twelve (12) elements, comprising Al, Ca, Fe, K, Ti, O, Mg, Mn, Na, Cr, Ni and Si, constitute approximately 99.4% of the total composition of the soil, while other trace elements makes up the remaining. However, the chemistry of the local soils are essentially in uenced by factors such as the underlying rocks (podogenic and lithogenic weathering effects) (Salman 2013), regional and local climatic conditions, topography of the environment, transportation mechanisms among other factors (Gall et al, 2015;Quintero et al, 2017;Li et al, 2019;.…”