Dispersion modelling of emissions from vehicles along the urban section of a major highway

Abstract

Vehicular emissions portend high risk to human health especially to inhabitants of highway environment. However, there is paucity of information on the inventory of air pollutants on Nigerian highways. Therefore, this study aimed at estimating the ground level concentrations of emissions associated with road traffic in the Ogbomoso-section of Ibadan-Ilorin highway. Three sampling locations (Idi-oro, General and Aroje) were selected within the Ogbomoso section of Ibadan-Ilorin highway for this study. Data collections on criteria air pollutants [carbon monoxide (CO), nitrogen monoxide (NO) and sulphur dioxide (SO2)] and total suspended particle (TSP) were made within dry and wet seasons. The results of predicted concentrations of CO, NO, SO2 and TSP ranged between 0.59-352.60, 0.28-213.40, 0.04-33.40 and 0.02-14.20 µg/m3, respectively. All the predicted concentration values of selected pollutants meet-up with the regulatory standards. This study has provided baseline inventory for criteria air pollutants in the Ogbomoso-section of Ibadan-Ilorin highway.