Spatio-Temporal Variations in Urban Vehicular Emission in Port Harcourt City, Nigeria

vThe increasing high volume of road traffic and congestion is a fundamental issue in Port Harcourt metropolis. The degradation of air quality arising from these is another serious dimension of the problem. This study estimated the emissions of pollutants from vehicles during traffic peak periods within parts of the city of Port Harcourt in Nigeria. It estimated air pollutants, Carbon Monoxide, Nitrogen Oxides, Sulphur Oxides and Hydrocarbons in four sampling points. The level of variation in concentration of emissions between peak and off peak periods of traffic, and between locations was determined. Only traces of SOx were detected at all times and locations, while the concentration of CO detected was higher than the Federal Environmental Protection Agency limits and the recommended municipal (local) standard. This was predominantly in location A. Levels of Hydrocarbon (CxHy) detected varied in space and time, while. NOx was generally above the local and international standards in all the locations during peak traffic period. Though this study did not cover the whole city of Port Harcourt, findings from the four sampling points suggest that the city is under the threat of traffic related pollution and is possibly more susceptible given increasing population influx and vehicular traffic. Improved road network and construction of modern roundabouts could help reduce peak period traffic in the nearest future.Key Words: Air pollution, Road intersection, Peak and off peak, traffic congestion, Vehicular emissio