Impact of Traffic Emission on Air Quality in A Developing City of Nigeria

Minna is a developing city that lies between the Sahel and Guinea Savanna regions of Nigeria, and occupies a land area of 490 ha. Its population has increased from 70,000 in 1979 to over 300,000 in 2000. This increase has been attributed to a number of reasons such as nearness to the federal capital city of Nigeria and economic growth. During the period, the number of motor vehicles in the city increased by 400%. Although an increase in the motor vehicles eases the movement of people and goods, it could lead to an increase in traffic emission, which would constitute environmental and health hazards. A micro-scale analysis of the pollutants on a busy road in the city was studied during the dry season. A piston hand gas pump with detector tubes was used to sample CO, NO2, SO2, and CO2. Only traces of NO2 and SO2 were detected. The concentration of CO detected was as high as 15 ppm, which is a little lower than the Federal Environmental Protection Agency limit of 20 ppm, and was attributed to vehicle emission. In addition, the CO2 concentration was as high as 5000 ppm, which is still below the maximum level stipulated by the United States Environmental Protection Agency, but was not due to traffic emission alone. Thus the city is not under the threat of traffic pollution. This finding could serve as base-line information for urban development vis-à-vis traffic management policy in Nigeria