Ambient Air Pollutions along a Major South-Western Nigerian Road

Abstract

This study investigated the air pollutants in the ambient air of a typical intercity highway in Nigeria. This was to assess the effect of vehicular emission on air quality along the highway. The results showed that NOX concentrations ranged from 9.9±3.2 to 33.8±3.3 µg/m3 during the wet season and 19.0±1.2 to 35.4±2.3 µg/m3 during the dry season. Sulfur dioxide measured along this highway ranged from 49.7±38.1 to 219±18.1 µg/m3 during the wet season while dry season concentration ranged from 89.1±20.9 to 225.4±57.9 µg/m3. The TSP during the wet season ranged from 54.4±25.6 to 126.8±25.6 µg/m3. These values were below the limits of 250 mg/m3 set by FMEnv., and 150-230 mg/m3 by WHO. However, the TSP measured during the dry season ranged from 85.9±44.6 to 277.8±213.5 µg/m3. The average correlations between NOX, SO2, and TSP measured during wet and dry seasons and the traffic density were 0.7, 0.6 and 0.7, respectively. Air pollution along the Nigerian highway is highly linked to vehicular activities.