Assessment of concentration and spatial variation of air pollution in Zaria metropolis, Nigeria

Abstract

The emission of air pollutants has led to numerous air quality issues in cities and a major factor in this is increasing population and growth in road traffic. This study assessed concentration of carbon monoxide (CO), Nitrogen dioxide (NO2), and Sulfur dioxide (SO2) in relation to traffic density on ambient air quality in Zaria metropolis. The Gray Wolf sensing solutions with the model number (203) 402-0477 was used for monitoring the concentration of the three (3) gases at the selected motorways in Zaria metropolis, and a vehicle count was conducted in the morning, afternoon, and evening time. The results indicated that the concentration levels of CO, NO₂, and SO₂ detected varied in space and time. The concentration were generally high and above the National Ambient Air Quality (NAAQ) permissible limits during traffic peak periods, especially during the evening period. The level of pollutants across all the sampling points also increases with traffic volume. The study established strong statistical evidence that traffic volume influences the pollutants concentrations at all sampling points. The study recommended development of road networks and construction of modern roundabouts and bridges in Zaria Metropolis to ease traffic flow and reduce the concentration of air pollutants to acceptable limits.