Auto-Vehicle Operation and Emission Assessment Tested under Ambient Conditions within Minna, Nigeria

Heightened levels of auto-vehicle emissions are deemed to be one of the significant contributors to environmental air pollution and health hazards for road users. The frequent use of various auto-vehicles for commuting purposes involving people and freight, especially within urban centres proliferates this concern. This study deployed secondary data obtained from the computerized vehicle inspection office in Minna, via the use of an exhaust gas testing device (F 5000 – 5 series) to examine idle emission data from the exhaust pipes of auto-vehicles. Emission data involving three main pollutants namely, carbon monoxide (CO), nitrous oxide (NO), and sulfur dioxide (SO2) was collected from 385 vehicles inspected at the computerized vehicle inspection office in Minna. For reliability and credibility, purposive sampling involving valid vehicular records was used for data analysis. Empirical findings from the gas analyzer indicated that CO and NO were the major pollutants with significant isolated concentrations among auto-vehicles. Their peak values observed were 19 ppm and 0.24 ppm respectively, for mass transit buses and heavy-duty vehicles. Results from the Binary Logistic Model (BLM) indicated that the frequency of vehicle maintenance through regular oil change (????1) as a predictor, was a significant factor in determining emission levels for tested auto-vehicles (???? < 0.05). The likelihood ratio, Exp(B) for ????1 compared to other predictors was 2.904.