Real-world and bottom-up methodology for emission inventory development and scenario design in medium-sized cities

Efficient management of air quality requires a comprehensive emission inventory to support decision-making on air quality improvement. This article presents a comprehensive framework for detailed emission inventory development in cities with low-quality basic data, which examines the emission of primary criteria pollutants (CO, NO_x, SO₂, PM_2.5, PM₁₀, and VOC) from mobile sources, residential, commercial, and public services, fuel stations, transport terminals, energy conversion sections, and industries. This research was applied to Tabriz in Northwest Iran, one of the polluted medium-sized cities with a population of 1.77 million. Results show the city daily emission per capita is 569.8 g of CO, 68.6 g of NO_x, 38.6 g of VOC, 17.6 g of SO_x, and 3.7 g of PM. Vehicular emissions accounted for 98% of CO, 91% of VOCs, 61% of NO_x, and 56% of PM; meaning alternative policy strategies in vehicles would reduce emissions rapidly. Fifteen applicable and effective scenarios in transport and one concerning stationary sources were proposed and reduction potential of them was evaluated. Effectiveness of the public transport improvement and replacement of old passenger cars were founded the key scenarios. These two alternatives decrease 14 and 2 tons of SO₂ and 6797 and 2394 tons of NO_x annually with the cost of $99.5 MM and $366.5 MM, respectively. The findings of this study provides the choice of travel method by each citizen is a function of cost, speed, comfort and safety of travel; therefore, all the requirements of any scenarios must be fully considered in the implementation step.