Assessment of Brick Kilns’ contribution to the air pollution of Lahore using air quality dispersion modeling

Abstract

Lahore (31.320°N; 74.220°E), Pakistan’s second-largest city with a population of 13 million, is considered among the most polluted cities in the world and the most polluted city in Pakistan. We estimated emissions from one of the major sources (brick kilns) and analysed the corresponding impacts on regional air quality. The distribution of pollutants from the brick kilns in Lahore was calculated via a steady-state model (Sutton’s model) and a dynamic model (Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model version 4). Sutton’s model was used to determine the dispersion of a hypothetical pollutant in the vicinity of multiple brick kilns in a steady state. HYSPLIT was employed to compute the dynamic distribution of pollutant concentrations (24 h) for six pollutants using meteorological data (GDAS) and published emission rates of pollutants. The results for November–February 2021–2022 indicated that only SO₂ exceeded all the WHO, NEQS, and NAAQS standards in the vicinity of the kilns. A comparison of the modeled concentrations from brick kiln emissions in the middle of Lahore with air pollution data for that area indicated significantly higher pollution levels derived from other pollution sources. It was concluded that in addition to SO₂, brick kilns do not contribute significantly to air pollution in a substantial part of the city. However, as the city expands towards the areas where most of the brick kilns are located, this situation will change. These findings underscore the need for strategic urban planning and cleaner kiln technologies to mitigate future air quality impacts.