Comparative evaluation of post-monsoon crossroads air quality variations in major cities of the Greater Dhaka region

Abstract

This study investigates the escalating problem of urban air pollution in Dhaka and its surrounding areas in the post-monsoon period. Using Aeroqual Series 500 air quality monitors, concentrations of NO₂, SO₂, CO₂, CH₄, PM₂.₅, and PM₁₀ were measured at 24 selected sites in Dhaka, Narayanganj, and Gazipur. The findings reveal elevated NO₂ levels in several areas, exceeding the standard threshold of 0.053 ppm, with Gulistan, Mirpur 10, Gabtuli Darus-salam, Farmgate, and Savar showing the highest concentrations. Gulistan also showed a marked SO₂ peak of 0.3 ppm. Areas adjacent to the Buriganga River, specifically Lalbagh and Kadamtuli, were identified as heavily polluted, with strong odour and poor air quality. High concentrations of CH₄ and CO₂ were detected at New Market, Zinda Park, and Jirani Bazar. The average Air Quality Index (AQI) across the sites was 186.8, with a peak of 395 at Joydebpur Rail Station and a low of 110 at Panam City. The study underscores the need for enhanced air quality monitoring and control strategies in Greater Dhaka, highlighting the health risks posed by industrial and vehicular emissions in rapidly urbanizing regions.