Spatial distribution and diurnal variation of particulate matters and gaseous air pollutants of Dhaka city, Bangladesh

Abstract Air Pollution poses significant environmental and health challenges, particularly in South Asia, including Bangladesh, over the past two decades. Therefore, this study examines the spatiotemporal variability of aerosols (PM 2.5 , PM 10 ) and gaseous pollutants (CO, CO 2 , CH 4 , NO 2 , and SO 2 ) during December 2021 and January 2022 in Dhaka (a major city in Bangladesh) using ground-based Aeroqual S500 data. Additionally, Pearson correlation, Principal Component Analysis (PCA), and Hierarchy Cluster Analysis (HCA) were conducted to identify the main sources of aerosols and gaseous pollutants. From the spatiotemporal study, the highest pollutant concentrations were observed in Gulisthan (CO: 2.7 ppm), Abdullahpur (NO 2 : 6.1 ppm, PM 10 : 390 µg/m 3 ), Gabtoli (PM 2.5 :232 µg/m 3 ). Statistical analyses including Pearson correlations, PCA and HCA indicate that motor vehicle emissions, road traffic dust, and industrial activities are the primary sources of air pollution in Dhaka City. Calculated Air Quality Index (AQI) values ranged from 193 to 282 indicating unhealthy air quality levels. This study highlights the strong connection between poor air quality and health impacts including respiratory and cardiovascular illness exacerbated by elevated levels of PM 2.5 and PM 10 in Dhaka City, showing the severity of air pollution there. These findings underscore the urgent need for mitigation measures and effective air pollution control strategies. Policymakers, urban planners, and environmental agencies can leverage these insights to prioritize air pollution control measures, protecting public health and minimizing ecosystem damage. By addressing the root causes of air pollution, Dhaka can significantly enhance the well-being of its residents and reduce the burden of air pollution-related diseases.