Comparison of PM2.5 trends and source factors in urban and rural locations in Bangladesh

Air pollution remains a critical environmental and public health concern, particularly in developing countries like Bangladesh. Although urban air pollution has received significant attention, rural areas also experience high PM2.5 concentrations. In this study, a low-cost sensor (LCS) network was deployed across five locations: Dhaka, Rajshahi, Panchagarh, Netrokona, and Bhola from April 2022 to September 2023 to assess local and regional sources of PM2.5. A Generalized Additive Model (GAM) was applied to analyze the influence of meteorology and source contributions on observed PM2.5 concentrations. The highest PM2.5 levels were recorded in Netrokona (212.81 ± 64.5 μgm⁻³), followed by Panchagarh (128.6 ± 71.7 μgm⁻³), Rajshahi (110.4 ± 48.5 μgm⁻³), Dhaka (105.1 ± 55.7 μgm⁻³) and Bhola (82.2 ± 36.2 μgm⁻³). A consistent diurnal pattern was observed across all sites, characterized by two peaks in the morning and evening. GAM analysis revealed that the boundary layer height had the lowest influence in Bhola and Panchagarh, while Dhaka exhibited the highest contribution. The contribution of long-range transport was found uniform at all the sites. The Trajectory Cluster Concentration Impact (TCCI) showed that the Indo-Gangetic Plain (IGP) is responsible for the enhancement of 50 μgm⁻³ at all the sites. However, wind transported from the Bay of Bengal associates PM2.5 reduction of 20–40 μgm⁻³. Impacts of local winds on the PM2.5 concentrations in the GAM simulations suggested that winds from the northwest are associated with higher PM2.5. These findings emphasize the need for comprehensive air quality management strategies that extend beyond major urban centers to include rural and semi-urban areas.

Duke Scholars

Author Michael Howard Bergin Civil and Environmental Engineering