Spatiotemporal patterns in air pollution and sound in Dhaka, Bangladesh

High air pollution and sound in Dhaka pose major health risks, yet limited high-resolution data hinders epidemiologic assessments and interventions. We measured fine particulate matter (PM₂.₅), black carbon (BC), and sound (dBA) at 70 locations across Dhaka during the 2023 dry (Jan-Mar) and wet (Jul-Sep) seasons, with continuous monitoring at 8 fixed sites and short-term sampling at 62 rotating sites (3 days/season). Over 1.7 million minutes of PM_2.5 and 1.2 million minutes of sound were collected, enabling detailed spatial (land use features) and temporal (seasonal, weekly, daily, and diurnal) analyses. Air pollution was four times higher in the dry season, with commercial/industrial areas and transportation corridors having the highest levels, particularly at night. Sound levels varied less temporally, and were highest in transportation corridors, mixed-use areas, and commercial hubs. Air pollution and sound across the city exceeded international guidelines. These findings provide critical evidence to inform targeted policy and interventions.