Urban air pollutant mapping and tracing using multi-points in situ measurements combined with clustering and trajectory analysis

Air pollution poses significant risks, particularly in developing countries where rapid urbanization exacerbates pollutant emissions. These pollutants impact local populations and contribute to global air quality challenges through long-range transport. Despite numerous studies, comprehensive data on pollutant characteristic in urban areas remain limited by the availability of air quality monitoring stations in emerging urban regions, especially at developing countries. This study addresses these gaps by employing a novel approach that combines multi-points in situ air quality measurements with clustering and back trajectory analysis to map and trace pollution sources across diverse urban environments. The use of low-cost and mid-cost portable instruments allows for resource-efficient data collection, enhancing the ability to identify pollution hotspots without requiring extensive infrastructure. The analysis revealed two distinct pollutant clusters: aerosol pollutants dominated in residential areas, while gaseous pollutants were more prevalent near traffic-heavy and construction areas. Although low-cost sensors have limited capabilities and should not be used for regulatory purposes, this methodology provides a scalable complementary addition to regular air quality monitoring and offers valuable insights into pollution source attribution, particularly in developing countries where resources for environmental monitoring are limited.