We determined how, when, and where children are exposed to particulate air pollution (PAP) in Kathmandu and Bandung in order to develop targeted exposure reduction practices. We used real-time PurpleAir II sensors (Purple Air, USA) to monitor both PM2.5 personal exposures (mobile measurements with added power packs and GPS units) and ambient PAP (static measurements), outside and inside the home and school environment. Sensor calibration to local conditions was conducted by co-location experiments at governmental ambient PM monitoring stations. Thirty children were recruited in each city to participate in WP1.

1) Exposure measurements: Each child’s personal exposure was monitored consecutively over a week, to understand exposure during routine activities. Time-stamped PM2.5 concentrations were matched with GPS data and time-activity questionnaires to apportion exposure to different places/activities (microenvironments). 

2) Ambient PM2.5 measurements: Monitoring was conducted outside, at the children’s schools, allowing us to determine indoor and outdoor PAP concentrations. Official air quality data were also obtained to assess air quality variations across seasons and beyond the studied cities.

3) Questionnaires and field observations: Data were gathered on contextual issues, such as proximity to pollutant sources, and behaviours which affect the measured exposures. Information about the home and school building construction/design were also gathered, as were details of any PAP mitigation measures already being used.

Data from WP1 informed the HIA (WP3) and uptake activities (WP7).

Results

An infographic for children gives the results for Nepal and Indonesia: http://face-up-consortium.webspace.durham.ac.uk/wp-content/uploads/2026/08/WP1-infographic-FINAL_English.pptx

The published findings of this project are available at: https://doi.org/10.1088/2752-5309/ae8050