A real-time personal PM_2.5 exposure monitoring system and its application for college students

There is a growing need in public health to conduct large-scale epidemiological studies to investigate the health effects of fine particulate matter (PM_2.5) exposure levels. In response to this need, we developed a real-time personal PM_2.5 exposure monitoring system (PEPS: Personal Exposure PM_2.5 System), which is capable of monitoring personal exposure concentration and uploading data in real time. The air quality self-labelling device, specifically customized for the PEPS, can be worn on the body and features functions for real-time data automatic upload, data storage, data export, and localization. This system enables researchers to obtain the big data of personal PM_2.5 exposure concentration at low cost, with minimal manpower and technical requirements. It has been utilized to investigate the personal exposure levels of PM_2.5 among college students in Beijing, China, providing a substantial volume of valuable data for indoor air quality and related epidemiological study. The maximum difference between the monitored daily average exposure concentration and the outdoor concentration was 265 µg/m³, corresponding to a relative error of 1579.5%. The correlation analysis of 11 factors showed that the correlation between exposure concentration and outdoor concentration was as high as 0.66 (p < 0.001), and the correlation between exposure concentration and other certain factors was in the range of [−0.11, −0.03].