biostudies-literatureFisher JAIntramural NIH HHS222-227https://www.ebi.ac.uk/biostudies/studies/S-EPMC9815482biostudies-literatureUnknown6(4)The increasing availability of portable air pollution monitoring devices has greatly enhanced the ability to measure personal exposures in real time. However, these devices vary considerably in their cost and specifications, and questions remain as to their reliability and practicality for use in epidemiological investigations. In this field study, three personal PM_2.5 exposure monitors (two nephelometers, one optical particle counter) were compared in an urban setting to assess their feasibility for use in future studies. In total, 3963 1-min measurements were collected over 12 days from locations of several types (e.g., above and below-ground subway stations, sidewalks next to urban traffic, outdoor construction sites) in the Washington, D.C. metropolitan area. Overall, we obsEnvironmental science & technology lettersSources of Variability in Real-time Monitoring Data for Fine Particulate Matter: Comparability of Three Wearable Monitors in an Urban Setting.PMC9815482Z99 CA999999Kim SWong JYYLocke SJAlbert PSJones RRFisher JAFriesen MCKefelegn YfalseSources of Variability in Real-time Monitoring Data for Fine Particulate Matter: Comparability of Three Wearable Monitors in an Urban Setting.The increasing availability of portable air pollution monitoring devices has greatly enhanced the ability to measure personal exposures in real time. However, these devices vary considerably in their cost and specifications, and questions remain as to their reliability and practicality for use in epidemiological investigations. In this field study, three personal PM_2.5 exposure monitors (two nephelometers, one optical particle counter) were compared in an urban setting to assess their feasibility for use in future studies. In total, 3963 1-min measurements were collected over 12 days from locations of several types (e.g., above and below-ground subway stations, sidewalks next to urban traffic, outdoor construction sites) in the Washington, D.C. metropolitan area. Overall, we obs2019-01-01T00:00:00Z2019 Apr2025-04-04T12:37:42.708Z2025-04-04T12:37:42.708ZS-EPMC98154823661871510.1021/acs.estlett.9b00115