title: Using smartphones to collect time-activity data for long-term personal-level air pollution exposure assessment.
abstract: Because of the spatiotemporal variability of people and air pollutants within cities, it is important to account for a person's movements over time when estimating personal air pollution exposure. This study aimed to examine the feasibility of using smartphones to collect personal-level time-activity data. Using Skyhook Wireless's hybrid geolocation module, we developed "Apolux" (Air, Pollution, Exposure), an Android(TM) smartphone application designed to track participants' location in 5-min intervals for 3 months. From 42 participants, we compared Apolux data with contemporaneous data from two self-reported, 24-h time-activity diaries. About three-fourths of measurements were collected within 5 min of each other (mean=74.14%), and 79% of participants reporting constantly powered-on smartphones (n=38) had a daily average data collection frequency of <10 min. Apolux's degree of temporal resolution varied across manufacturers, mobile networks, and the time of day that data collection occurred. The discrepancy between diary points and corresponding Apolux data was 342.3 m (Euclidian distance) and varied across mobile networks. This study's high compliance and feasibility for data collection demonstrates the potential for integrating smartphone-based time-activity data into long-term and large-scale air pollution exposure studies.
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Glasgow
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Carole B
authors.initials: CB
authors.lastname: Rudra
authors.affiliation: Department of Geography, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Eun-Hye
authors.initials: EH
authors.lastname: Yoo
authors.affiliation: Department of Computer Science and Engineering, School of Engineering and Applied Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Murat
authors.initials: M
authors.lastname: Demirbas
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Merriman
authors.affiliation: Department of Computer Science and Engineering, School of Engineering and Applied Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Pramod
authors.initials: P
authors.lastname: Nayak
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Crabtree-Ide
authors.affiliation: Department of Biostatistics, School of Public Health, University of Washington, Seattle, Washington, USA.
authors.forename: Adam A
authors.initials: AA
authors.lastname: Szpiro
authors.affiliation: Department of Computer Science and Engineering, School of Engineering and Applied Sciences, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Atri
authors.initials: A
authors.lastname: Rudra
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.affiliation: Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Lina
authors.initials: L
authors.lastname: Mu
mesh_terms: D000328:Adult; D000397:Air Pollution / Q000032:analysis*; D003625:Data Collection / Q000379:methods* / Q000592:standards*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications / Q000592:standards / Q000706:statistics & numerical data; D009518:New York; D057566:Self Report; D000068997:Smartphone; D013995:Time; D055815:Young Adult