Imperial College London

DrAudreyde Nazelle

Faculty of Natural SciencesCentre for Environmental Policy

Senior Lecturer



+44 (0)20 7594 7319anazelle Website




20416 Prince's GardensSouth Kensington Campus






BibTex format

author = {Donaire-Gonzalez, D and Valentin, A and de, Nazelle A and Ambros, A and Carrasco-Turigas, G and Seto, E and Jerrett, M and Nieuwenhuijsen, MJ},
doi = {10.2196/mhealth.5771},
journal = {JMIR mHealth and uHealth},
title = {Benefits of Mobile Phone Technology for Personal Environmental Monitoring},
url = {},
volume = {4},
year = {2016}

RIS format (EndNote, RefMan)

AB - Background: Tracking individuals in environmental epidemiological studies using novel mobile phone technologies can provide valuable information on geolocation and physical activity, which will improve our understanding of environmental exposures.Objective: The objective of this study was to assess the performance of one of the least expensive mobile phones on the market to track people's travel-activity pattern.Methods: Adults living and working in Barcelona (72/162 bicycle commuters) carried simultaneously a mobile phone and a Global Positioning System (GPS) tracker and filled in a travel-activity diary (TAD) for 1 week (N=162). The CalFit app for mobile phones was used to log participants’ geographical location and physical activity. The geographical location data were assigned to different microenvironments (home, work or school, in transit, others) with a newly developed spatiotemporal map-matching algorithm. The tracking performance of the mobile phones was compared with that of the GPS trackers using chi-square test and Kruskal-Wallis rank sum test. The minute agreement across all microenvironments between the TAD and the algorithm was compared using the Gwet agreement coefficient (AC1).Results: The mobile phone acquired locations for 905 (29.2%) more trips reported in travel diaries than the GPS tracker (P<.001) and had a median accuracy of 25 m. Subjects spent on average 57.9%, 19.9%, 9.0%, and 13.2% of time at home, work, in transit, and other places, respectively, according to the TAD and 57.5%, 18.8%, 11.6%, and 12.1%, respectively, according to the map-matching algorithm. The overall minute agreement between both methods was high (AC1 .811, 95% CI .810-.812).Conclusions: The use of mobile phones running the CalFit app provides better information on which microenvironments people spend their time in than previous approaches based only on GPS trackers. The improvements of mobile phone technology in microenvironment determination are because the m
AU - Donaire-Gonzalez,D
AU - Valentin,A
AU - de,Nazelle A
AU - Ambros,A
AU - Carrasco-Turigas,G
AU - Seto,E
AU - Jerrett,M
AU - Nieuwenhuijsen,MJ
DO - 10.2196/mhealth.5771
PY - 2016///
SN - 2291-5222
TI - Benefits of Mobile Phone Technology for Personal Environmental Monitoring
T2 - JMIR mHealth and uHealth
UR -
UR -
VL - 4
ER -