Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Microenvironment Tracker (MicroTrac) model to estimate time-location of individuals for air pollution exposure assessments: model evaluation using smartphone data

Journal of Exposure Science & Environmental Epidemiology volume 33, pages 407–415 (2023)Cite this article

Abstract

Background

A critical aspect of air pollution exposure assessments is determining the time spent in various microenvironments (ME), which can have substantially different pollutant concentrations. We previously developed and evaluated a ME classification model, called Microenvironment Tracker (MicroTrac), to estimate time of day and duration spent in eight MEs (indoors and outdoors at home, work, school; inside vehicles; other locations) based on input data from global positioning system (GPS) loggers.

Objective

In this study, we extended MicroTrac and evaluated the ability of using geolocation data from smartphones to determine the time spent in the MEs.

Method

We performed a panel study, and the MicroTrac estimates based on data from smartphones and GPS loggers were compared to 37 days of diary data across five participants.

Results

The MEs were correctly classified for 98.1% and 98.3% of the time spent by the participants using smartphones and GPS loggers, respectively.

Significance

Our study demonstrates the extended capability of using ubiquitous smartphone data with MicroTrac to help reduce time-location uncertainty in air pollution exposure models for epidemiologic and exposure field studies.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Decision trees of classification model.
Fig. 2: Estimated and diary percentage of day in each ME for each participant.

Similar content being viewed by others

Data availability

The data collected and processed from this study are available from the corresponding author on reasonable request.

References

  1. US Environmental Protection Agency. Integrated science assessment for particulate matter. In EPA600/R-08/139F; Environmental Protection Agency: Washington, DC, USA, 2009.

  2. US Environmental Protection Agency. Integrated science assessment for ozone and related photochemical oxidants. In EPA 600/R-10/076F; Environmental Protection Agency: Washington, DC, USA, 2013.

  3. Zeger SL, Thomas D, Dominici F, Sarnet JM, Schwartz J, Dockery D, et al. Exposure measurement error in time-series studies of air pollution: Concepts and consequences. Environ Health Perspect. 2000;108:419–26.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Sheppard L, Burnett RT, Szpiro AA, Kim SY, Jerrett M, Pope CA III, et al. Confounding and exposure measurement error in air pollution epidemiology. Air Qual Atmos Health. 2012;5:203–16.

    Article  PubMed  Google Scholar 

  5. National Research Council. Exposure Science in the 21st Century: A Vision and a Strategy; The National Academies Press: Washington, DC, USA, 2012.

  6. National Research Council. Research Priorities for Airborne Particulate Matter: I. Immediate Priorities and a Long-Range Research Portfolio; The National Academies Press: Washington, DC, USA, 2004.

  7. National Academies of Sciences, Engineering, and Medicine. Health Risks of Indoor Exposure to Particulate Matter: Workshop Summary; The National Academies Press: Washington, DC, USA, 2016.

  8. National Academies of Sciences, Engineering, and Medicine. Using 21st Century Science to Improve Risk-Related Evaluations; The National Academies Press: Washington, DC, USA, 2017.

  9. Breen MS, Seppanen C, Isakov V, Arunachalam S, Breen M, Samet J, et al. Development of TracMyAir smartphone application for modeling exposures to ambient PM2.5 and Ozone. Int J Environ Res Public Health. 2019. https://doi.org/10.3390/ijerph16183468

    Article  PubMed  PubMed Central  Google Scholar 

  10. Peltier RE, Buckley TJ. Sensor technology: a critical cutting edge of exposure science. J Exp Sci Environ Epidemiol. 2020;30:901–2.

    Article  Google Scholar 

  11. Breen MS, Long T, Schultz B, Crooks J, Breen M, Langstaff J, et al. GPS-based microenvironment tracker (MicroTrac) model to estimate time-location of individuals for air pollution exposure assessments: model evaluation in central North Carolina. J Exp Sci Environ Epidemiol. 2014;24:412–20.

    Article  CAS  Google Scholar 

  12. Donaire-Gonzalez D, Valentín A, de Nazelle A, Ambros A, Carrasco-Turigas G, Seto E, et al. Benefits of mobile phone technology for personal environmental monitoring. JMIR Mhealth Uhealth. 2016;4:e126 https://doi.org/10.2196/mhealth.5771. PMID: 27833069; PMCID: PMC5122720

    Article  PubMed  PubMed Central  Google Scholar 

  13. Asimina S, Chapizanis D, Karakitsios S, Kontoroupis P, Asimakopoulos DN, Maggos T, et al. Assessing and enhancing the utility of low-cost activity and location sensors for exposure studies. Environ Monit Assess. 2018;190:155 https://doi.org/10.1007/s10661-018-6537-2. PMID: 29464404

    Article  CAS  PubMed  Google Scholar 

  14. National Academy of Engineering 2022. Indoor Exposure to Fine Particulate Matter and Practical Mitigation Approaches: Proceedings of a Workshop. Washington, DC: The National Academies Press. https://doi.org/10.17226/26331.

  15. Quinn C, Anderson GB, Magzamen S, Henry CS, Volckens J. Dynamic classification of personal microenvironments using a suite of wearable, low-cost sensors. J Expo Sci Environ Epidemiol. 2020;30:962–70. https://doi.org/10.1038/s41370-019-0198-2. Epub 2020 Jan 14. Erratum in: J Expo Sci Environ Epidemiol. 2020 Mar 5;: PMID: 31937850; PMCID: PMC7358126

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Adams C, Riggs P, Volckens J. Development of a method for personal, spatiotemporal exposure assessment. J Environ Monit. 2009;11:1331–9.

    Article  CAS  PubMed  Google Scholar 

  17. Tandon P, Saelens B, Zhou C, Kerr J, Christakis D. Indoor versus outdoor time in preschoolers at child care. Am J Prev Med. 2013;1:85–88.

    Article  Google Scholar 

  18. McCurdy T, Glen G, Smith L, Lakkadi Y. The national exposure research laboratory’s Consolidated Human Activity Database. J Expo Anal Environ Epidemiol. 2000;10:566–78.

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

We thank Timothy Buckley and David Heist for their review comments and helpful suggestions. All contributions from H. Christopher Frey occurred prior to taking a leave of absence from North Carolina State University for an appointment at the US EPA as the Deputy Assistant Administrator for Science Policy in the Office of Research and Development. Although the manuscript was reviewed by the US EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Author information

Authors and Affiliations

  1. Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA

    Michael S. Breen

  2. Center for Public Health and Environmental Assessment, ORAU/U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA

    Yadong Xu

  3. Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA

    H. Christopher Frey

  4. Center for Public Health and Environment Assessment, ORISE/U.S. Environmental Protection Agency, Chapel Hill, NC, 27514, USA

    Miyuki Breen

  5. Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA

    Vlad Isakov

Authors
  1. Michael S. Breen
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yadong Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. H. Christopher Frey
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Miyuki Breen
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Vlad Isakov
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

MSB was responsible for designing the study, extracting and analysing data, interpreting results, and writing report. YX was responsible for designing the study, extracting and analysing data, interpreting results, and writing report. HCF was responsible for designing the study, extracting and analysing data, interpreting results, writing report. MB was responsible for interpreting results and writing report. VI was responsible for interpreting results and writing report.

Corresponding author

Correspondence to Michael S. Breen.

Ethics declarations

Competing interests

The authors declare no competing interests.

Ethical approval

The procedures involving humans were reviewed and approved by the US EPA Human Subjects Research Review Official.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Breen, M.S., Xu, Y., Christopher Frey, H. et al. Microenvironment Tracker (MicroTrac) model to estimate time-location of individuals for air pollution exposure assessments: model evaluation using smartphone data. J Expo Sci Environ Epidemiol 33, 407–415 (2023). https://doi.org/10.1038/s41370-022-00514-w

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41370-022-00514-w

Keywords

Search

Advanced search

Quick links