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:

The impact of daily mobility on exposure to traffic-related air pollution and health effect estimates

Abstract

Epidemiological studies of traffic-related air pollution typically estimate exposures at residential locations only; however, if study subjects spend time away from home, exposure measurement error, and therefore bias, may be introduced into epidemiological analyses. For two study areas (Vancouver, British Columbia, and Southern California), we use paired residence- and mobility-based estimates of individual exposure to ambient nitrogen dioxide, and apply error theory to calculate bias for scenarios when mobility is not considered. In Vancouver, the mean bias was 0.84 (range: 0.79–0.89; SD: 0.01), indicating potential bias of an effect estimate toward the null by 16% when using residence-based exposure estimates. Bias was more strongly negative (mean: 0.70, range: 0.63–0.77, SD: 0.02) when the underlying pollution estimates had higher spatial variation (land-use regression versus monitor interpolation). In Southern California, bias was seen to become more strongly negative with increasing time and distance spent away from home (e.g., 0.99 for 0–2 h spent at least 10 km away, 0.66 for ≥10 h spent at least 40 km away). Our results suggest that ignoring daily mobility patterns can contribute to bias toward the null hypothesis in epidemiological studies using individual-level exposure estimates.

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

Access options

Buy this article

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

Figure 1
Figure 2
Figure 3

Similar content being viewed by others

References

  • Armstrong B.G. The effects of measurement errors on relative risk regressions. Am J Epidemiol 1990: 132 (6): 1176–1184.

    Article  CAS  Google Scholar 

  • Armstrong B.G. Effect of measurement error on epidemiological studies of environmental and occupational exposures. Occup Environ Med 1998: 55 (10): 651–656.

    Article  CAS  Google Scholar 

  • Berhane K., Gauderman W.J., Stram D.O., and Thomas D.C. Statistical issues in studies of the long-term effects of air pollution: the Southern California Children's Health Study. Stat Sci 2004: 19 (3): 414–434.

    Article  Google Scholar 

  • Gilliland F., Avol E., Kinney P., Jerrett M., Dvonch T., and Lurmann F., et al. Air pollution exposure assessment for epidemiologic studies of pregnant women and children: lessons learned from the Centers for Children's Environmental Health and Disease Prevention Research. Environ Health Perspect 2005: 113 (10): 1447–1454.

    Article  CAS  Google Scholar 

  • Henderson S.B., Beckerman B., Jerrett M., and Brauer M. Application of land use regression to estimate long-term concentrations of traffic-related nitrogen oxides and fine particulate matter. Environ Sci Technol 2007: 41 (7): 2422–2428.

    Article  CAS  Google Scholar 

  • Hoek G., Beelen R., de Hoogh K., Vienneau D., Gulliver J., and Fischer P., et al. A review of land-use regression models to assess spatial variation of outdoor air pollution. Atmos Environ 2008: 42 (33): 7561–7578.

    Article  CAS  Google Scholar 

  • Jerrett M., Burnett R.T., Ma R.J., Pope C.A., Krewski D., and Newbold K.B., et al. Spatial analysis of air pollution and mortality in Los Angeles. Epidemiology 2005: 16 (6): 727–736.

    Article  Google Scholar 

  • Kousa A., Monn C., Rotko T., Alm S., Oglesby L., and Jantunen M.J. Personal exposures to NO2 in the EXPOLIS-study: relation to residential indoor, outdoor and workplace concentrations in Basel, Helsinki and Prague. Atmos Environ 2001: 35 (20): 3405–3412.

    Article  CAS  Google Scholar 

  • Marshall J.D. Environmental inequality: air pollution exposures in California's South Coast Air Basin. Atmos Environ 2008: 42 (21): 5499–5503.

    Article  CAS  Google Scholar 

  • Marshall J.D., Granvold P.W., Hoats A.S., McKone T.E., Deakin E., and Nazaroff W.W. Inhalation intake of ambient air pollution in California's South Coast Air Basin. Atmos Environ 2006: 40 (23): 4381–4392.

    Article  CAS  Google Scholar 

  • Miller K.A., Siscovick D.S., Sheppard L., Shepherd K., Sullivan J.H., and Anderson G.L., et al. Long-term exposure to air pollution and incidence of cardiovascular events in women. N Engl J Med 2007: 356 (5): 447–458.

    Article  CAS  Google Scholar 

  • Navidi W., and Lurmann F. Measurement error in air-pollution exposure assessment. J Expo Anal Environ Epidemiol 1995: 5 (2): 111–124.

    CAS  PubMed  Google Scholar 

  • Nethery E., Leckie S.E., Teschke K., and Brauer M. From measures to models: an evaluation of air pollution exposure assessment for epidemiological studies of pregnant women. Occup Environ Med 2008: 65 (9): 579–586.

    Article  CAS  Google Scholar 

  • Nordling E., Berglind N., Melen E., Emenius G., Hallberg J., and Nyberg F., et al. Traffic-related air pollution and childhood respiratory symptoms, function and allergies. Epidemiology 2008: 19 (3): 401–408.

    Article  Google Scholar 

  • Quackenboss J.J., Spengler J.D., Kanarek M.S., Letz R., and Duffy C.P. Personal exposure to nitrogen-dioxide — relationship to indoor outdoor air-quality and activity patterns. Environ Sci Technol 1986: 20 (8): 775–783.

    Article  CAS  Google Scholar 

  • SCAG — Southern California Association of Government. Year 2000 Post-Census Regional Travel Survey, Final Report of Survey Results, Southern California Association of Government, Austin, TX, 2003.

  • Setton E.M., Keller C.P., Cloutier-Fisher D., and Hystad P.W. Spatial variations in estimated chronic exposure to traffic-related air pollution in working populations: a simulation. Int J Health Geogr 2008: 7.

    Article  Google Scholar 

  • Sheppard L., Slaughter J.C., Schildcrout J., Liu L.J.S., and Lumley T. Exposure and measurement contributions to estimates of acute air pollution effects. J Expo Anal Environ Epidemiol 2005: 15 (4): 366–376.

    Article  CAS  Google Scholar 

  • Strand M., Vedal S., Rodes C., Dutton S.J., Gelfand E.W., and Rabinovitch N. Estimating effects of ambient PM2.5 exposure on health using PM2.5 component measurements and regression calibration (vol 16, pg 30, 2006). J Expo Sci Environ Epidemiol 2006: 16 (5): 471.

    Article  CAS  Google Scholar 

  • Van Roosbroeck S., Li R.F., Hoek G., Lebret E., Brunekreef B., and Spiegelman D. Traffic-related outdoor air pollution and respiratory symptoms in children - the impact of adjustment for exposure measurement error. Epidemiology 2008: 19 (3): 409–416.

    Article  Google Scholar 

  • Wacholder S. When measurement errors correlate with truth — surprising effects of nondifferential misclassification. Epidemiology 1995: 6 (2): 157–161.

    Article  CAS  Google Scholar 

  • Wilson J.G., Kingham S., Pearce J., and Sturman A.P. A review of intraurban variations in particulate air pollution: implications for epidemiological research. Atmos Environ 2005: 39 (34): 6444–6462.

    Article  CAS  Google Scholar 

  • Zeger S.L., Thomas D., Dominici F., Samet J.M., Schwartz J., and Dockery D., et al. Exposure measurement error in time-series studies of air pollution: concepts and consequences. Environ Health Perspect 2000: 108 (5): 419–426.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank Dr. Ben Armstrong for his guidance during the conceptual development of this paper. Partial funding was provided by Health Canada and by a grant from the US Environmental Protection Agency's Science to Achieve Results (STAR) program. Although the research described in the article has been funded in part by the US Environmental Protection Agency's STAR program through Grant RD-83362401-0, it has not been subjected to any EPA review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Eleanor Setton.

Ethics declarations

Competing interests

The authors declare no conflict of interest.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Setton, E., Marshall, J., Brauer, M. et al. The impact of daily mobility on exposure to traffic-related air pollution and health effect estimates. J Expo Sci Environ Epidemiol 21, 42–48 (2011). https://doi.org/10.1038/jes.2010.14

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/jes.2010.14

Keywords

Search

Quick links