title: Improving estimates of air pollution exposure through ubiquitous sensing technologies.
abstract: Traditional methods of exposure assessment in epidemiological studies often fail to integrate important information on activity patterns, which may lead to bias, loss of statistical power, or both in health effects estimates. Novel sensing technologies integrated with mobile phones offer potential to reduce exposure measurement error. We sought to demonstrate the usability and relevance of the CalFit smartphone technology to track person-level time, geographic location, and physical activity patterns for improved air pollution exposure assessment. We deployed CalFit-equipped smartphones in a free-living population of 36 subjects in Barcelona, Spain. Information obtained on physical activity and geographic location was linked to space-time air pollution mapping. We found that information from CalFit could substantially alter exposure estimates. For instance, on average travel activities accounted for 6% of people's time and 24% of their daily inhaled NO2. Due to the large number of mobile phone users, this technology potentially provides an unobtrusive means of enhancing epidemiologic exposure data at low cost.
authors: Centre for Environmental Policy, Imperial College London, London SW7 1NA, UK. anazelle@imperial.ac.uk
authors: Audrey
authors: A
authors: de Nazelle
authors: Edmund
authors: E
authors: Seto
authors: David
authors: D
authors: Donaire-Gonzalez
authors: Michelle
authors: M
authors: Mendez
authors: Jaume
authors: J
authors: Matamala
authors: Mark J
authors: MJ
authors: Nieuwenhuijsen
authors: Michael
authors: M
authors: Jerrett
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000397:Air Pollution / Q000706:statistics & numerical data*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D008297:Male; D013030:Spain