title: Populations potentially exposed to traffic-related air pollution in seven world cities.
abstract: Traffic-related air pollution (TRAP) likely exerts a large burden of disease globally, and in many places, traffic is increasing dramatically. The impact, however, of urban form on the portion of population potentially exposed to TRAP remains poorly understood. In this study, we estimate portions of population potentially exposed to TRAP across seven global cities of various urban forms. Data on population distributions and road networks were collected from the best available sources in each city and from remote sensing analysis. Using spatial mapping techniques, we first overlaid road buffers onto population data to estimate the portions of population potentially exposed for four plausible impact zones. Based on a most likely scenario with impacts from highways up to 300meters and major roadways up to 50meters, we identified that the portions of population potentially exposed for the seven cities ranged from 23 to 96%. High-income North American cities had the lowest potential exposure portions, while those in Europe had the highest. Second, we adjusted exposure zone concentration levels based on a literature suggested multiplier for each city using corresponding background concentrations. Though Beijing and Mexico City did not have the highest portion of population exposure, those in their exposure zones had the highest levels of exposure. For all seven cities, the portion of population potentially exposed was positively correlated with roadway density and, to a lesser extent, with population density. These analyses suggest that urban form may influence the portion of population exposed to TRAP and vehicle emissions and other factors may influence the exposure levels. Greater understanding of urban form and other factors influencing potential exposure to TRAP may help inform interventions that protect public health.
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley 94720-7360, USA. Electronic address: jasonsu@berkeley.edu.
authors.forename: Jason G
authors.initials: JG
authors.lastname: Su
authors.affiliation: Energy and Resources Group, University of California at Berkeley, Berkeley 94720-3050, USA.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Apte
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley 94720-7360, USA.
authors.forename: Jonah
authors.initials: J
authors.lastname: Lipsitt
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley 94720-7360, USA.
authors.forename: Diane A
authors.initials: DA
authors.lastname: Garcia-Gonzales
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley 94720-7360, USA.
authors.forename: Bernardo S
authors.initials: BS
authors.lastname: Beckerman
authors.affiliation: Centre for Environmental Policy, Imperial College London, UK.
authors.forename: Audrey
authors.initials: A
authors.lastname: de Nazelle
authors.affiliation: Environmental Health Department, National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Texcalac-Sangrador
authors.affiliation: Environmental Health Sciences, School of Public Health, University of California at Berkeley, Berkeley 94720-7360, USA; Environmental Health Sciences Department, Fielding School of Public Health, University of California, Los Angeles, 90095-1772, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Jerrett
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D040362:Geographic Information Systems; D006801:Humans; D009589:Nitrogen Oxides / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D011634:Public Health; D014505:Urban Population / Q000706:statistics & numerical data; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Buffer analysis; Building footprint; Geographic Information Systems; Population exposure; Remote sensing; Traffic-related air pollution; Urban form