Metro Commuter Exposures to Particulate Air Pollution and PM2.5-Associated Elements in Three Canadian Cities: The Urban Transportation Exposure Study.

System-representative commuter air pollution exposure data were collected for the metro systems of Toronto, Montreal, and Vancouver, Canada. Pollutants measured included PM2.5 (PM = particulate matter), PM10, ultrafine particles, black carbon, and the elemental composition of PM2.5. Sampling over three weeks was conducted in summer and winter for each city and covered each system on a daily basis. Mixed-effect linear regression models were used to identify system features related to particulate exposures. Ambient levels of PM2.5 and its elemental components were compared to those of the metro in each city. A microenvironmental exposure model was used to estimate the contribution of a 70 min metro commute to daily mean exposure to PM2.5 elemental and mass concentrations. Time spent in the metro was estimated to contribute the majority of daily exposure to several metallic elements of PM2.5 and 21.2%, 11.3% and 11.5% of daily PM2.5 exposure in Toronto, Montreal, and Vancouver, respectively. Findings suggest that particle air pollutant levels in Canadian metros are substantially impacted by the systems themselves, are highly enriched in steel-based elements, and can contribute a large portion of PM2.5 and its elemental components to a metro commuter's daily exposure.

[1]  G D Pfeifer,et al.  Personal exposures to airborne metals in London taxi drivers and office workers in 1995 and 1996. , 1999, The Science of the total environment.

[2]  Marika Egyed,et al.  Effects of Age, Season, Gender and Urban-Rural Status on Time-Activity: Canadian Human Activity Pattern Survey 2 (CHAPS 2) , 2014, International journal of environmental research and public health.

[3]  Chi Nyon Kim,et al.  Spatial distribution of particulate matter (PM10 and PM2.5) in Seoul Metropolitan Subway stations. , 2008, Journal of hazardous materials.

[4]  M. Minguillón,et al.  Factors controlling air quality in different European subway systems. , 2016, Environmental research.

[5]  Timo Mäkelä,et al.  The concentrations and composition of and exposure to fine particles (PM2.5) in the Helsinki subway system , 2005 .

[6]  Dong-Uk Park,et al.  Characteristics of PM10, PM2.5, CO2 and CO monitored in interiors and platforms of subway train in Seoul, Korea. , 2008, Environment international.

[7]  Luca Rossi,et al.  Diffuse release of environmental hazards by railways , 2008 .

[8]  Richard de Dear,et al.  Exposure to ultrafine particles and PM2.5 in four Sydney transport modes , 2010 .

[9]  Scott Weichenthal,et al.  Determinants of ultrafine particle exposures in transportation environments: findings of an 8-month survey conducted in Montréal, Canada , 2008, Journal of Exposure Science and Environmental Epidemiology.

[10]  Mark J. Nieuwenhuijsen,et al.  Fine particulate matter and carbon monoxide exposure concentrations in urban street transport microenvironments , 2007 .

[11]  R. Colvile,et al.  Levels of particulate air pollution, its elemental composition, determinants and health effects in metro systems , 2007 .

[12]  Ernest Weingartner,et al.  Iron, manganese and copper emitted by cargo and passenger trains in Zürich (Switzerland): Size-segregated mass concentrations in ambient air , 2007 .

[13]  George D. Thurston,et al.  Black Carbon and Particulate Matter (PM2.5) Concentrations in New York City’s Subway Stations , 2014, Environmental science & technology.

[14]  K. Aronson,et al.  Commuting behaviors and exposure to air pollution in Montreal, Canada. , 2015, The Science of the total environment.

[15]  Vânia Martins,et al.  Exposure to airborne particulate matter in the subway system. , 2015, The Science of the total environment.

[16]  Robert Gehrig,et al.  Particle emissions of a railway line determined by detailed single particle analysis , 2006 .

[17]  Duckshin Park,et al.  Source identification of PM10 pollution in subway passenger cabins using positive matrix factorization , 2012 .

[18]  Vânia Martins,et al.  Origin of inorganic and organic components of PM2.5 in subway stations of Barcelona, Spain. , 2016, Environmental pollution.

[19]  Yifang Zhu,et al.  Seasonal Trends of Concentration and Size Distribution of Ultrafine Particles Near Major Highways in Los Angeles Special Issue of Aerosol Science and Technology on Findings from the Fine Particulate Matter Supersites Program , 2004 .

[20]  Ernest Weingartner,et al.  Fine and ultrafine particles in the Zürich (Switzerland) area measured with a mobile laboratory: an assessment of the seasonal and regional variation throughout a year , 2003 .

[21]  Duckshin Park,et al.  Identification of the sources of PM10 in a subway tunnel using positive matrix factorization , 2014, Journal of the Air & Waste Management Association.

[22]  Mar Viana,et al.  Assessment of personal exposure to particulate air pollution during commuting in European cities--recommendations and policy implications. , 2014, The Science of the total environment.

[23]  S. Weichenthal,et al.  In-vehicle exposures to particulate air pollution in Canadian metropolitan areas: the urban transportation exposure study. , 2015, Environmental science & technology.

[24]  Cheol-Heon Jeong,et al.  Five-year roadside measurements of ultrafine particles in a major Canadian city , 2012 .

[25]  I. Rivas,et al.  Urban air quality comparison for bus, tram, subway and pedestrian commutes in Barcelona. , 2015, Environmental research.

[26]  P. Koutrakis,et al.  Development and Laboratory Performance Evaluation of a Personal Multipollutant Sampler for Simultaneous Measurements of Particulate and Gaseous Pollutants , 2001 .

[27]  Anders Ekberg,et al.  Emissions of particulate matters from railways – Emission factors and condition monitoring , 2010 .

[28]  Windsor, Ontario Exposure Assessment Study: Design and Methods Validation of Personal, Indoor, and Outdoor Air Pollution Monitoring , 2011, Journal of the Air & Waste Management Association.

[29]  Sonja N Sax,et al.  Elevated airborne exposures of teenagers to manganese, chromium, and iron from steel dust and New York City's subway system. , 2004, Environmental science & technology.

[30]  M. Minguillón,et al.  A new look at inhalable metalliferous airborne particles on rail subway platforms. , 2015, The Science of the total environment.

[31]  C. Sioutas,et al.  Particulate matter (PM) concentrations in underground and ground-level rail systems of the Los Angeles Metro , 2011 .

[32]  Pasi Aalto,et al.  The particle detection efficiency of the TSI-3007 condensation particle counter , 2002 .

[33]  Matthew Loxham,et al.  Physicochemical Characterization of Airborne Particulate Matter at a Mainline Underground Railway Station , 2013, Environmental science & technology.