title: Modeling spatial variations of black carbon particles in an urban highway-building environment.
abstract: Highway-building environments are prevalent in metropolitan areas. This paper presents our findings in investigating pollutant transport in a highway-building environment by combing field measurement and numerical simulations. We employ and improve the Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model to simulate the spatial variations of black carbon (BC) concentrations near highway I-87 and an urban school in the South Bronx, New York. The results of CTAG simulations are evaluated against and agree adequately with the measurements of wind speed, wind directions, and BC concentrations. Our analysis suggests that the BC concentration at the measurement point of the urban school could decrease by 43-54% if roadside buildings were absent. Furthermore, we characterize two generalized conditions in a highway-building environment, i.e., highway-building canyon and highway viaduct-building. The former refers to the canyon between solid highway embankment and roadside buildings, where the spatial profiles of BC depend on the equivalent canyon aspect ratio and flow recirculation. The latter refers to the area between a highway viaduct (i.e., elevated highway with open space underneath) and roadside buildings, where strong flow recirculation is absent and the spatial profiles of BC are determined by the relative heights of the highway and buildings. The two configurations may occur at different locations or in the same location with different wind directions when highway geometry is complex. Our study demonstrates the importance of incorporating highway-building interaction into the assessment of human exposure to near-road air pollution. It also calls for active roles of building and highway designs in mitigating near-road exposure of urban population.
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, United States.
authors.forename: Zheming
authors.initials: Z
authors.lastname: Tong
authors.forename: Yan Jason
authors.initials: YJ
authors.lastname: Wang
authors.forename: Molini
authors.initials: M
authors.lastname: Patel
authors.forename: Patrick
authors.initials: P
authors.lastname: Kinney
authors.forename: Steven
authors.initials: S
authors.lastname: Chrillrud
authors.forename: K Max
authors.initials: KM
authors.lastname: Zhang
mesh_terms: D002244:Carbon / Q000032:analysis*; D002947:Cities; D003198:Computer Simulation; D003252:Construction Materials; D006801:Humans; D008956:Models, Chemical; D009518:New York; D053260:Soot / Q000032:analysis*; D014186:Transportation; D014919:Wind
chemical_list: D053260:Soot; D002244:Carbon
references.citation: Environ Health Perspect. 2010 Sep;118(9):1338-43
references.pmid: 20452882
references.citation: J Expo Anal Environ Epidemiol. 2003 Nov;13(6):443-53
references.pmid: 14603345
references.citation: Environ Sci Technol. 2009 Oct 15;43(20):7778-83
references.pmid: 19921893
references.citation: Atmos Environ (1994). 2011 Dec;45(39):7478-7486
references.pmid: 22125411
references.citation: Indoor Air. 2004 Aug;14(4):272-83
references.pmid: 15217480
references.citation: Environ Health Perspect. 2005 Dec;113(12):1741-6
references.pmid: 16330357
references.citation: J Expo Sci Environ Epidemiol. 2010 Jul;20(5):446-56
references.pmid: 19865073
references.citation: Atmos Environ (1994). 2009 Oct;43(32):4975-4981
references.pmid: 20161461
references.citation: Environ Health Perspect. 2011 Apr;119(4):559-65
references.pmid: 21216722
references.citation: Environ Health Perspect. 2002 Oct;110(10):1009-15
references.pmid: 12361926
references.citation: Environ Health Perspect. 2009 Nov;117(11):1767-72
references.pmid: 20049130