title: Hotspots of black carbon and PM2.5in an urban area and relationships to traffic characteristics.
abstract: Three instrumented bicycles were used to measure black carbon (BC) and PM2.5concentrations in a midsized city in southern Brazil. The objective of this study was to map the spatial distribution of BC and PM2.5, to identify air pollution hotspots and to assess factors that may affect the concentrations of these pollutants, e.g. traffic volume, number of heavy-duty diesel vehicles (HDDV), position of traffic signals and street incline. The cyclists collected data in the city centre along streets of different traffic density during nine sampling sessions in the weekday morning and afternoon rush hours, between March 13 and April 28, 2015. The sampling by bicycle covered an area of 2.70 km2, over variable elevation, and travelled a total distance of 215 km. BC and PM2.5exhibited a large spatial variability on a scale of tens of metres and the concentrations were positively correlated with traffic counts, but exhibited a stronger relationship with the number of HDDV. These results imply that older buses and diesel-powered trucks may be the main driver behind the high pollution levels in the city's inner core. We observed a strong relationship between BC concentrations at junctions managed by traffic signals and the quantity of HDDV. The mean BC concentration was found to be 8.10 μg m-3near traffic signals located on an inclined street (HDDV > 100 vehicles h-1) compared to traffic signals on flat terrain (6.00 μg m-3), which can be attributed to the higher acceleration required at the start of motion. This pattern was less evident for PM2.5concentrations.
authors.affiliation: Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil. Electronic address: admirtargino@utfpr.edu.br.
authors.forename: Admir Créso
authors.initials: AC
authors.lastname: Targino
authors.affiliation: Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia, B3H 4R2, Canada.
authors.forename: Mark David
authors.initials: MD
authors.lastname: Gibson
authors.affiliation: Graduate Program in Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Krecl
authors.affiliation: Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
authors.forename: Marcos Vinicius Costa
authors.initials: MVC
authors.lastname: Rodrigues
authors.affiliation: Department of Environmental Engineering, Federal University of Technology, Av. Pioneiros 3131, 86036-370, Londrina, PR, Brazil.
authors.forename: Maurício Moreira
authors.initials: MM
authors.lastname: Dos Santos
authors.affiliation: Natural Resources Department, Federal University of Itajubá, Av. BPS 1303, 37500-903, Itajubá, MG, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Paula Corrêa
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis; D001938:Brazil; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D018986:Motor Vehicles; D052638:Particulate Matter / Q000032:analysis*; D053260:Soot / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions
keywords: Mobile sampling; Particulate matter; Short-lived climate pollutants; Urban air pollution