title: Real-world emission factors for antimony and other brake wear related trace elements: size-segregated values for light and heavy duty vehicles.
abstract: Hourly trace element measurements were performed in an urban street canyon and next to an interurban freeway in Switzerland during more than one month each, deploying a rotating drum impactor (RDI) and subsequent sample analysis by synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). Antimony and other brake wear associated elements were detected in three particle size ranges (2.5-10, 1-2.5, and 0.1-1 microm). The hourly measurements revealed that the effect of resuspended road dust has to be taken into account for the calculation of vehicle emission factors. Individual values for light and heavy duty vehicles were obtained for stop-and-go traffic in the urban street canyon. Mass based brake wear emissions were predominantly found in the coarse particle fraction. For antimony, determined emission factors were 11 +/- 7 and 86 +/- 42 microg km(-1) vehicle(-1) for light and heavy duty vehicles, respectively. Antimony emissions along the interurban freeway with free-flowing traffic were significantly lower. Relative patterns for brake wear related elements were very similar for both considered locations. Beside vehicle type specific brake wear emissions, road dust resuspension was found to be a dominant contributor of antimony in the street canyon.
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Testing and Research, CH-8600 Duebendorf, Switzerland. nicolas.bukowiecki@empa.ch
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bukowiecki
authors.forename: Peter
authors.initials: P
authors.lastname: Lienemann
authors.forename: Matthias
authors.initials: M
authors.lastname: Hill
authors.forename: Renato
authors.initials: R
authors.lastname: Figi
authors.forename: Agnes
authors.initials: A
authors.lastname: Richard
authors.forename: Markus
authors.initials: M
authors.lastname: Furger
authors.forename: Karen
authors.initials: K
authors.lastname: Rickers
authors.forename: Gerald
authors.initials: G
authors.lastname: Falkenberg
authors.forename: Yongjing
authors.initials: Y
authors.lastname: Zhao
authors.forename: Steven S
authors.initials: SS
authors.lastname: Cliff
authors.forename: Andre S H
authors.initials: AS
authors.lastname: Prevot
authors.forename: Urs
authors.initials: U
authors.lastname: Baltensperger
authors.forename: Brigitte
authors.initials: B
authors.lastname: Buchmann
authors.forename: Robert
authors.initials: R
authors.lastname: Gehrig
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D000965:Antimony / Q000032:analysis*; D018986:Motor Vehicles; D010316:Particle Size; D012621:Seasons; D013557:Switzerland; D013997:Time Factors; D014131:Trace Elements / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D014131:Trace Elements; D001335:Vehicle Emissions; D000965:Antimony