Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 15, 2367-2386, 2015
https://doi.org/10.5194/acp-15-2367-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
04 Mar 2015
Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012
S. Visser1, J. G. Slowik1, M. Furger1, P. Zotter1,*, N. Bukowiecki1, R. Dressler2, U. Flechsig3, K. Appel4,**, D. C. Green5, A. H. Tremper5, D. E. Young6,***, P. I. Williams7,6, J. D. Allan7,6, S. C. Herndon8, L. R. Williams8, C. Mohr9,****, L. Xu10, N. L. Ng11,10, A. Detournay12, J. F. Barlow13, C. H. Halios13, Z. L. Fleming14,7, U. Baltensperger1, and A. S. H. Prévôt1 1Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Switzerland
2Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, Villigen, Switzerland
3Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland
4HASYLAB, DESY Photon Science, Hamburg, Germany
5School of Biomedical Sciences, King's College London, London, UK
6School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, UK
7National Centre for Atmospheric Science, University of Manchester, Manchester, UK
8Aerodyne Research, Inc., Billerica, MA, USA
9Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
10School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
11School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
12Centre for Ecology and Hydrology, Penicuik, Midlothian, UK
13Department of Meteorology, University of Reading, Reading, UK
14Department of Chemistry, University of Leicester, Leicester, UK
*now at: Lucerne School of Engineering and Architecture, Bioenergy Research, Lucerne University of Applied Sciences and Arts, Horw, Switzerland
**now at: European XFEL, Hamburg, Germany
***now at: Department of Environmental Toxicology, University of California, Davis, CA, USA
****now at: Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
Abstract. Ambient concentrations of trace elements with 2 h time resolution were measured in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3–6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6–3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10–2.5 mass fraction, roughly twice that of the PM1.0–0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4–5.4 for SW, 1.7–2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10–2.5 sea salt (factor of up to 2), which may be influenced by traffic-induced resuspension of sea and/or road salt. Heavy-duty vehicles appeared to have a larger effect than passenger vehicles on the concentrations of all elements influenced by resuspension (including sea salt) and wearing processes. Trace element concentrations in London were influenced by both local and regional sources, with coarse and intermediate fractions dominated by traffic-induced resuspension and wearing processes and fine particles influenced by regional transport.

Citation: Visser, S., Slowik, J. G., Furger, M., Zotter, P., Bukowiecki, N., Dressler, R., Flechsig, U., Appel, K., Green, D. C., Tremper, A. H., Young, D. E., Williams, P. I., Allan, J. D., Herndon, S. C., Williams, L. R., Mohr, C., Xu, L., Ng, N. L., Detournay, A., Barlow, J. F., Halios, C. H., Fleming, Z. L., Baltensperger, U., and Prévôt, A. S. H.: Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012, Atmos. Chem. Phys., 15, 2367-2386, https://doi.org/10.5194/acp-15-2367-2015, 2015.
Publications Copernicus
Download
Short summary
Ambient concentrations of trace elements with 2h time resolution were measured in three size ranges (PM10–2.5, PM2.5–1.0, PM1.0–0.3) at kerbside, urban background and rural sites in London during the ClearfLo (Clean Air for London) field campaign. Quantification of kerb and urban increments, and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure.
Ambient concentrations of trace elements with 2h time resolution were measured in three size...
Share