Size and time-resolved roadside enrichment of atmospheric particulate pollutants 1Institute of Environmental Assessment and Water Research, Spanish Research Council (IDǼA-CSIC), C/Jordi Girona 18-26, 08034 Barcelona, Spain
29 Mar 2011
2Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
3National Institute of Nuclear Physics (INFN) and Department of Physics and Astronomy, University of Florence, via Sansone 1, 50019 SestoFiorentino, Italy
Received: 02 Nov 2010 – Published in Atmos. Chem. Phys. Discuss.: 07 Jan 2011 Abstract. Size and time-resolved roadside enrichments of atmospheric particulate
pollutants in PM10 were detected and quantified in a Mediterranean
urban environment (Barcelona, Spain). Simultaneous data from one urban
background (UB), one traffic (T) and one heavy traffic (HT) location were
analysed, and roadside PM10 enrichments (RE) in a number of elements
arising from vehicular emissions were calculated. Tracers of primary traffic
emissions (EC, Fe, Ba, Cu, Sb, Cr, Sn) showed the largest REs (>70%).
Other traffic tracers (Zr, Cd) showed lower but still consistent REs
(25–40%), similar to those obtained for mineral matter resulting from
road dust resuspension (Ca, La, Ce, Ti, Ga, Sr, 30–40%). The sum of
primary and secondary organic carbon showed a RE of 41%, with
contributions of secondary OC (SOC) to total OC ranging from 46% at the
HT site, 63% at the T site, and 78% in the UB. Finally, other trace
elements (As, Co, Bi) showed unexpected but consistent roadside enrichments
(23% up to 69%), suggesting a link to traffic emissions even though
the emission process is unclear.
Revised: 16 Mar 2011 – Accepted: 22 Mar 2011 – Published: 29 Mar 2011
Hourly-resolved PM speciation data proved to be a highly resourceful tool to
determine the source origin of atmospheric pollutants in urban environments.
At the HT site, up to 62% of fine Mn was attributable to industrial
plumes, whereas coarse Mn levels were mainly attributed to traffic.
Similarly, even though Zn showed on average no roadside enrichment and thus
was classified as industrial, the hourly-resolved data proved that at least
15% of coarse Zn may be attributed to road traffic emissions. In
addition, our results indicate that secondary nitrate formation occurs
within the city-scale, even in the absence of long atmospheric residence
times or long-range atmospheric transport processes. Characteristic tracer
ratios of road traffic emissions were identified: Cu/Sb = 6.8–8.0,
Cu/Sn = 4.7–5.4 and Sn/Sb = 1.5.
Citation: Amato, F., Viana, M., Richard, A., Furger, M., Prévôt, A. S. H., Nava, S., Lucarelli, F., Bukowiecki, N., Alastuey, A., Reche, C., Moreno, T., Pandolfi, M., Pey, J., and Querol, X.: Size and time-resolved roadside enrichment of atmospheric particulate pollutants, Atmos. Chem. Phys., 11, 2917-2931, doi:10.5194/acp-11-2917-2011, 2011.