Ultrafine particles in four European urban environments: Results from a new continuous long-term monitoring network
journal contributionposted on 09.01.2017, 16:47 by J. Hofman, J. Staelens, R. Cordell, C. Stroobants, N. Zikova, S. M. L. Hama, K. P. Wyche, G. P. A. Kos, S. Van der Zee, K. L. Smallbone, E. P. Weijers, P. S. Monks, E. Roekens
o gain a better understanding on the spatiotemporal variation of ultrafine particles (UFPs) in urban environments, this study reports on the first results of a long-term UFP monitoring network, set up in Amsterdam (NL), Antwerp (BE), Leicester (UK) and London (UK). Total number concentrations and size distributions were assessed during 1–2 years at four fixed urban background sites, supplemented with mobile trailer measurements for co-location monitoring and additional short-term monitoring sites. Intra- and interurban spatiotemporal UFP variation, associations with commonly-monitored pollutants (PM, NOx and BC) and impacts of wind fields were evaluated. Although comparable size distributions were observed between the four cities, source-related differences were demonstrated within specific particle size classes. Total and size-resolved particle number concentrations showed clear traffic-related temporal variation, confirming road traffic as the major UFP contributor in urban environments. New particle formation events were observed in all cities. Correlations with typical traffic-related pollutants (BC and NOx) were obtained for all monitoring stations, except for Amsterdam, which might be attributable to UFP emissions from Schiphol airport. The temporal variation in particle number concentration correlated fairly weakly between the four cities (rs = 0.28−0.50, COD = 0.28−0.37), yet improved significantly inside individual cities (rs = 0.59−0.77). Nevertheless, considerable differences were still obtained in terms of particle numbers (20–38% for total particle numbers and up to 49% for size-resolved particle numbers), confirming the importance of local source contributions and the need for careful consideration when allocating UFP monitoring stations in heterogeneous urban environments.
This research was carried out in the framework of the Joint Air Quality Initiative (Joaquin) project, supported by the EU INTERREG IVB NWE Programme. The corresponding author acknowledges the Research Foundation Flanders (FWO) for his postdoctoral fellowship.
CitationAtmospheric Environment, 2016, 136, pp. 68-81 (14)
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING
VersionAM (Accepted Manuscript)
Published inAtmospheric Environment
NotesSupplementary data related to this article can be found at http://dx.doi.org/10.1016/j.atmosenv.2016.04.010.
Science & TechnologyLife Sciences & BiomedicinePhysical SciencesEnvironmental SciencesMeteorology & Atmospheric SciencesEnvironmental Sciences & EcologyUFPUrban particle size distributionAmsterdamAntwerpLeicesterLondonNUMBER SIZE DISTRIBUTIONSINTERNATIONAL-AIRPORTBLACK CARBONAIR-QUALITYPARTICULATE MATTERCITIESEMISSIONSVARIABILITYEXPOSUREANGELES