title: Apportionment of urban aerosol sources in Cork (Ireland) by synergistic measurement techniques.
abstract: The sources of ambient fine particulate matter (PM2.5) during wintertime at a background urban location in Cork city (Ireland) have been determined. Aerosol chemical analyses were performed by multiple techniques including on-line high resolution aerosol time-of-flight mass spectrometry (Aerodyne HR-ToF-AMS), on-line single particle aerosol time-of-flight mass spectrometry (TSI ATOFMS), on-line elemental carbon-organic carbon analysis (Sunset_EC-OC), and off-line gas chromatography/mass spectrometry and ion chromatography analysis of filter samples collected at 6-h resolution. Positive matrix factorization (PMF) has been carried out to better elucidate aerosol sources not clearly identified when analyzing results from individual aerosol techniques on their own. Two datasets have been considered: on-line measurements averaged over 2-h periods, and both on-line and off-line measurements averaged over 6-h periods. Five aerosol sources were identified by PMF in both datasets, with excellent agreement between the two solutions: (1) regional domestic solid fuel burning--"DSF_Regional," 24-27%; (2) local urban domestic solid fuel burning--"DSF_Urban," 22-23%; (3) road vehicle emissions--"Traffic," 15-20%; (4) secondary aerosols from regional anthropogenic sources--"SA_Regional" 9-13%; and (5) secondary aged/processed aerosols related to urban anthropogenic sources--"SA_Urban," 21-26%. The results indicate that, despite regulations for restricting the use of smoky fuels, solid fuel burning is the major source (46-50%) of PM2.5 in wintertime in Cork, and also likely other areas of Ireland. Whilst wood combustion is strongly associated with OC and EC, it was found that peat and coal combustion is linked mainly with OC and the aerosol from these latter sources appears to be more volatile than that produced by wood combustion. Ship emissions from the nearby port were found to be mixed with the SA_Regional factor. The PMF analysis allowed us to link the AMS cooking organic aerosol factor (AMS_PMF_COA) to oxidized organic aerosol, chloride and locally produced nitrate, indicating that AMS_PMF_COA cannot be attributed to primary cooking emissions only. Overall, there are clear benefits from factor analysis applied to results obtained from multiple techniques, which allows better association of aerosols with sources and atmospheric processes.
authors.affiliation: School of Physics and Centre for Climate and Air Pollution Studies, Ryan Institute, National University of Ireland Galway, Galway, Ireland; Institut de Ciències del Mar, CSIC, Pg Marítim de la Barceloneta 37-49 Barcelona, Spain. Electronic address: manuel.dallosto@gmail.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Dall'Osto
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland; Laboratoire Chimie Environment, Aix Marseille Université, Marseille 13 331, France.
authors.forename: Stig
authors.initials: S
authors.lastname: Hellebust
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland; Southern Ontario Centre for Atmospheric Aerosol Research, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Healy
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland.
authors.forename: Ian P
authors.initials: IP
authors.lastname: O'Connor
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland; Department of Chemistry, University of Cambridge, Cambridge, UK.
authors.forename: Ivan
authors.initials: I
authors.lastname: Kourtchev
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland.
authors.forename: John R
authors.initials: JR
authors.lastname: Sodeau
authors.affiliation: School of Physics and Centre for Climate and Air Pollution Studies, Ryan Institute, National University of Ireland Galway, Galway, Ireland.
authors.forename: Jurgita
authors.initials: J
authors.lastname: Ovadnevaite
authors.affiliation: School of Physics and Centre for Climate and Air Pollution Studies, Ryan Institute, National University of Ireland Galway, Galway, Ireland.
authors.forename: Darius
authors.initials: D
authors.lastname: Ceburnis
authors.affiliation: School of Physics and Centre for Climate and Air Pollution Studies, Ryan Institute, National University of Ireland Galway, Galway, Ireland.
authors.forename: Colin D
authors.initials: CD
authors.lastname: O'Dowd
authors.affiliation: Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland.
authors.forename: John C
authors.initials: JC
authors.lastname: Wenger
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods*; D007494:Ireland; D052638:Particulate Matter / Q000032:analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: AMS; ATOFMS; Cooking aerosol; PMF; Source apportionment; Urban aerosol