1. The study used single particle mass spectrometry to identify sources of PM2.5 in Cork Harbour, Ireland. Major sources identified were traffic, sea spray, and local combustion including domestic solid fuel burning.
2. While shipping traffic contributed little to PM2.5 mass, it accounted for almost half of total particle number concentration, similar to traffic emissions.
3. Unique mass spectral fingerprints from the single particle technique provided a useful alternative to offline chemical analysis for source apportionment of PM2.5.
1. IAC Helsinki 30/08/2010
Source Apportionment of PM2.5 in Cork Harbour,
Ireland using single particle mass spectrometry
R. M. Healy1, S. Hellebust1, I. Kourtchev1, A. Allanic1, I. O’Connnor1, J. Bell1,
M. Dall’Osto2, D. Ceburnis2, J. Ovadnevaite2, H. Berresheim2, C. O’Dowd2,
J. Sodeau1, J. Wenger1
1Department of Chemistry and Environmental Research Institute, University College Cork, Ireland
2School of Physics and Centre for Climate and Pollution Studies, Environmental Change Institute,
National University of Ireland Galway, Ireland
2. Aims
IAC Helsinki 30/08/2010
1: To measure the size-resolved chemical composition of single particles in
Cork Harbour using Aerosol Time-of-Flight Mass Spectrometry (ATOFMS)
2: To use this information to identify sources of PM2.5 with an emphasis on
local shipping emissions
3: To combine ATOFMS data with other semi-continuous measurements in
order to estimate the contribution of each source to ambient PM2.5 mass
concentration and particle number concentration
3. Sampling Site
IAC Helsinki 30/08/2010
X
B
B
B
0.05 0.1 0.15 0.2
0
45
90
135
180
225
270
315
0 - 2
2 - 4
4 - 6
6 - 8
8+
(m s
-1
)
Sampling carried out at Tivoli Docks, Cork
Harbour for three weeks (7-28/08/2008)
R. M. Healy et al., Atmos. Chem. Phys. Discuss. 10, 1035-1082, 2010
4. Instrumentation
IAC Helsinki 30/08/2010
Instrument Measurement
ATOFMS (TSI, 3800) Size-resolved single particle chemical
composition
SMPS (TSI, 3081) Particle number (20-700 nm)
TEOM (Thermo, 1400a) PM2.5
Thermal-optical carbon analyser
(Sunset, 3rd gen. field model)
ECOC
Sulfate analyser (Thermo, 5020 SPA) Particulate SO4
2-
5. IAC Helsinki 30/08/2010
Data Analysis
1: Over 500,000 particle mass spectra were collected, imported into
ENCHILADA1 and clustered using the K-means algorithm (K=50)
2: 50 clusters reduced to 14 ATOFMS classes; Peat, Coal, Wood, Sea salt,
Shipping, Ca-traffic, EC-traffic, EC-phos, EC-MSA, EC-domestic, EC-background,
EC-oil, ECOC, and Oligomer
3: ATOFMS counts for each class were sorted into hourly bins and used along
with hourly averages of EC/OC, SO4
2- and hourly integrated SMPS particle
counts for positive matrix factorisation (PMF) in order to reconstruct PM2.5
mass concentrations
1D. Gross et al., Environmental Modelling & Software 25, 760-769, 2010
15. IAC Helsinki 30/08/2010
Conclusions
1: Unique mass spectral fingerprints and high time resolution of ATOFMS are
suited to source identification and apportionment, representing a useful
alternative to off-line chemical analysis of PM2.5
2: The major sources of PM2.5 in Cork Harbour during the summer are traffic
and sea spray, followed by local combustion processes including a contribution
from domestic solid fuel burning
3: Although shipping traffic contributes very little to PM2.5 mass
concentrations, the contribution to particle number concentration is almost
half that of traffic
16. IAC Helsinki 30/08/2010
Acknowledgements
Port of Cork for providing a suitable sampling site
Higher Education Authority, Environmental Protection Agency
and Science Foundation Ireland for providing funding for this
research
Thank you for your attention!
23. IAC Helsinki 30/08/2010
Fig. 15: 5 day back-trajectories for air masses arriving at Cork Harbour on at 00:00 h
on 10 (left), 14 (middle) and 26 August 2008 (right).