Presentation given by Prof John Wenger at the 2015 Clean Air Conference, 28/09/15, Dublin

1. Urban and Rural Sources of
Particulate Matter
John Wenger
Centre for Research into Atmospheric Chemistry
Environmental Research Institute
University College Cork
Ireland
Email: j.wenger@ucc.ie web: http://www.ucc.ie/en/crac/

2. Outline
• Properties of Particulate Matter (PM)
• Linking chemical composition and sources of PM
• Case Studies
- Cork City
- Killarney
• Summary and Perspectives

3. Particulate Matter
PM10 - Particulate Matter with diameter less than 10 microns
PM2.5 - Particulate Matter with diameter less than 2.5 microns

4. All Shapes and Sizes
• Large number of particles < 0.1 microns
• Majority of mass in range 0.1-10 microns

5. Natural Anthropogenic
Primary Sources

6. • Formation and growth of particles in the atmosphere
• Ammonium, sulfate, nitrate, secondary organic aerosol
Gas +
scavenging
Particle Particle
Particle Particle+
coagulation
Particle
Gas Gas+
nucleation
Particle
Gas
condensation
Particle
Secondary Sources

7. Fine fraction (PM2.5) Coarse fraction (PM2.5-PM10)
• Approximate composition of PM in Ireland determined
by off-line analysis of filter samples
Chemical Composition
Elemental and
Organic Carbon
Sulphate
Nitrate
Ammonium
Chloride
Insoluble minerals
Na, K, Mg, Ca

8. Chemical species Sources
Elemental/Black Carbon
(EC or BC)
Fuel combustion (automobiles,
industry, coal/wood burning)
Organic Carbon Fuel combustion, secondary organic
aerosols from VOC oxidation processes
Nitrate / Sulfate Gas-particle conversion of NO2 / SO2
produced from combustion processes
Ammonium Gas-particle conversion of NH3
produced from agriculture
Chloride Sea spray
Minerals (Oxides of Ca, Mg,
Si, Al, Fe)
Resuspension of dust/soil
Metals (K, V and Ni, Pb, Zn,
Cd, Hg etc.)
Industry, combustion, often specific
sources
Linking Composition and Sources of PM

9. Reducing PM levels
We need to know AND quantify the sources
• How much PM is from traffic?
• How much PM is from solid fuel burning?
• How much PM is from other sources?
• How do the emissions from these sources vary
during the day and by season?
Detailed measurements of the PM are required
• Size, concentration and chemical composition at a
HIGH-TIME resolution
• Source Apportionment Modelling

10. Case Study: Cork Harbour
• Long-term (1 year)
monitoring campaigns
• Intensive (1 month)
measurement campaigns

11. X
B
B
B
Tivoli Docks August 2008 and February 2009
Intensive Measurement Campaign
Healy et al., Atmospheric Chemistry and Physics 2010

12. Tivoli Docks August 2008 and February 2009
Intensive Measurement Campaign
A range of state-of-the-art instruments deployed
for On-line monitoring of particle mass, size,
number and chemical composition in real-time

13. Aerosol Time-of-Flight Mass Spectrometer
• Detects elemental
carbon, organic carbon,
metals, inorganic ions
in single particles
• Provides size-resolved
chemical composition
(0.1-3.0 micron)
• Operates in real-time
→ big advantage over
filter collection and off-
line analysis approach

14. Sea-Salt Particle Mass
Spectrum (Na and Cl are
markers of interest)
Biomass Burning Particle
Mass Spectrum (K is major
marker for biomass)
Single Particle Mass Spectra

15. Sources in Cork Harbour: 3 Vehicular Traffic
0
500
1000
1500
2000
2500
ATOFMScounts(h-1)
Time
Ca-traffic EC-traffic EC-phos
Sources in Cork Harbour: Vehicular Traffic
Healy et al., Atmospheric Chemistry and Physics 2010

16. 0
50
100
150
200
250
0
100
200
300
400
500
600
700
800
ATOFMScounts(h-1)
ATOFMScounts(h-1)
Time
coal peat wood
Sources in Cork Harbour: Solid Fuel Combustion
Healy et al., Atmospheric Chemistry and Physics 2010

17. • State-of-the-art analytical techniques used to apportion PM mass
Source Apportionment of PM
Healy et al., Atmospheric Chemistry and Physics, 2010
PM2.5
average
(µg/m3)
Solid Fuel
Burning
%
Traffic
%
Other
Local
Sources
%
Regional
Sources
%
August
2008
9.7 5 23 24 26
February
2009
16.2 50 19 21 10
Kourtchev et al., Science of the Total Environment, 2011
Dall’Osto et al., Atmospheric Chemistry and Physics, 2013

18. Extent of Bituminous Coal Ban 2015

19. • What is the contribution of residential solid fuel burning
to PM levels in towns where the Ban on Bituminous Coal
is not in place?
The Burning Question

20. What is the contribution of each fuel type?
Sod Peat (Turf)
“Smokeless” Coal
Wood
Bituminous (Smoky) Coal
Peat Briquettes

21. Source Apportionment of Particulate Matter in
Urban and Rural Residential Areas of Ireland
(SAPPHIRE)
1 April 2014 – 31 March 2016
http://www.ucc.ie/en/crac/research/sapphire/

22. • Outside the Smoky Coal
Ban Area (pop. < 15,000)
• No natural gas supply
• High usage of solid fuels
(coal, peat/turf & wood)
Monitoring Locations
• Killarney, Co. Kerry (Nov & Dec 2014)
• Enniscorthy, Co. Wexford (Jan & Feb 2015)
K
E

23. • Site is located on the western side of the town, in the
grounds of the Community Hospital in a residential area
Monitoring Location: Killarney

24. • Site is located on the western side of the town, in the
grounds of the Community Hospital in a residential area
Monitoring Location: Killarney

25. TEOM
PM2.5 mass concentration
• PM2.5 up to 10 times higher during evening hours

26. PM2.5 mass concentration
• Strong diurnal pattern

27. Aerosol Time-of-Flight Mass Spectrometer
• Detects elemental
carbon, organic carbon,
metals, inorganic ions
in single particles
• Provides size-resolved
chemical composition
(0.1-3.0 micron)
• Operates in real-time
→ big advantage over
filter collection and off-
line analysis approach

28. PEAT
PEAT
WOOD
COAL
COAL
EC
Sulfate
Potassium
Assigned on the basis of combustion
experiments
COAL → EC & some potassium, sulfate
dominates negative spectra
PEAT → EC & OC fragments, some
potassium
WOOD → Potassium dominates
positive spectra
EC
OC
WOOD
Mass Spectra: Solid Fuel Combustion

29. SEA SALT
TRAFFIC
AMINE/
AMMONIUM
Na
Cl
NaCl2
Na2Cl3 Sea salt characteristics:
→ sodium & chloride peaks, no EC
Traffic characteristics:
→ calcium & phosphate (lubricating
oil), some EC
Phosphate
Calcium
Ammonium/amine characteristics:
→ ammonium, trimethylamine, OC,
large sulfate peak in negative spectra
Ammonium
Mass Spectra: Other Particle Types

30. Transported
sea salt
ATOFMS Particle Number
• Low wind speed – local emissions dominate
• High wind speed – regional sources dominate

31. Particles from solid fuel burning
80% of PM2.5
Particle Numbers
Particles from solid fuel burning
77% of PM2.5
Particle Mass
ATOFMS: Source Contribution to PM2.5
Mass
Scaling

32. • Local sources account for 70-90% of PM2.5 in Cork City.
Traffic accounts for ~20%; solid fuel burning 50% in winter.
• Residential solid fuel burning contributes 70-80% of PM2.5
in Killarney in winter
• Similar results for Enniscorthy: also likely replicated in tens
of small towns across Ireland.
• Peat, coal and wood all contribute: Extending the smoky
coal ban may not be enough to deliver improvements in
air quality
• No source apportionment study yet performed in Dublin!
Summary and Perspectives

33. Acknowledgements
John Sodeau
Ian O’Connor Eoin McGillicuddy Jovanna Arndt
Paul BuckleyStig Hellebust

34. Extra Slides

35. • Missing mass due to regional sources – organic aerosol,
ammonium sulfate?
ATOFMS Particle Mass vs TEOM

36. Particles directly emitted from solid fuel combustion
= 66% of measured PM2.5
Source contributions (% of TEOM PM2.5)

37. Killarney: ATOFMS Mass: Diurnal
• Particle numbers for entire
sampling period averaged to 1
day → clear evening peak shows
influence of solid fuel burning on
total particle numbers.
• Clear evening peak in averaged
mass concentration:
‒ peat (16 μg/m3)
‒ wood (12 μg/m3)
‒ coal (10 μg/m3)
(combined 38 μg/m3 average per
night)
29/09/15
SAPPHIRE Meeting: ATOFMS (Jovanna
Arndt)
37

38. Unidentified
30%
Marine
and Aged
6%
Local Aged
4%Traffic
3%Amines
5%
Burning
52%
Preliminary Source Apportionment
• 5 factors identified
• Primary emissions from
solid fuel burning
= 52% of PM2.5 …….but
no separation by fuel
type
• PMF ME-2 using ATOFMS particle classes, EC-OC,
SMPS, OPS, NOx, Aethalometer

39. Instrument Parameter(s) measured Temporal
resolution
Aerosol time-of-flight mass
spectrometer (TSI model 3800)
Single particle chemical
composition (100-3000 nm)
1 min
Scanning mobility particle sizer
(TSI model 3081)
Particle number concentration
(10-800 nm)
3 min
Optical Particle Sizer (TSI model
3330)
Particle number concentration
(300-10000 nm)
3 min
TEOM (Thermo Electron model RP
1400a)
PM2.5 mass concentration 30 min
Thermal-optical carbon analyser
(Sunset Inc. model 3rd generation)
Elemental and organic carbon
mass concentrations
2 hr
7-Wavelength Aethalometer
(Model AE33, Magee Scientific)
Black Carbon concentration 1 min
High volume sampler (Digitel
model DHA 80)
Collection of particulate
matter (PM2.5)
6 hr
Key Instrumentation

40. TEOM
Sunset
ECOC
Elemental and Organic Carbon (EC/OC)
• Majority of PM2.5 during night-time pollution events is
carbonaceous aerosol

41. Low winds – Local sources High winds – Regional sources
Influence of Meteorology
• Low wind speed – local emissions dominate
• High wind speed – regional sources dominate

42. Enniscorthy: ATOFMS Mass: Diurnal
• Averaged ATOFMS mass
concentration per day
maximum = ~ 60 μg/m3
• Peak averaged daily mass
concentrations:
− peat (16 μg/m3)
− wood (14 μg/m3)
− coal (12 μg/m3)
− PAH-containing (9 μg/m3)
29/09/15
SAPPHIRE Meeting: ATOFMS (Jovanna
Arndt)
42

43. Enniscorthy: ATOFMS Mass Breakdown
29/09/15
SAPPHIRE Meeting: ATOFMS (Jovanna
Arndt)
43
Solid fuel combustion particles = 89% of
ATOFMS PM2.5 mass
(no comparison with TEOM yet so this % will
probably decrease a bit)
PAH-containing particles associated with all
three fuel types.