Composition, Sources, and Emissions PM2.5
Washington DC-MD-VA NAA
Sunil KumarTAC, COG
June 8, 2007
Washington DC-MD-VA PM2.5 NAA
PM2.5 Composition High Level DaysMcMillian (Washington, DC) - 2001-2003
Organics (k=2.4)50%
Geological2%
Soot4% Nitrate
19%
Sulfate13%
Ammonium10%
Trace Elements1%
Salt1%
Average 24-Hour PM2.5 Concentration = 38ug/m3Number of Days > 35ug/m3 = 4
Salt1%
Trace Elements1%
Ammonium12%
Sulfate20%
Nitrate20%
Soot4%
Geological2%
Organics (k=2.4)40%
Average 24-Hour PM2.5 Concentration = 39ug/m3Number of Days > 35ug/m3 = 1
Winter Spring
Salt0%
Trace Elements1%
Ammonium12%
Sulfate40%
Nitrate2%
Soot1%
Geological2%
Organics (k=2.4)42%
Average 24-Hour PM2.5 Concentration = 43ug/m3Number of Days > 35ug/m3 = 12
Organics (k=2.4)52%
Geological2% Soot
5%Nitrate
6%
Sulfate25%
Ammonium9%
Trace Elements1%
Salt0%
Average 24-Hour PM2.5 Concentration = 38ug/m3Number of Days > 35ug/m3 = 2
FallSummer
PM2.5 Composition STN DataMcMillian (Washington, DC) - 2004
Winter Summer
PM2.5 Composition STN DataMcMillian (Washington, DC) - 2004
Major species, McMilan Reservior, DC, in 2003
0
10
20
30
40
50
60
70
2003
0103
2003
0115
2003
0130
2003
0211
2003
0223
2003
0310
2003
0319
2003
0328
2003
0409
2003
0506
2003
0518
2003
0530
2003
0614
2003
0626
2003
0705
2003
0717
2003
0726
2003
0807
2003
0816
2003
0828
2003
0906
2003
0918
2003
0930
2003
1012
2003
1021
2003
1102
2003
1111
2003
1123
2003
1202
2003
1214
2003
1223
Con
cent
ratio
n (u
g/m
3)88101 (PM2.5STN)88301 (Ammonium)88302 (Sodium)88303 (Pottasium)88305 (Organic Carbon)OC.B88306 (Nitrate)88307 (Elemental Carbon)EC.B88403 (Sulfate)Reconstructed Mass (k=1.4)Reconstructed Mass (k=2.4)
PM2.5 - Source Contribution Kim & Hopke Source Apportionment of Fine Particles in Washington, DC, Utilizing
Temperature-Resolved Carbon Fractions (AWMA Journal, July 2004)
Study based on PM2.5 data (1988-97) for Washington, DC
Mostly OC
Total Sulfate = 60%
PM2.5 - Source Contribution
Battelle & Sonoma Tech EIGHT-SITE SOURCE APPORTIONMENT OF PM2.5 SPECIATION TRENDS DATA (September 2003)
PM2.5 - Source Contribution
DRI Report 2005 Source Apportionment Analysis of Air Quality Monitoring Data: Phase II (DRI Report, March 2005)
Seasonal Variation PM2.5 Components DRI Report 2005
Source Apportionment Analysis of Air Quality Monitoring Data: Phase II (DRI Report, March 2005)
Seasonal & Daily Variation PM2.5 Mass DRI Report 2005
Source Apportionment Analysis of Air Quality Monitoring Data: Phase II (DRI Report, March 2005)
Conclusion PM2.5 Composition Highest daily PM2.5 levels Summer & Winter
PM2.5 composition Component Summer Winter Annual (2004) Organics 42% 50% 28%(Organic & Elemental Carbon)
Sulfate 40% 13% 58% Ammonium 12% 10% Nitrate 2% 19% 7%
Organic & Elemental Carbon and Sulfate are the main constituents of PM2.5 in Washington, DC PM2.5 non-attainment area.
Conclusion Source Contribution
Source Contribution (Battelle Study) Coal combustion 46% Motor vehicles 28%
Gasoline vehicles Major source of organic carbon (OC = ~21% of total PM2.5 mass, Kim, Hopke)
Road construction 9% Ammonium Nitrate 7% Canadian fire 7% Vegetative burning 3%
Conclusion Source Contribution
Source Contribution (DRI Study)Source Summer Winter
Ammonium sulfate 52% 32% Vegetative burning 24% 21% Ammonium nitrate 5% 19% Motor vehicle 9% 15% Diesel vehicle 1% 2% Coal fired power plant 3% 6%
Comparison of Emissions (2002 vs. 2009)
BY 2002
4% 1%
32%
36%
27% PM25-PRI
NH3
NOX
SO2
VOC
Annual PM2.5 Inventories(Washington DC-MD-VA PM2.5 NAA)
0
50000
100000
150000
200000
250000
PM25-PRI NH3 NOX SO2 VOC
Pollutants
Emis
sion
s (t
on/y
r)
BY 2002
AY 2009AY 2009
8% 3%
31%
12%
46%
PM25-PRI
NH3
NOX
SO2
VOC
Comparison of Emissions (2002 vs. 2009)
Annual PM2.5 Point Source Inventory (2002 vs. 2009)(Washington DC-MD-VA PM2.5 NAA)
0
50000
100000
150000
200000
250000
PM25-PRI NH3 NOX SO2 VOC
Pollutants
Emis
sion
s (t
on/y
r)
BY 2002
AY 2009
Annual PM2.5 Area Source Inventory (2002 vs. 2009)(Washington DC-MD-VA PM2.5 NAA)
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
PM25-PRI NH3 NOX SO2 VOC
Pollutants
Emis
sion
s (t
on/y
r)
BY 2002
AY 2009
Annual PM2.5 Onroad Source Inventory (2002 vs. 2009)(Washington DC-MD-VA PM2.5 NAA)
01000020000300004000050000
60000700008000090000
100000
PM25-PRI NH3 NOX SO2 VOC
Pollutants
Emis
sion
s (to
n/yr
)
BY 2002
AY 2009
Annual PM2.5 Nonroad Source Inventory (2002 vs. 2009)(Washington DC-MD-VA PM2.5 NAA)
0
5000
10000
15000
20000
25000
30000
35000
PM25-PRI NH3 NOX SO2 VOC
Pollutants
Emis
sion
s (t
on/y
r)BY 2002
AY 2009
Area or Nonpoint Sources are the largest contributors of PM2.5-Pri emissions with road construction and residential wood burning emissions contributing the most.
ConclusionOrganic & Elemental Carbon and Sulfate are the main constituentsof PM2.5 in Washington, DC PM2.5 non-attainment area.
OC & EC are part of PM2.5-Pri emissions (emitted directly from sources). Sulfate forms due to oxidation of SO2 in the air and also due to reaction of SO2 with NH3 (Ammonium Sulfate).
Point sources are the largest contributors of PM2.5-Pri and SO2 emissions.
Area or Nonpoint Sources are the largest contributors of PM2.5-Pri emissions with road construction and residential wood burning emissions contributing the most.
NOx emissions from motor vehicles contribute significantly towards nitrate formation, an important constituent during winter.