Source Apportionment of Fine Particulate Matter
in the U.S. and Associations with Lung
Inflammatory Markers IL-8, COX-2, and HO-1
R.M. Duvall1, G.A. Norris1, J.M. Burke1,
J.K. McGee2, M.I. Gilmour2, and R.B. Devlin2
1 National Exposure Research Laboratory, U.S. Environmental Protection
Agency, Research Triangle Park, NC, 27711
2 National Health and Environmental Effects Laboratory, U.S.
Environmental Protection Agency, Research Triangle Park, NC 27711
INTRODUCTION AND BACKGROUND
SOURCE APPORTIONMENT
Associations are well established between particulate matter (PM) mass
concentrations and increased human mortality and morbidity. Fine particulate
matter (particle diameter < 2.5 mm) is most strongly linked to adverse health
impacts. The toxicity of PM may depend on the PM source (e.g. vehicle
exhaust, coal combustion, etc.) and composition of PM which will vary by
location. While a number of epidemiological studies have shown that certain
PM sources are associated with specific health outcomes, the mechanisms
are still unclear.
In this study, the association between fine PM sources and three lung
inflammatory markers (interleukin-8, cyclooxygenase-2, and heme
oxygenase-1) was evaluated in multiple cities with contrasting PM sources as
part of the Multiple Pollutant Study (MAPS).
The EPA Chemical Mass Balance Model (EPA CMB8.2) was used to
quantify the sources impacting each site.
Operational scheme of the CMB Model:
Speciated data from
each sampling site
Source Profiles
Estimated source
contributions to each site
SAMPLING AND ANALYSIS
Fine particles were collected in six sites in the U.S. from December 2003 to
May 2004 [See map below]. One-week samples (24-hrs a day) were
collected at each site over a 4-week period using a ChemVol high-volume
cascade impactor operating at a flowrate of 800 L/min. Samples were
analyzed for the following:
Chemical Speciation
¦ Trace metals [Inductively Coupled Plasma - Optical Emission
Spectroscopy]
¦ Ions [Ion Chromatography]
¦ Elemental Carbon [Thermal Evolution and Combustion]
Lung Inflammatory Markers
¦ Interleukin (IL) - 8 [Enzyme - Linked Immunosorbent Assay]
¦ Heme oxygenase (HO)-1 and cyclooxygenase (COX)-2 [Reverse
Transcriptase - Polymerase Chain Reaction]
A linear regression was used to determine the
relationship between PM sources and health effects
Conclusions
Different source contributions across the sampling sites allowed
for evaluation of the relationship between sources contributions
and the inflammatory markers. Each inflammatory marker showed
varying relationships with the sources. IL-8 and HO-1 were both
correlated with secondary sulfate from coal combustion, although
at differing levels. Weak associations were observed with COX-2
to wood combustion, residual oil combustion, and soil.
Combustion and industrial sources appear to elicit an
inflammatory response which is consistent with previous health
studies.
Disclaimer: Although this work was reviewed by EPA and
approved for publication, it may not necessarily reflect official
Agency policy.
L_
Source Contributions to MAPS Sampling sites
I Mobile Sources
D Residual Oil Combustion
I Wood Combustion
I Soil Dust
3 Secondary Sulfate
I Secondary Nitrate
~OoUUb
: ' : ¦ ¦ ' ¦
Results
Sources Compared to IL - 8
• +
X 0
y= 2.11x+6.02 A
R2=0.01
0.00 0.10 0.20 0.30
Residual Oil Combustion (pfl/m3)
Legend:
¦ Salt Lake City
~ Seattle
x Phoenix
o Sterling Forest
~ South Bronx
+ Hunter College
0.00 1.00 2.00 3.00 4.00
Wood Combustion f^g/m3)
(Sterling Forest data
10.00 ny=2.77x+0.35
R2= 0.79
5.00 -
0.00 1.00 2.00 3.00 4.00
Secondary Sulfate (fxg/m3)
10-00 -I y= 2.82x+ 1.03
R2= 0.63
0.00 0.50 1.00 1.50 2.00 2.50
Secondary Nitrate (jj.g/m3)
Sources Compared to COX-2
10 00
{ 5 00
0 00
y = 0.74x + 7.05
R2 = 0.22
10.00
t 5.00
0.00
1. 4
•
y =5.02x +7.13
R2 = 0.38
10.00
: 5.00
0.00
Legend:
¦ Salt Lake City
~ Seattle
x Phoenix
o Sterling Forest
~ South Bronx
+ Hunter College
y = 051x + 673
R = 0 33
0 00 050 1 00 1 50
Mobile Sources (^g/m3)
0 00 0 10 0 20 0 30
Residual Oil Combustion (p.g/m3)
0 00 1 00 2 00 3 00
Wood Combustion (}ig/m3)
A
w.
y = 3.43x + 7.28
R2 = 0.48
1000
5.00
S tcrhng Fores: data rt
y = 0.14x + 7.58
R2 = 0.01
0.10 0.20
Soil (jig/m3)
0.00 1.00 2.00 3.00
Secondary Sulfate (jig/m3)
1000
5.00
0.00
y =-0.55x + 8.71
R2 = 0.12
0.00 1.00 2.00
Secondary Nitrate (jig/m3)
30 00
t- 20 00
o
= 10.00
0 00
y= 1.53X+ 17.12
R2= 0.02
Sources Compared to HO - 1
30 00
20 00
10.00
0 00
0
• +
X
y=2.72x+18.15
R =000
30 00
20 00
10 00 - y = -6.26x+ 30.40
Legend
¦ Salt Lake City
A Seattle
x Phoenix
Sterling Forest
* South Bronx
+ Hunter College
0 00
R =086
0 00 050 1 00 1 50
Mobile Sources l^g/m3)
y = -30 50x +22 13
R =064
0 00 0 10 0 20 030
Residual Oil Combustion (j^)/m3)
ouuu y = 7 58x +046
20 00 R =051
0 00 1 00 200 3 00
Wood Combustion (j^)/m3)
30 00 y = 2 24x + 14 31
10.00 -
0 00
20 00
10.00
0 00 1 00 2 00 3 00
Secondary Sulfate (p.g/m3)
0 50 1 00 1 50 2 00 2 50
Secondary Nitrate (p.g/m3)
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