Transcript PERCH Air Quality Study - Georgia Institute of Technology

PERCH Air Quality Study – PAQS
Partnership for
Environmental
Research and
Community
Health
Special thanks to
Carl Mohrherr
Alan Knowes
Staff of OJSES
FL-DOH
FL-DEP
SEARCH
PERCH Air Quality Study – Phase II
 Scope: air toxics, ozone, and particulate matter.
 Identify, compile, and assess existing emissions and ambient air
data from US EPA, FL DEP, and private (e.g. SEARCH).
 Review existing studies (particularly National Air Toxics
Assessment and Gulf Coast Ozone Study). Any gaps?
 Complete a health impacts literature search.
 Screen for potential health risks due to realized and potential
ambient exposures.
Design and conduct field pilot study.
Phase II Findings Reported at Meetings on
11/3/03 and 12/8/03,
and in Quarterly Reports Nov’03 and Feb’04.
Wind Barb
Pollutants at OJS and in the Region
ppbv
ppbv
ppbv
0.00
OJS
20
15
10
5
0
80
60
40
20
0
SO2 OJS ELY UWF PNS OLF
O3 OJS ELY NVR NAS WAR PNS OLF
NOy OJS PNS OLF
40
20
PM2.5 OJS ELY24h NVR24h PNS OLF
40
20
0
800
600
400
200
CO OJS PNS OLF
7/16/03
7/21/03
7/26/03
7/31/03
Time (CST)
8/5/03
8/10/03
100
80
60
40
20
0
8/15/03
Rain (%t)
ppbv
µgm
-3
0
Diurnal Characteristics: Averages, Std.Dev.
OLF UWF ELY OJS PNS NAS NVR
5
• Convective winds
15
WS
SO2
4
• Sporadic SO2 events
3
ppbv
m/s
10
2
• Bimodal CO and NOy
5
• Similar daytime O3
maxima at all sites
1
0
20
0
50
NOy
O3
40
• Less nighttime O3 titration
at NAS shoreline
ppbv
ppbv
15
10
5
20
• Trend to higher PM2.5
mass in southern part
10
0
500
30
0
20
CO
PM2.5
1500
15
Isoprene
n-Pentane
300
pptv
3
µg/m
ppbv
400
10
1000
200
500
5
100
0
00:00
06:00
12:00
Time (CST)
18:00
00:00
0
00:00
06:00
12:00
Time (CST)
18:00
00:00
0
00:00
06:00
12:00
Time (CST)
18:00
00:00
Air Toxics from VOC can samples
250
Halogenated HCs
pptv
F-114
F-11
F-113
CCl4
F11
F113
F114
CCl4
200
150
AVG
100
50
0
00:00
06:00
Aromatics
B, T, X (pptv)
2000
1500
00:00
70
Benzenes
Toluenes
Xylenes
AVG
60
50
1000
40
STD
500
30
20
0
00:00
06:00
12:00
Time (CST)
18:00
00:00
1,3-Butadiene (pptv)
Benzene
Toluene
Ethylbenzene
m-xylene
p-xylene
o-xylene
1,3-butadiene
4-ethyltolene
1,3,5-trimethylbenzene
1,2,4-trimethylbenzene
12:00
Time (CST)
STD
18:00
7/18/03 7:00
0
8/12/03 23:10
8/12/03 12:04
8/11/03 23:16
8/11/03 12:30
Biogenic
8/8/03 12:22
8/6/03 12:32
8/5/03 23:29
8/5/03 12:18
Primers & Enamel
8/4/03 23:15
8/4/03 12:05
8/3/03 23:20
8/3/03 12:17
8/2/03 22:57
8/2/03 12:08
8/1/03 23:19
8/1/03 12:22
Refinery Fug.
7/31/03 23:00
7/31/03 12:00
7/30/03 23:00
7/30/03 11:00
7/29/03 23:00
7/29/03 12:00
Evap. Gasoline
7/28/03 23:00
7/28/03 12:00
7/27/03 23:00
7/27/03 12:00
7/26/03 23:00
7/26/03 12:00
Gasoline Exh.
7/25/03 23:00
7/25/03 12:00
7/24/03 22:00
7/24/03 12:00
7/23/03 23:00
7/23/03 12:00
VOC MR (ppbC)
Diesel Exh.
7/22/03 23:00
7/22/03 12:00
7/21/03 23:00
7/21/03 11:00
7/20/03 23:00
7/20/03 12:00
7/19/03 23:00
7/19/03 12:00
VOC Rel. Contribution (%)
VOC Source Apportionment via CMB8
70
70
Measured
60
60
50
50
40
40
30
30
20
20
10
10
0
0
100
90
80
70
60
50
40
30
20
10
VOC Source Apportionment via CMB8
Diesel Ex
Refinery Fug
3.6
0.9
15.9
VOC Avg Contribution (%)
1.0
0.8
Gasoline Ex
Primers & Enamel
7.4
18.3
10.8
0.7
11.0
Evap Gasoline
Biogenics
7.8
0.4
100
19.7
90
17.1
9.1
9.0
70
0.6
0.5
80
34.4
32.7
32.2
39.3
50
0.4
40
0.3
30
0.2
0.1
Standard Deviations
60
32.9
2.4
28.8
31.5
29.7
1.8
2.3
1.9
0.0
20
10
0
7:00
12:00
17:00
23:00
2.8
3.1
4.5
8.5
6.1
1.4
4.5
12.3
4.1
11.8
13.0
1.1
4.3
4.3
3.0
9.4
7.2
1.3
0.4
3.6
2.5
6.9
5.4
1.0
7:00
12:00
17:00
23:00
Time of Day (CST)
• Gasoline related sources were dominant contributors (combined ~ 65 %), followed
by primers and enamel, refinery fugitives, biogenics, and diesel exhaust.
• Trend to higher biogenic contributions during daytime.
• Trend to higher gasoline contributions during nighttime and early morning.
• Similarities to air toxics (aromatics).
Transport from Local and Distant Sources
Ozone (O3)
N
N
ppbv
44
W
OLF
ELY
E
22
W
22
N
E
44
ppbv
N S
N
S
W
W
22
WAR
22
E
44
ppbv
S
OJS
N
W
22
E
44
ppbv
PNS
N
S
W
44
ppbv
S
W
E
44
ppbv
22
NVR
ppbv
44
NAS
S
22
E
S
E
Transport from Local and Distant Sources
Carbon Monoxide (CO)
N
OLF
W
UWF
E
300
600
ppbv
ELY
N
S
OJS
N
W
E
300
PNS
W
600
ppbv
E
300
WAR S
NAS
600
ppbv
S
NVR
Transport from Local and Distant Sources
Fine PM Mass (PM2.5)
N
N
W
OLF
12
ELY
E
24
3
µg/m
W
E
12
24
3
µg/m
N
S
N
S
12
W
W
PNS
12
S
NAS
OJS
E
24
3
µg/m
E
24
3
µg/m
S
NVR
Fine Particle Composition Monitor “PCM”
3 programmable pumps with
individual valves and mass flow
control in weather proof box
Reactive Gases
and PM2.5 Species
Channel 1:
NH3
Na+, K+, NH4+, Ca+2
Channel 2:
HF, HCl, HONO, HNO3, SO2,
HCOOH, CH3COOH, (COOH)2
F-, Cl-, NO3-, SO4=,
HCOO-, CH3COO-, C2O4=
Channel 3:
EC, OC, “SVOC”
Sample air in
PCM Data Quality: Reactive Gases
Species
NH3
SO2
HONO
HNO3
HCl
Acetic
Formic
Oxalic
DL (ppbv)
D-eff (%)
0.226
100
0.003
100+-2
0.009
99+-2
0.003
99+-4
0.041
98+-6
0.132
97+-4
0.058
99+-2
0.000
100+-3
SO2 Comparison
6
PCM denuder (ppbv)
5
y = 0.8529x - 0.0463
R2 = 0.9954
4
3
2
1
0
0
1
2
3
4
TEI average (ppbv)
 Reactive Gases
5
6
7
PCM Results: Reactive Gases
• NH3 systematically lower at daytime (0.6 +-.2 ppbv) than nighttime (0.8 +-.3 ppbv).
• Formic and Acetic track closely, higher during day than night, indicating microbial
soil (T) and photochemical atmospheric sources (esp. dry period at end).
• HNO3 tracks with O3, maximum at day, and towards high O3 (and PM2.5) period at
end, pointing to photochemical source.
A
V
7/
18
/2
00
7/
3
9:
19
00
/2
0
7/
0
3
19
3
/2
0 0 :00
3
7/
18
20
:
/2
00 00
3
7/
21 1 8:
0
/2
00 0
7/
3
9:
22
00
/2
0
7/
22 03 3
/2
0 0 :00
3
7/
23 1 8:0
/2
00 0
7/
3
9:
24
0
/2
00 0
7/
3
24
3
/2
0 0 :00
7/
3
22
25
:
/2
00 00
3
7/
22
26
:
/2
00 00
7/
3
22
27
:
/2
00 00
7/
3
22
28
:
/2
00 00
7/
3
22
29
:
/2
00 00
3
7/
2
30
2:
/2
00 00
7/
3
22
31
:
/2
00 00
3
8/
2
1/
2:
20
0
03 0
8/
22
2/
:0
20
03 0
8/
22
3/
:0
20
03 0
8/
22
4/
:0
20
03 0
8/
22
5/
:0
20
03 0
8/
2
2:
6/
20
0
03 0
8/
22
7/
:0
20
03 0
8/
22
8/
:0
20
03 0
8/
22
9/
:0
20
0
0
8/
3
10
22
/2
0 0 :00
3
8/
22
11
:
/2
00 00
8/
3
22
12
:
/2
00 00
3
22
:0
0
G
-3
[ne m ]
PCM Results: PM2.5 Acidity
Net Acidity / Components of Acidity
[SO4-2] [NO3-] [NH4+] Net Acidity
400
300
200
100
0
-100
-200
-300
Start Time (EST)
Charge balance shows high acidity towards dry period at end of campaign.
PCM Results: PM2.5 Mass and Composition
[SO4-2]
[NO3-]
[NH4+]
Others
EC
LOA
OC
OOE.4
Un-ID
50
Sulfate
fraction
highest
towards
end.
-3
PM2.5 (m g m )
40
30
20
10
0
Average Composition
11%
2%
2%
31%
11%
2%
27%
10%
4%
Avg M = 14.6 +- 8.4 m g m-3
Uncertainty in Un-ID caused by uncertain EC and OC!
PCM Data Quality: PM2.5
Species
Grav M
-3
DL [mg m ]
0.691
incl Backup Filter
SO4=
Cl-
NO3-
Acetate
0.033
0.016
0.000
0.084
0.065
0.065
Formate Oxalate
0.000
0.220
0.040
0.041
Mass Comparison
Na+
K+
Ca+
0.008
0.089
0.254
0.008
0.474
Sulfate Comparison
45
20
40
18
16
35
Ch1: y = 1.1761x - 2.5558
R2 = 0.9701
30
PCM Teflon F (mg/m3)
PCM Teflon F (mg/m3)
NH4+
25
20
Ch2: y = 1.1153x - 1.2482
R2 = 0.9792
15
10
y = 0.812x - 0.006
R2 = 0.990
14
12
10
8
6
4
5
2
0
0
5
10
15
20
25
30
3
TEOM average (mg/m )
35
40
0
0
5
10
15
20
3
PILS average (mg/m )
 PM2.5 Mass and Water-soluble Ions
25
PCM Data Quality: EC/OC
EC vs. CO Comparison
DL
ASSE99
FAQS2k_Mac
FAQS2k_Aug
FAQS2k_Col
TexAQS2k_WT
TexAQS2k_LP
FAQS2001
FAQS2002
PBS2003
PAQS2003
EC
-3
mg m
0.31
0.22
0.35
0.34
0.59
0.42
0.68
0.11
0.10
1.27
OC
-3
mg m
0.42
0.80
0.95
0.71
0.93
0.80
0.83
0.45
0.30
1.68
SVOC
-3
mg m
1.50
1.51
0.51
0.66
0.51
0.51
0.60
0.47
0.69
0.92
2.5
PCM Quartz EC (mg/m3)
Species
2.0
1.5
1.0
0.5
0.0
0
100
200
300
400
500
3
TEI CO average (mg/m )
Also, same punch analyses (precision): +- 50 % uncertainty (usually <10%)!!
PM2.5 Elemental and Organic Carbon
600
70
Phase II Findings
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Period 7/15-8/14 characterized by frequent precipitation.
Period has been unseasonably wet for SE-US.
Leading to low [O3] and [PM2.5] region-wide.
Land-sea breeze circulation most prominent at shore sites.
Sea breeze (southerly flow) converging with westerlies on middays.
Highest [O3] associated with southerly component flow at all sites.
Highest [PM2.5] with continental air mass during dry period at end.
OJS predominantly influenced by mobile sources (CO, NOy).
Sporadic SO2 events during morning BL evolution.
Gasoline related sources largest contributor to total measured VOC,
highest at night and early morning.
Biogenic VOC contribute most (8 +-4 %) during daytime.
High O3 and PM2.5 event associated with highest HNO3 and LOA.
Formic and Acetic track closely, higher during day, indicating microbial
soil (T) and photochemical atmospheric sources.
NH3 systematically higher at night, early a.m.  mobile sources?
Highest SO4= mass fraction and acidity during high PM period.
Large (>40%) but uncertain organics fraction, plus highly uncertain EC,
due to hidden instabilities in TOT laser intensity and T controls.
Phase III Outlook
• Improve EC and OC data quality by reanalysis.
• Integrate and comprehensively evaluate regional PM2.5 mass and
composition data (incl. FLDEP, ADEM, GAEPD, SEARCH).
• Characterize air mass history from regionally elevated PM episode
i.t.o. transport (back-trajectories) and chemical transformation;
apply Lagrange box model, emissions, and STN observations.
• Identify origin and primary sources (distant but large wild fires?) for
regional pollution.
• Estimate P(O3)/OPE and evaluate in conjunction with OM/OC
estimates and relative OC fractions evolving at different T, to
constrain OC oxidation state.
• Assess fraction of Secondary Organic Aerosol (SOA) from EC tracer
method (OC/EC ratio).
• Develop selection criteria for primary EC/OC considering measured
photochemical products (O3, HNO3, NOz/NOy) and primary source
indicators (CO, SO2, NOy and ratios)
Secondary organic aerosol (SOA):
Organic compounds, some highly oxygenated, residing in the
aerosol phase as a function of atmospheric reactions that
occur in either gas or particle phases.
SOA formation mainly depends on:
Emissions & forming potential of precursors
aromatics (BTX, aldehydes, carbonyls)
terpenes (mono-, sesqui-)
other biogenics (aldehydes, alcohols)
Presence of other initiating reactants
O3, OH, NO3, sunlight, acid catalysts
Mechanisms (with half hr to few hr yields):
Gas-to-particle conversion/partitioning
e.g. terpene oxidation
Heterogeneous reactions
aldehydes via hydration and polymerization, forming
hemiacetal/acetal in presence of alcohols
Particle-phase reactions
acetal formation catalytically accelerated by particle sulfuric
acid (Jang and Kamens, ES&T, 2001)
Photochemical Processes Leading to O3 and PM
An Assessment of Tropospheric Ozone Pollution, A North American Perspective, NARSTO, National Acad. Press, 2000.
NOz
SOA
Photochemical Activity
Source – Receptor Considerations: O3/NOz as “OPE”
downwind
Atlanta JST
Griffin
120
120
Sunny daytimes
August 1999
100
slope = 3.6 +-0.14
intcept= 59 +-1.5
r = 0.59
80
July 2001
slope = 2.7 +-0.28
intcept= 38 +-2.7
r = 0.50
December 2001
60
40
slope = -0.6 +-0.09
intcept= 33 +-1.1
r = -0.42
20
O3 (ppbv)
O3 (ppbv)
100
July 2001
Sunny daytimes
Northerly flow
slope = 13.7 +-0.59
intcept= 34 +-1.5
r = 0.86
incl "lost" HNO3
slope = 2.9 +-0.21
intcept= 34 +-2.4
r = 0.72
80
60
40
20
0
0
0
5
10
15
20
NOz (ppbv)
25
30
35
0
5
10
15
20
25
30
35
NOz (ppbv)
Elevated regional O3 background reflected in regression’s intercept: higher in Aug 99!
At JST higher intercept and slope during Aug ’99 (OPE= 4 vs 3): more efficient P(O3).
OPE in air mass arriving at Griffin is likely larger given by upper and lower limits.
Lower limit assumes 1st order loss of HNO3 due to surface deposition at k ≈ 0.22 h-1.
Air mass transitions from VOC-limited to NOx-limited regime due to Biogenic HC.
High photochemical activity P(O3) allows for high P(SOA): rural/urban gradient.
OPE Considerations for Pensacola 2003
00:00
03:00
06:00
09:00 12:00 15:00
Time (CST)
PNS
80
18:00
21:00
00:00
OJS
80
slope = 7.8 +-0.5
60
O3 (ppbv)
O3 (ppbv)
slope = 7.9 +-0.7
40
60
40
20
20
0
0
0
2
4
6
NOz (ppbv)
8
10
0
2
4
6
NOz (ppbv)
8
Crude midday OPE is very similar for both sites, indicating moderate OPE.
Intercept indicating relatively low background O3 level.
A much more refined analysis is required for true OPE.
High PM2.5/O3 case study: Compare on temporal and spatial basis.
10