PERCH Air Quality Study – PAQS Special thanks to Carl Mohrherr Alan Knowes Staff of OJSES FL-DOH...
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Transcript of PERCH Air Quality Study – PAQS Special thanks to Carl Mohrherr Alan Knowes Staff of OJSES FL-DOH...
PERCH Air Quality Study – PAQS
Special thanks toCarl MohrherrAlan Knowes
Staff of OJSESFL-DOHFL-DEP
SEARCH
Partnership forEnvironmentalResearch andCommunityHealth
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.
Pollutants at OJS and in the Region
40
20
0
pp
bv
NOy OJS PNS OLF
100806040200
Rain
(%t)
7/16/03 7/21/03 7/26/03 7/31/03 8/5/03 8/10/03 8/15/03Time (CST)
800600400200
pp
bv
CO OJS PNS OLF
40
20
0
µg
m-3
PM2.5 OJS ELY24h NVR24h PNS OLF
80604020
0
pp
bv
O3 OJS ELY NVR NAS WAR PNS OLF
20151050
pp
bv
SO2 OJS ELY UWF PNS OLF
0.00W
ind
Bar
bOJS
Diurnal Characteristics: Averages, Std.Dev.
5
4
3
2
1
0
m/s
WS15
10
5
0
pp
bv
SO2
50
40
30
20
10
0
pp
bv
O3
20
15
10
5
0
pp
bv
NOy
500
400
300
200
100
0
pp
bv
00:00 06:00 12:00 18:00 00:00Time (CST)
CO20
15
10
5
0
µg
/m3
00:00 06:00 12:00 18:00 00:00Time (CST)
PM2.5
OLF UWF ELY OJS PNS NAS NVR• Convective winds
• Sporadic SO2 events
• Bimodal CO and NOy
• Similar daytime O3 maxima at all sites
• Less nighttime O3 titration at NAS shoreline
• Trend to higher PM2.5 mass in southern part
1500
1000
500
0p
ptv
00:00 06:00 12:00 18:00 00:00Time (CST)
Isoprenen-Pentane
Air Toxics from VOC can samples
Halogenated HCsF-114 F-11
F-113CCl4
250
200
150
100
50
0
pp
tv
00:00 06:00 12:00 18:00 00:00Time (CST)
F11 F113F114CCl4
AromaticsBenzeneToluene
Ethylbenzenem-xylenep-xyleneo-xylene
1,3-butadiene 4-ethyltolene
1,3,5-trimethylbenzene1,2,4-trimethylbenzene
2000
1500
1000
500
0
B, T
, X (
pp
tv)
00:00 06:00 12:00 18:00 00:00Time (CST)
70
60
50
40
30
20
1,3
-Bu
tad
ien
e (p
ptv
)
BenzenesToluenesXylenes
AVG
STD
AVG
STD
0
10
20
30
40
50
60
70
VO
C M
R
(pp
bC
)
0
10
20
30
40
50
60
70
Diesel Exh. Gasoline Exh. Evap. Gasoline Refinery Fug. Primers & Enamel Biogenic Measured
VOC Source Apportionment via CMB8
0
10
20
30
40
50
60
70
80
90
100
7/18
/03
7:00
7/19
/03
12:0
0
7/19
/03
23:0
0
7/20
/03
12:0
0
7/20
/03
23:0
0
7/21
/03
11:0
0
7/21
/03
23:0
0
7/22
/03
12:0
0
7/22
/03
23:0
0
7/23
/03
12:0
0
7/23
/03
23:0
0
7/24
/03
12:0
0
7/24
/03
22:0
0
7/25
/03
12:0
0
7/25
/03
23:0
0
7/26
/03
12:0
0
7/26
/03
23:0
0
7/27
/03
12:0
0
7/27
/03
23:0
0
7/28
/03
12:0
0
7/28
/03
23:0
0
7/29
/03
12:0
0
7/29
/03
23:0
0
7/30
/03
11:0
0
7/30
/03
23:0
0
7/31
/03
12:0
0
7/31
/03
23:0
0
8/1/
03 1
2:22
8/1/
03 2
3:19
8/2/
03 1
2:08
8/2/
03 2
2:57
8/3/
03 1
2:17
8/3/
03 2
3:20
8/4/
03 1
2:05
8/4/
03 2
3:15
8/5/
03 1
2:18
8/5/
03 2
3:29
8/6/
03 1
2:32
8/8/
03 1
2:22
8/11
/03
12:3
0
8/11
/03
23:1
6
8/12
/03
12:0
4
8/12
/03
23:1
0
VO
C R
el. C
ontr
ibut
ion
(%
)
• 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).
32.9 28.8 31.5 29.7
34.432.7 32.2 39.3
10.811.0 9.1
9.0
15.918.3 17.1
19.7
3.6 7.4 7.80.4
2.4 1.8 2.3 1.90.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
7:00 12:00 17:00 23:00Time of Day (CST)
VO
C A
vg
Co
ntr
ibu
tio
n (
%)
0
10
20
30
40
50
60
70
80
90
100
Diesel Ex Gasoline Ex Evap Gasoline
Refinery Fug Primers & Enamel Biogenics
VOC Source Apportionment via CMB8
2.8 4.5 4.3 0.43.1 12.3 4.3 3.64.5 4.1 3.0 2.58.5 11.8 9.4 6.96.1 13.0 7.2 5.41.4 1.1 1.3 1.0
7:00 12:00 17:00 23:00
Standard Deviations
Transport from Local and Distant SourcesOzone (O3)
N
E
S
W22 44
ppbv
N
E
S
W22
ppbv 44
N
E
S
W22 44
ppbv
N
E
S
W22
ppbv 44
N
E
S
W22 44
ppbvN
E
S
W22 44
ppbvOJSWAR
NAS
NVR
OLF
ELY
N
E
S
W22 44
ppbvPNS
Transport from Local and Distant SourcesCarbon Monoxide (CO)
ELY
WAR
UWF
N
E
S
W
300
600ppbv
N
E
S
W
300
600ppbv
N
E
S
W
300
600ppbv
OJS
PNS
NAS
NVR
OLF
Transport from Local and Distant SourcesFine PM Mass (PM2.5)
NAS
NVR
N
E
S
W12 24
µg/m3
N
E
S
W12 24
µg/m3
N
E
S
W12 24
µg/m3N
E
S
W12
24
µg/m3
OJS
PNS
OLF ELY
Fine Particle Composition Monitor “PCM”
Reactive Gases
and PM2.5 SpeciesChannel 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”
3 programmable pumps with individual valves and mass flow
control in weather proof box
Sample air in
PCM Data Quality: Reactive Gases
Species NH3 SO2 HONO HNO3 HCl Acetic Formic Oxalic
DL (ppbv) 0.226 0.003 0.009 0.003 0.041 0.132 0.058 0.000D-eff (%) 100 100+-2 99+-2 99+-4 98+-6 97+-4 99+-2 100+-3
Reactive Gases
SO2 Comparison
y = 0.8529x - 0.0463
R2 = 0.9954
0
1
2
3
4
5
6
0 1 2 3 4 5 6 7
TEI average (ppbv)
PC
M d
en
ud
er
(pp
bv
)
PCM Results: Reactive Gases
0
1
2
3
4
5
6
Start Time (EST)
Rea
ctiv
e G
ases
(p
pb
v)
0
20
40
60
80
100
120
O3m
ax (
pp
bv)
NH3 HNO3 HONO HCl Acetic Formic Oxalic SO2 O3max
• 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.
PCM Results: PM2.5 Acidity
Net Acidity / Components of Acidity
-300
-200
-100
0
100
200
300
400
7/18/20
03 9:00
7/19/20
03 3:00
7/19/20
03 18:0
0
7/20/20
03 18:0
0
7/21/20
03 9:00
7/22/20
03 3:00
7/22/20
03 18:0
0
7/23/20
03 9:00
7/24/20
03 3:00
7/24/20
03 22:0
0
7/25/20
03 22:0
0
7/26/20
03 22:0
0
7/27/20
03 22:0
0
7/28/20
03 22:0
0
7/29/20
03 22:0
0
7/30/20
03 22:0
0
7/31/20
03 22:0
0
8/1/200
3 22:00
8/2/200
3 22:00
8/3/200
3 22:00
8/4/200
3 22:00
8/5/200
3 22:00
8/6/200
3 22:00
8/7/200
3 22:00
8/8/200
3 22:00
8/9/200
3 22:00
8/10/20
03 22:0
0
8/11/20
03 22:0
0
8/12/20
03 22:0
0AVG
Start Time (EST)
[ne
m-3
]
[SO4-2] [NO3-] [NH4+] Net Acidity
Charge balance shows high acidity towards dry period at end of campaign.
PCM Results: PM2.5 Mass and Composition
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
Start Time (EST)
Fra
ctio
n to
PM
2.5
0
10
20
30
40
50
PM
2.5
(m
g m
-3)
[SO4-2] [NO3-] [NH4+] Others EC LOA OC OOE.4 Un-ID
Sulfate fraction highest towards
end.
Average Composition
31%
2%
10%4%
27%
11%
11%2% 2%
Avg M = 14.6 +- 8.4 mg m-3
Uncertainty in Un-ID caused by uncertain EC and OC!
PCM Data Quality: PM2.5
Species Grav M SO4= Cl- NO3- Acetate Formate Oxalate NH4+ Na+ K+ Ca+
DL [mg m-3] 0.691 0.033 0.016 0.000 0.065 0.000 0.040 0.008 0.254 0.008 0.474incl Backup Filter 0.084 0.065 0.220 0.041 0.089
Mass Comparison
Ch1: y = 1.1761x - 2.5558
R2 = 0.9701
Ch2: y = 1.1153x - 1.2482
R2 = 0.9792
0
5
10
15
20
25
30
35
40
45
0 5 10 15 20 25 30 35 40
TEOM average (mg/m3)
PC
M T
eflo
n F
(m g
/m3)
PM2.5 Mass and Water-soluble Ions
Sulfate Comparison
y = 0.812x - 0.006
R2 = 0.990
0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25
PILS average (mg/m3)
PC
M T
efl
on
F (m g
/m3 )
PCM Data Quality: EC/OC
EC vs. CO Comparison
0.0
0.5
1.0
1.5
2.0
2.5
0 100 200 300 400 500 600 700
TEI CO average (mg/m3)P
CM
Qua
rtz
EC
(m g
/m3 )
Species EC OC SVOC
DL mg m-3 mg m-3 mg m-3
ASSE99 0.31 0.42 1.50FAQS2k_Mac 0.22 0.80 1.51FAQS2k_Aug 0.35 0.95 0.51FAQS2k_Col 0.34 0.71 0.66TexAQS2k_WT 0.59 0.93 0.51TexAQS2k_LP 0.42 0.80 0.51FAQS2001 0.68 0.83 0.60FAQS2002 0.11 0.45 0.47PBS2003 0.10 0.30 0.69PAQS2003 1.27 1.68 0.92
PM2.5 Elemental and Organic Carbon
Also, same punch analyses (precision): +- 50 % uncertainty (usually <10%)!!
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.
• 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)
Phase III Outlook
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 reactantsO3, OH, NO3, sunlight, acid catalysts
Mechanisms (with half hr to few hr yields):Gas-to-particle conversion/partitioning
e.g. terpene oxidationHeterogeneous reactions
aldehydes via hydration and polymerization, forming hemiacetal/acetal in presence of alcohols
Particle-phase reactionsacetal formation catalytically accelerated by particle sulfuric
acid (Jang and Kamens, ES&T, 2001)
Photochemical Processes Leading to O3 and PM
SOA
NOz
An Assessment of Tropospheric Ozone Pollution, A North American Perspective, NARSTO, National Acad. Press, 2000.
Atlanta JST Griffindownwind
120
100
80
60
40
20
0
O3
(
pp
bv
)
35302520151050
NOz (ppbv)
July 2001Sunny daytimesNortherly flowslope = 13.7 +-0.59intcept= 34 +-1.5r = 0.86incl "lost" HNO3
slope = 2.9 +-0.21intcept= 34 +-2.4r = 0.72
120
100
80
60
40
20
0
O3
(
pp
bv
)
35302520151050
NOz (ppbv)
Sunny daytimesAugust 1999slope = 3.6 +-0.14intcept= 59 +-1.5r = 0.59July 2001slope = 2.7 +-0.28intcept= 38 +-2.7r = 0.50December 2001slope = -0.6 +-0.09intcept= 33 +-1.1r = -0.42
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.
Photochemical ActivitySource – Receptor Considerations: O3/NOz as “OPE”
OPE Considerations for Pensacola 2003
00:00 03:00 06:00 09:00 12:00 15:00 18:00 21:00 00:00Time (CST)
80
60
40
20
0
O3
(pp
bv)
1086420NOz (ppbv)
slope = 7.9 +-0.7
PNS 80
60
40
20
0
O3
(pp
bv)
1086420NOz (ppbv)
slope = 7.8 +-0.5
OJS
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.