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.