Prescribed Burning (PB) Impacts on Air Quality in the South-Eastern U.S.

Sponsors: DoD/EPA/State P2 Partnership,

USAIC, IMA-SERO

Karsten Baumann, Rick Saylor, Ben Hartsell, Eric Edgerton

Atmospheric Research & Analysis, Inc.

Contributors:

M. Clements, P. Gustafson, J. Greenlee, A. Braswell, D. Chan, K. Redmond,

J.B. Flanagan, S. Lee, M.E. Chang, A.G. Russell,

J.J. Schauer, L.P. Naeher, D.D. Blake

PB Benefits and Objectives

Reducing wildfire risk

Preparing sites for tree regeneration

Controlling disease and tree competition

Disposing of logging debris

Improving wildlife habitat

Improving understory forage for grazing

Enhancing aesthetics

Perpetuating fire-dependent species

Managing endangered species

BUT: PB is 3rd largest anthropogenic source of primary PM2.5

*

* EPA (2004), Air Quality Criteria for Particulate Matter, Fourth External Review Draft Report, EPA-600/P-99-002, aD, bD, Office of Research and Development, Research Triangle Park, NC, with data from http://www.epa.gov/ttn/chief/trends/.

** Wade D.D., B.L. Brock, P.H. Brose. J.B. Grace, G.A. Hoch, W.A. Patterson III, Chapter 4:53-96. In Brown J.K., Smith J.K. (Eds.): Wildland Fire in Ecosystems: Effects of Fire on Flora, Gen. Tech. Rep. RMRS-GTR-42-2 Ogden, UT. USDA-FS, Rocky Mountain Research Station, 2000.

…with > 8 million acres burned in SE-US mostly Jan-Jun.**

Conflict: Intensely Managed Areas Neighboring MSAs

Military Installations in SE-US are required to maintain ecosystem by

prescribed burning, risking violations of the NAAQS.

Clean Air Act

EndangeredSpecies Act

Most Army installations reside next to cities

subject to regulatory monitoring (MSA).

Reduction of daily PM2.5 NAAQS from 65 to

35 g m-3 will challenge most counties to

stay in compliance.

    Managed Nearest Popul.

Fort Area City 2000

    (acr)   Census

Benning GA 96,000 Columbus 186,000

Gordon GA 56,000 Augusta 195,000

Stewart GA 270,000 Savannah 132,000

Bragg NC 162,000 Fayetteville 121,000

Campbell TN 140,000 Clarksville 104,000

Jackson SC 52,000 Columbia 116,000

Rucker AL 63,000 Dothan/E.prise 70,000

Wang (GIT), Barnard (Mactec), et al., VISTAS Data Analysis, personal communication, 2006.

PB across South-Eastern U.S. in March 2002

Prescribed Burning (PB) in Georgia > 1,000,000 acres annually, majority in winter half

GRF

FAQS PeriodJul’00 - Sep’03

MAY - OCTNOV – APRJST Period

AUG’99

GRF

GRF

GRF

N

S

E W9 18

µgm-3

Macon 16.6 15.1

N

S

E W9 18

µgm-3

Augusta 16.2 14.0

N

S

E W9 18

µgm-3

16.6 18.4Columbus

N

S

E W9 18

µgm-317.3

13.5 Griffin

N

E

S

W18 36

µgm-3

JST 37.9

15

PM2.5 Wind Roses: Seasonal Differences Across GAIndications for Regional and Local Transport

Fall line Air Quality Study (FAQS), Final Report available via http://cure.eas.gatech.edu/faqs/index.html

SourceSource

SourceSource

ReceptorReceptor ReceptorReceptor

Air mass in 1 hr

Hourly incremented back-trajectory arriving at receptor site on 4/28 at 1500 EST and 500 m agl [Draxler & Rolph, 2003].

April 2004 Prescribed Burning Source - Receptor Field Study…to demonstrate procedures that directly link PB emissions with source impact areas.

Emission Profiles and Factors

Organic carbon (OC) is a dominant species of particulate emission, followed by EC and K. Enhanced emissions (2-3 orders > background) of Aromatics (benzene, toluene, xylenes), NH3

and Biogenics (isoprene, /-pinene), important precursors for formation of secondary PM. Emission Factors (EF) higher at smoldering than flaming; even more as C content increases.

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

g / k

g B

iom

ass

Fort Benning FL Fort Gordon FLFort Benning SM Fort Gordon SMAfrica_Woodland Africa_GrasslandPine_CA

x1000Gas

1.0E-071.0E-061.0E-051.0E-041.0E-031.0E-021.0E-011.0E+001.0E+011.0E+02

g /

kg B

iom

ass

PM

Lee et al., Environ. Sci. Technol. 39, 9049-9056, 2005

Different identified organic mass concentrations and fractions Different profile (different fuels, different combustion conditions)

Significant level of cholesterol seen only in “real world” emissions!

176 72.3 307 131

Open burning simulation comes closest

mg/g OC

Comparisons With Other Emission Studies

Fireplace

Lee et al., Environ. Sci. Technol. 39, 9049-9056, 2005

Fine PM Mass and Composition at Receptor Sites

Organic mass (OM = 1.6*OC) and sulfate are the major species of the measured ambient PM2.5 comprising more than 65% of its mass.

Ft. Benng. Jct., Columbus105 oN / 25 km from burn

Bungalow Rd., Augusta

250 oN / 20 km from burn

Lee et al., Environ. Sci. Technol. 39, 9049-9056, 2005

Ft. Benng. Jct., Columbus105 oN / 25 km from burn

Bungalow Rd., Augusta 250 oN / 20 km from burn

Motor vehicles and PB are major contributors to ambient [OC].

PB emissions contribute esp. during and immediately after the burns.

Large unexplained fraction during (+after) regional rain events, possibly due to SOA? Needs further investigation!

CMB Receptor ModelingOrganic Carbon (OC) Source Apportionment at Receptors

rain

Lee et al., Environ. Sci. Technol. 39, 9049-9056, 2005

Importance of direct (primary) and indirect (secondary) emissions: How fast are they formed?

VOCs

PMNOx

O3

SOAOthers

Toxics

COCO2

Fort Benning 400 acr PB from ca. 4 miles away

PMF Receptor Modeling in Urban SE-US Using STNPM2.5 Factor Contributions at Birmingham, AL

33.6

33.5

33.4

-87.0 -86.9 -86.8 -86.7 -86.6

Birmingham

CFPP COKE METL1 METL2 MINEP CHEM OTHER

5 x 5 km

AL-78

I-65

I-59

I-20

I-65

I-59/20

AL-280

Airport

500

400

300

200

100

0

PM

2.5

Em

issi

on

s (t

py)

N

E

S

W24 % 48

sSO4 MVEHIND SOC BB

N

E

S

W15 30

PM2.5

(µg m-3

)

Similarities between Biomass Burning and SOC contributions

Baumann et al., JAWMA 58, 27-44, 2008

PMF Receptor Modeling in Rural SE-US Using SEARCHPM2.5 Factor Contributions in Q1 vs.

Baumann et al., JAWMA submitted, 2008

N

E

S

W28 56

YRK

N

E

S

W28 56

OAK

Secondary sulfate factor has more regional character with higher FCE in Q3. Prescribed burning factor has more local features with higher FCE in Q1. YRK least rural and influenced by ATL air shed.

Q3

N

E

S

W28 56

Freq.(%)

PM2.5 (µg m-3)

sSO4 (%) BB (%)

CTR

34

32

30

-90 -88 -86 -84 -82

50 x 50 km

1/25

2/6

N

E

S

W28 56

N

E

S

W28 56

N

E

S

W28 56

Freq.(%)

PM2.5 (µg m-3

)

sSO4 (%) BB (%)

YRK

CTR

OAK

34

32

30

-90 -88 -86 -84 -82

50 x 50 km

OAK

CTR

YRK

1/25

2/6

1/28 w/strong rain

2/3

w/li

gh

t ra

in

1/31 w/light rain

2005

160

120

80

40

0

SO

2 E

mis

sion

s (k

tpy)

1/17 1/21 1/25 1/29 2/2 2/6 2/10 2/14

PMF Receptor Modeling in Rural SE-US Using SEARCHDistribution of Major Precursor Sources: SO2

* and OVOC**

* EPA, Technology Transfer Network, Clearinghouse for Inventories & Emissions Factors, 2002 National Emissions Inventory Data & Documentation,

accessible via http://www.epa.gov/ttn/chief/net/2002inventory.html#inventorydata.

** NOAA National Environmental Satellite, Data, and Information Service (NESDIS) with 2005 data extracted from the National

Geophysical Data Center (NGDC) via http://map.ngdc.noaa.gov/website/firedetects/viewer.htm.

PMF Receptor Modeling in Rural SE-US Using SEARCHPM2.5 Daily Source Contributions in Jan-Feb 2005 at OAK

Baumann et al., JAWMA submitted, 2008

1/25 and 2/6 2005 saw highest and second highest PM2.5 and OC concentrations at OAK.

In both events PB contributions dominate both PM2.5 and OC concentrations.

Sulfate and sSO4 contributions are low during 1st and high during 2nd event. Fraction of sulfate neutralized in NH4

+-NO3- milieu is 78 and 87 % during 1st and 2nd event, respectively.

OM/OC ratio is ~1.4 during 1st and ~1.8 during 2nd event. Arrival of mostly rural air mass from W on 1/25 vs. urban/SO2 influenced air mass from E on 2/6.

Do OOE on 2/6 contain S (e.g. in form of organosulfates per Surratt et al., 2008)? SOA formation indicated by un-apportioned OC, OC/EC and SOC/OC, peaks during both events. Back-trajectories and on-site observations suggest fast (few h) SOA formation in PB plumes.

140

120

100

80

60

40

20

0

PM

2.5

(µ

g m

-3)

1/17 1/21 1/25 1/29 2/2 2/6 2/10 2/14Time (CST)

FRMSCE for orig. OC

UnID BB DUST IND MIX MOB sSO4

80

60

40

20

0

OC

(µ

g m

-3)

SO

C/O

C (

%)

1/19 1/29 2/8

Time (CST)

8

6

4

2

0

OC

/EC

(-) OM

/OC

(-)

SCE for subs. OC SOC/OC OC/EC OM/OC

140

120

100

80

60

40

20

0

PM

2.5

(µ

g m

-3)

1/17 1/21 1/25 1/29 2/2 2/6 2/10 2/14Time (CST)

Measured FRM OOE OC EC OtherID MMO PBW NH4 NO3 SO4

Main Conclusions

PB is a regional source with local impacts on rural receptors.

DoD is most sensitive to PB application due to civilian encroachment

(opportunity to test alternative land management practices?).

Both CMB and PMF yield significant contributions from a

source/factor resembling PB to receptor [PM2.5] and [OC].

PMF plausibly reflects lower BB-FCE in urban environs (BHM), while

higher BB-FCE are obtained in rural environs (CTR, OAK).

Rural receptors see highest BB-FCE during highest PB activity (Q1).

Reactive PB emissions suggest rapid SOA formation as indicated by

OAK case study (being further investigated).