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 3 rd largest anthropogenic source of primary PM 2.5 * * EPA (2004), Air Quality Criteria for Particulate Matter, Fourth External Review Draft Report, EPA-600/P , aD, bD, Office of Research and Development, Research Triangle Park, NC, with data from ** Wade D.D., B.L. Brock, P.H. Brose. J.B. Grace, G.A. Hoch, W.A. Patterson III, Chapter 4: 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, …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 Endangered Species Act Most Army installations reside next to cities subject to regulatory monitoring (MSA). Reduction of daily PM 2.5 NAAQS from 65 to 35  g m -3 will challenge most counties to stay in compliance. ManagedNearestPopul. FortAreaCity2000 (acr) Census BenningGA96,000Columbus186,000 GordonGA56,000Augusta195,000 StewartGA270,000Savannah132,000 BraggNC162,000Fayetteville121,000 CampbellTN140,000Clarksville104,000 JacksonSC52,000Columbia116,000 RuckerAL63,000Dothan/E.prise70,000

Wang (GIT), Barnard (Mactec), et al., VISTAS Data Analysis, personal communication, 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 Period Jul’00 - Sep’03 MAY - OCT NOV – APR JST Period AUG’99 GRF PM 2.5 Wind Roses: Seasonal Differences Across GA Indications for Regional and Local Transport Fall line Air Quality Study (FAQS), Final Report available via

Source Source Receptor Receptor 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), NH 3 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. x1000 Gas PM Lee et al., Environ. Sci. Technol. 39, , 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! Open burning simulation comes closest mg/g OC Comparisons With Other Emission Studies Fireplace Lee et al., Environ. Sci. Technol. 39, , 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 PM 2.5 comprising more than 65% of its mass. Ft. Benng. Jct., Columbus 105 o N / 25 km from burn Bungalow Rd., Augusta 250 o N / 20 km from burn Lee et al., Environ. Sci. Technol. 39, , 2005

Ft. Benng. Jct., Columbus 105 o N / 25 km from burn Bungalow Rd., Augusta 250 o N / 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 Modeling Organic Carbon (OC) Source Apportionment at Receptors rain Lee et al., Environ. Sci. Technol. 39, , 2005

Importance of direct (primary) and indirect (secondary) emissions: How fast are they formed? VOCs PM NOx O 3 SOA Others Toxics CO CO 2

Fort Benning 400 acr PB from ca. 4 miles away

PMF Receptor Modeling in Urban SE-US Using STN PM 2.5 Factor Contributions at Birmingham, AL Similarities between Biomass Burning and SOC contributions Baumann et al., JAWMA 58, 27-44, 2008

PMF Receptor Modeling in Rural SE-US Using SEARCH PM 2.5 Factor Contributions in Q1 vs. Baumann et al., JAWMA submitted, 2008  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 YRK CTR OAK

PMF Receptor Modeling in Rural SE-US Using SEARCH Distribution of Major Precursor Sources: SO 2 * and OVOC ** * EPA, Technology Transfer Network, Clearinghouse for Inventories & Emissions Factors, 2002 National Emissions Inventory Data & Documentation, accessible via ** NOAA National Environmental Satellite, Data, and Information Service (NESDIS) with 2005 data extracted from the National Geophysical Data Center (NGDC) via

PMF Receptor Modeling in Rural SE-US Using SEARCH PM 2.5 Daily Source Contributions in Jan-Feb 2005 at OAK Baumann et al., JAWMA submitted, 2008  1/25 and 2/ saw highest and second highest PM 2.5 and OC concentrations at OAK.  In both events PB contributions dominate both PM 2.5 and OC concentrations.  Sulfate and sSO4 contributions are low during 1 st and high during 2 nd event.  Fraction of sulfate neutralized in NH 4 + -NO 3 - milieu is 78 and 87 % during 1 st and 2 nd event, respectively.  OM/OC ratio is ~1.4 during 1 st and ~1.8 during 2 nd event.  Arrival of mostly rural air mass from W on 1/25 vs. urban/SO 2 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.

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 [PM 2.5 ] 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).