Prescribed Burning PB Impacts on Air Quality in
Prescribed Burning (PB) Impacts on Air Quality in the South-Eastern U. S. Sponsors: Do. D/EPA/State P 2 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* …with > 8 million acres burned in SE-US mostly Jan-Jun. ** * EPA (2004), Air Quality Criteria for Particulate Matter, Fourth External Review Draft Report, EPA-600/P-99 -002, a. D, b. D, 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.
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 mg m-3 will challenge most counties to stay in compliance. Managed Nearest Popul. 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 Fort
PB across South-Eastern U. S. in March 2002 Wang (GIT), Barnard (Mactec), et al. , VISTAS Data Analysis, personal communication, 2006.
Prescribed Burning (PB) in Georgia > 1, 000 acres annually, majority in winter half
PM 2. 5 Wind Roses: Seasonal Differences Across GA Indications for Regional and Local Transport GRF GRF FAQS Period Jul’ 00 - Sep’ 03 MAY - OCT NOV – APR JST Period AUG’ 99 Fall line Air Quality Study (FAQS), Final Report available via http: //cure. eas. gatech. edu/faqs/index. html
April 2004 Prescribed Burning Source - Receptor Field Study …to demonstrate procedures that directly link PB emissions with source impact areas. Source 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].
Emission Profiles and Factors PM Gas x 1000 ü Organic carbon (OC) is a dominant species of particulate emission, followed by EC and K. ü Enhanced emissions (2 -3 orders > background) of Aromatics (benzene, toluene, xylenes), NH 3 and Biogenics (isoprene, a-/b-pinene), important precursors formation of secondary PM. ü Emission Factors (EF) higher at smoldering than flaming; even more as C content increases. Lee et al. , Environ. Sci. Technol. 39, 9049 -9056, 2005
Comparisons With Other Emission Studies ü Different identified organic mass concentrations and fractions ü Different profile (different fuels, different combustion conditions) ü Significant level of cholesterol seen only in “real world” emissions! 176 72. 3 307 131 mg/g OC Open burning simulation comes closest Fireplace Lee et al. , Environ. Sci. Technol. 39, 9049 -9056, 2005
Fine PM Mass and Composition at Receptor Sites Bungalow Rd. , Augusta Ft. Benng. Jct. , Columbus 250 o. N / 20 km from burn 105 o. N / 25 km from burn ü 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. Lee et al. , Environ. Sci. Technol. 39, 9049 -9056, 2005
CMB Receptor Modeling Organic Carbon (OC) Source Apportionment at Receptors Bungalow Rd. , Augusta 250 o. N / 20 km from burn Ft. Benng. Jct. , Columbus 105 o. N / 25 km from burn rain ü Motor vehicles and PB are major contributors to ambient [OC]. ü PB emissions contribute esp. during and immediately after the burns. ü Large unexplained fraction during (+after) regional rain events, possibly due to SOA? Needs further investigation! Lee et al. , Environ. Sci. Technol. 39, 9049 -9056, 2005
Importance of direct (primary) and indirect (secondary) emissions: How fast are they formed? CO CO 2 O 3 SOA Others VOCs Toxics NOx PM
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 Q 1 vs. Q 3 YRK CTR OAK ¤ Secondary sulfate factor has more regional character with higher FCE in Q 3. ¤ Prescribed burning factor has more local features with higher FCE in Q 1. ¤ YRK least rural and influenced by ATL air shed. Baumann et al. , JAWMA submitted, 2008
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 http: //www. epa. gov/ttn/chief/net/2002 inventory. 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 SEARCH PM 2. 5 Daily Source Contributions in Jan-Feb 2005 at OAK ¤ ¤ ¤ ¤ ¤ 1/25 and 2/6 2005 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 s. SO 4 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. Baumann et al. , JAWMA submitted, 2008
Main Conclusions PB is a regional source with local impacts on rural receptors. Do. D 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 (Q 1). Reactive PB emissions suggest rapid SOA formation as indicated by OAK case study (being further investigated).
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