Karsten Baumann Senior Research Engineer D.S. Ensor, Center for Aerosol Technology (CAT)

1. RTI International is a trade name of Research Triangle Institute 3040 Cornwallis Road ■ P.O. Box 12194 ■ Research Triangle Park, North Carolina, USA 27709 Phone (919) 485-2660 Fax (919) 541-6936 e-mail kb@rti.org Air Quality Impacts from Prescribed Burning (PB) Karsten Baumann Senior Research Engineer D.S. Ensor, Center for Aerosol Technology (CAT) C.E. Rodes, Aerosol Technology and Environmental Exposure Program (ATEEP) Communication May 4, 2006

2. Contributions of PB Emissions to Ambient PM2.5Challenges and Opportunities for Air Quality Management Sponsored by: DoD/EPA/State P2 Partnership, USAIC Fort Benning, IMA-SERO Fort McPherson, Georgia Contributors: S. Lee, K. Manomaiphiboon, M.E. Chang, A.G. Russell, M. Zheng, J.J. Schauer, L.P. Naeher, D.D. Blake, M. Clements, P. Gustafson, J. Greenlee, A. Braswell, D. Chan, K. Redmond Communication

3. Introduction • Forest fires (wildfires & prescribed fires) are a significant source for primary PM2.5 in Georgia and the South-Eastern United States. • Prescribed Burning (PB) is the primary land management tool for the benefit of forest ecosystem, endangered species, and DOD’s mission. • PM emissions have not been well characterized, esp. Particulate Organic Compounds (POC) in PM2.5 and their impact on air quality. • Pilot Study in April 2004 demonstrated simultaneous measurements of in situ PB emissions and [PM2.5] at regulatory monitoring sites. • CMB receptor model shown to be valid tool for estimating PB source contribution to ambient [PM2.5] in local impact areas. • Opportunities and needs for future collaborations on development of proper tools and methodologies are presented. Communication

4. Motivation: PB is 3rd largest anthropogenic source of primary PM2.5[EPA, 2004] 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/. Communication

5. More Motivation: Proposed Revision of PM2.5 NAAQS[EPA, 2005] Distribution of annual mean [PM2.5] and [PM10-2.5] for 2001-03 period with inter-quartile range and median (box), 5th and 95th percentiles (whiskers), minima and maxima (*). Reduction of annual PM2.5 NAAQS from 15 to 12 mg m-3 would put most of the Southeast and many other regions out of compliance. EPA (2005), Review of the National Ambient Air Quality Standards for Particulate Matter: Policy Assessment of Scientific and Technical Information, OAQPS, EPA-452/R-05-005, June 2005 (www.epa.gov/ttn/naaqs/standards/pm/data/pmstaffpaper_20050630.pdf). Communication

6. Endangered Species Act Clean Air Act Problem: Intensively Managed Areas Neighboring MSAs Military Installations in SE-US are required to maintain ecosystem by prescribed burning, risking violations of the NAAQS. Most Army installations reside next to cities subject to regulatory monitoring (MSA). Proposed reduction of annual PM2.5 NAAQS from 15 to 12 mg m-3 puts even more counties out of compliance !! Communication

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

8. Prescribed Burning in Georgia> 1,000,000 acres annually, majority in winter half Communication

9. GRF GRF OLC FAQS Period Jul’00 - Sep’03 MAY - OCT NOV – APR JST Period AUG’99 GRF GRF PM2.5 Wind Roses: Seasonal Differences Across GAIndications for Regional and Local Transport Communication

10. Ft. Benning burning 1,000 acres adds ~2 mg m-3 to PM at OLC. Local Source Benning – Receptor OLC Relationship PCA-Regression Results for Daily Data Aug-01 to Sep-03 Communication

11. 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. Communication

12. PM Gas x1000 Emission Factors in g/kg Biomass ΔX: excess mass concentration ΔC: excess carbon concentration NMHC : non-methane hydrocarbons PC : particulate carbon Assume Biomass-C = 42.6% [Hays et al., 2002] • 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, a-/b-pinene), important precursors for formation of secondary PM. • Emission Factors (EF) higher at smoldering than flaming; even more as C content increases. • Smoldering EF in g/kg biomass mostly higher relative to other studies. Communication

13. 176 72.3 131 mg/g OC 307 Open burning simulation comes closest Comparisons With Other Emission Studies • Different identified organic mass concentrations and fractions • Different profile (different fuels, different combustion conditions) • Significant level of cholesterol seen only in “real world” emissions!! Fireplace Lee et al., Environ. Sci. Technol., 2005 Communication

14. Ambient Conditions at EPD Receptor Sites in April 2004 Bungalow Rd., Augusta Ft. Benng. Jct., Columbus250 oN / 20 km from burn 105 oN / 25 km from burn Communication

15. Bungalow Rd., Augusta 250 oN / 20 km from burn Ft. Benng. Jct., Columbus105 oN / 25 km from burn Fine PM Mass and Compositionat Urban Receptor Sites in April 2004 • 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. Lee et al., Environ. Sci. Technol., 2005 Communication

16. Bungalow Rd., Augusta 250 oN / 20 km from burn Ft. Benng. Jct., Columbus105 oN / 25 km from burn Source Apportionment for Organic Carbonat Urban Receptor Sites in April 2004 rain • Motor vehicles and prescribed burning are major contributors to ambient [OC]. • Prescribed burning emissions contribute esp. during and immediately after the burns. • Large unexplained fraction during (+after) regional rain events, possibly due to SOA but needs further investigation! Lee et al., Environ. Sci. Technol., 2005 Communication

17. Importance of direct (primary) and indirect (secondary) emissions to air quality and human exposure? O3 SOA Others CO CO2 VOCs NOx PM Toxics Communication

18. Opportunities & Needs for Future Work (1) Emissions • More emission characterizations needed to differentiate specific land use types and fuel types (incl. soils) across GA and the entire SE. • More accurate fuel consumption needed for improved emission factors. Transport & Transformation • Tracking of plume for assessment of chemical reactivity and trans-formation potential of aerosol species for models validation. • Determine aerosol infiltration by size/specie into commercial and residential environments to aid in human exposure assessments. Communication

19. Opportunities & Needs for Future Work (2) Modeling Different Scales • Evaluate past PM2.5 data linked to burn forecast products to improve existing modeling tools and local to sub-regional Smoke Management Plans. • Ecological response to PB needs to be understood geographically resolved in order to develop optimum burn strategies. • Develop clear guidelines of receptor model applications for air quality management that are valid for different States across SE-US. • Investigate impacts for larger temporal and spatial scales: Strategies under changing climate, ecology, land use, energy demand, human health, recreation, etc.? Courtesy of Y. Wang, EAS, GIT, 2006. Communication

20. For questions email kb@rti.org or call (919) 485-2660. Opportunities & Needs for Future Work (3) Human Exposure • Investigate health implications from personal exposures to primary emissions at the SOURCE: True exposure? Biomarkers? NIOSH? • Assessing health risks from community exposure DOWNWIND: True exposure? Biomarkers? • RTI specialty area: CAT experts support all EPA-NERL contracted personal exposure studies! • RTI-CAT developed methodology and instrumentation that has contributed to the success of major research programs. Thank You!! Communication

21. Supplemental Information Communication

22. Fort Benning F4-W PB (381 acr) from ca. 4 miles away Communication

23. Local Source - Receptor Relationship (Fort Benning) (OLC) Objective: establish relationships between observed and forecasted parameters combining PCA with linear regression analysis. Goals: i) improve fire forecasting capabilities of GFC, ii) estimate influence of fires at Fort Benning on monitored PM2.5 levels. Method: assume 12 independent variables (6 observed, 6 forecast) and one dependent variable (olc_PM) as daily input spanning Aug-01 to Sep-03 (n=689). Communication

24. Health Dept. If outlier removed, slope = 0.87 +-0.03 Crime Lab. Oxbow Meadows Environmental Learning Center PM2.5 (mg m-3) Comparison 4-Year Period vs. Oct-Nov 2001 OLC reads systematically high: larger distance of EPD’s monitors to installation beneficial in long- & short-term. Reverse conditions occur only sporadically: reasons need to be investigated further (e.g. transport from west?). Communication

25. Ambient Conditions at EPD Receptor Sites in April 2004Bungalow Rd., Augusta Ft. Benng. Jct., Columbus Communication

26. CMB Sensitivity to Different PB Source ProfilesComparison with Hays et al., while all other source profiles remained same! Linear least-square regression results (± std.err., 95% confid.) of our study (y) vs. Hays et al. (x) • Applying the PB source profile determined from this “real world” study yields 27 % lower [OC] contribution compared to laboratory simulations of similar fuel type. • But less EC apportioned to our PB source, leads to 20 % higher diesel contribution. Communication

27. CMB Results: SCEComparison with Hays et al., while all other source profiles remained same! Veg Det: Rogge et al., ES&T 27, 2700-11, 1993 Rd Dust: Zheng et al., ES&T 36, 2361-71, 2002 Meat Ck: Schauer et al., ES&T 33, 1566-77, 1999 Diesel: Schauer et al., ES&T 33, 1578-87, 1999 Gas Veh: Schauer et al., ES&T 36, 1169-80, 2002 • Rx Burn lab profile [Hays et al., 2002] tends to over-apportion more than in situ profile. Communication

28. CMB Model Performance ChecksComparison with Hays et al., while all other source profiles remained same! Calc/Meas Mass Ratio • The in situ profile of this study explains measured mass more closely. • Other performance parameters (CHI2, R2, %-mass) are also improved. Communication

29. Effect of Fireplace Profile [Fine et al., 2002] on CMB ResultsComparison with Hays et al., while all other source profiles remained same! • OC mass remains largely under-apportioned by the SCE even on days/nights with direct plume impact (e.g. 4/16 and 4/29). • Fireplace SCE appears only in max. 3 samples (4/17, 18, 30) statistically > 0. Communication

30. Effect of Fireplace Profile [Fine et al., 2002] on CMB ResultsComparison with Hays et al., while all other source profiles remained same! • Main performance parameters are generally worse when fireplace markers are incl. • Removing Retene (a SV-PAH) and Dehydroabietic acid (marker for other sources incl. tire wear) effectively tracks all biomass aerosol with Levoglucosan. Communication

31. Major Findings • Climatological effect of precipitation-rich years beneficial for PM2.5 attainment. • Local impacts from high PB and wild fire intensities cause violation of 24h and also annual NAAQS for [PM2.5]. • Annual PM2.5 NAAQS is sensitive to i) SOA formed under regional stagnation in summer; ii) Primary PM2.5 from local sources at night in winter; iii) regional transport within air sheds. • PCA and regression analysis yields strong correlations between temperatures, wind speeds, forecasted precipitation and fire occurrence, with [PM2.5] at OLC. • Substantial aromatic & biogenic HC emissions have implications for O3 and PM2.5 modeling. • Emission Factors (EF) higher at smoldering than flaming; even more as C content increases. • Indications for significant emissions of gas- and particle-phase species from soil organisms (e.g. NH3, cholesterol) not represented in lab simulations. • PB emissions contribute esp. during and immediately after the burns up to 85 % of total OC. Communication

32. CMB Specific Findings • Application of in situ PB emissions profile yields lower contributions to [OC] than laboratory generated profile at the expense of a higher diesel contribution. • Removing fireplace profile and fitting species eliminates collinearity effects and improves CMB model performance significantly. • Removal of fireplace source and tracers was justified by i) few SCE > 0, ii) warm late spring season with likely little occurrence, and iii) uncertain tracers. • Chosen n-Alkanes do not uniquely track vegetative detritus, so that if Si was missing, some of the VD-apportioned OC may actually be from soil. • Oleic acid worked better as meat tracer than cholesterol here, due to significant levels detected in the in situ PB profile. Communication