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Air Quality Impacts from Prescribed Burning. Karsten Baumann, PhD. Polly Gustafson. Endangered Species Act. Clean Air Act.
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Air Quality Impacts from Prescribed Burning Karsten Baumann, PhD. Polly Gustafson
Endangered Species Act Clean Air Act Military Installations in SE-US occupy endangered species habitat while maintaining ecosystems with prescribed burning activities, therefore increasing risk of NAAQS violations.
Background • Other agencies such as USEPA, USFWS, and GFC agree that prescribed burning is the best and most cost efficient method for maintaining habitat. • This study started with FLAQS which was to look at ozone in three cities. • Dodged the bullet on ozone, due to weather. • PM 2.5 followed the ozone pattern • Needed to get ahead of the curve on PM 2.5 • In the mean time, US EPA designatedthe Russell County-Muscogee Air shed non-attainment for PM 2.5. • In 2005, ADEM and GA EPD petitioned US EPA to use the figures from the spatial averaging effort. • However, numbers have to remain “GOOD” for 2005 in order to stay in attainment.
The Study • Forest Fires (wildfires & prescribed fires) are a significant source for primary PM2.5 in GA and SE-US. • PM emissions have not been well characterized, esp. particulate organic compounds (POC) in PM2.5 and their impact on air quality. • Developed an emission profile for this new PB source and estimate its contribution to ambient PM2.5 observed at the State’s regulatory monitoring sites. • Prescribed burning is indicated as primary land management tool for: • the benefit of the forest ecosystem • endangered species • and in the case of the U.S. military, DOD’s mission.
Importance of direct (primary) vs. indirect (secondary) emissions ? O3, SOA CO CO2 VOCs NOx Toxics PM Organic carbon (OC) is a dominant species of particulate emission. Emission Factors (EF) higher at smoldering than flaming; even more as C content increases.
16 6 40 15 : OC/EC ratio Comparisons With Other Studies Dr. B characterized particulate emissions from a brief pilot study in April 2004 and compared them with previous studies. Findings: • Similar identified organic mass concentrations and fractions • Different OC/EC ratios, but similar value from this study & Hays
Ft.G. burn 2 Ft.B. burn 1 Ft.B. burn 2 Ft.G. burn 1 Source Apportionment at Receptor Sites Comparison of PB profile with Hays et al., while all other source profiles remained same! PB contribution to measured ambient [OC] Hays et al. vs. This study max 1.52 mg m-3 (20 %) max 1.76 mg m-3 (28 %)
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. • Emission Factors (EF) higher at smoldering than flaming; even more as C content increases. • Application of in situ PB emissions profile yields 1.3 times higher contributions to ambient [OC] than laboratory generated emissions profiles
Recommendations • More emission characterizations needed to differentiate specific land use types and fuel types across GA and the SE. • Size and specie resolved emissions necessary to better understand mechanisms of primary and secondary PM formations. • Tracking of plume within first 2-3 hours would allow assessment of chemical reactivity and (trans-) formation potential of aerosol species. • Impacts on larger temporal and spatial scales (climate, haze, region)?