1. Increased PM2.5 at Columbus due to local source, 2001
Measurements of Prescribed Burning Emissions at Columbus, Georgia Sangil Lee1, Karsten Baumann2, Venus Dookwah2, Mei Zheng2 1School of Civil and Environmental Engineering, 2School of Earth and Atmospheric Sciences Georgia Institute of Technology, Atlanta, Georgia
 Objective
Guided by the Endangered Species Act (ESA), the DOI through the Fish and Wildlife Service mandates that most army and air force bases in the
South-Eastern US use prescribed burning to maintain the health of its native long leaf pine forest and thus protecting the habitat of the endangered
red-cockaded woodpecker. In recognition of the conflicting requirements between the ESA and the Clean Air Act (CAA) statutes, the “Study of Air Quality
Impacts Resulting from Prescribed Burning on Military Facilities” was initiated and sponsored by the DOA/CERL in support of the DOD Pollution prevention
Partnership.
 Prescribed Burning
 Develops, maintains, and enhances wildlife habitat.
 Protects endangered plants and animals.
 Preserves and protects cultural resources, scenic vistas, and wilderness.
 Minimizes potentials of catastrophic wildfires that could result from heavy accumulations of vegetative fuels.
 Air Quality Issues associated with Prescribed Burning
Emissions from prescribed burning are important primary sources of gases and particulate matter (PM) to the atmosphere.
 fine particles are main contributor to smoke, impairing visibility.
 particles less than 2.5mm are released, which are respirable.
 organic compounds make a large portion of particles, which might have potential of adverse health effects.
Diurnal Patterns of PM2.5 and Ozone in Metropolitan areas of Georgia, 2000~2002
Increased PM2.5 at Columbus due to local source, 2001
Diurnal patterns of ozone at several different sites show that these metro areas have similar daily trends of ozone in summer and winter time, respectively, during the past three years. Fine PM concentrations show similar tendencies except in winter time at Columbus. The increase in particulate matter from midnight to morning time indicates that there is a local source for this increase.
Fall line Air Quality (FAQS) Sites ( Augusta (Aug), Columbus (Col), Macon (Mac). Griffin (Grif), Tifton (Tift)
Like diurnal patterns, there is a regionally similar trend in particulate matter from late October to early December, except for several days, which have sudden increase in particulate matter at the Columbus site. This clearly shows that there is a local source, which is suspected as biomass burning (prescribed burning and wild fires). More calm condition during high PM2.5 episodes might account for accumulation of particulate emissions from local biomass burning.
Measurement site (Oxbow Learning Center) and Fort Benning Military Facilities (Prescribed Burning Site)
Columbus, GA
Time Series Plot of Measured Gases and Particulate Matter
January
February
March
April
May
937 acres
1256 acres
3770 acres
4067 acres
504 acres
251 acres
Background Measurement
without Prescribed burning
Low pressure system with shower and T-storm from
3rd to 4th. Very cold air moved into the measurement site
at early morning of the burn day
Highest PM2.5 event associated
with relatively calm conditions on 25th.
The decrease in temperature (T) combined with
decrease in PAR and increase in wind speed
leads to decreasingO3 maxima and [PM2.5] levels.
Relatively low wind speeds all week
Build-up in PM2.5 and O3 maxima
after record rainfalls earlier in May;
strong daytime winds
Average Diurnal Cycles
of Major Meteorological Parameters and Air Pollutant Concentrations for March
Particle Compositions for each Prescribed Burning event
Increasing fractions of Unidentified Mass (grey) with time progressing into warmer season, indicates likely larger OOE (turquoise) fraction, reflecting an organic mass to organic carbon ratio (OM/OC) increasingly larger than 1.4 likely due to higher oxygenated PM.
Organic Compounds identified by GC/MS
Non-burn week
Burn week
Non- burn week
Burn week
0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
2/2/03 0:00
2/5/03 12:00
2/5/03 17:00
2/5/03 22:00
2/6/03 3:00
2/6/03 8:00
Start Time [EST]
Concentration, ng m -3
Alkanedioic acids
Alkenoic acids
n-alkanoic acids
Branched alkanes
Levoglucosan
Other compounds
Aromatic
carboxylic acids
Resin scids
PAHs
Steranes
Hopanes
n-Alkanes
Acknowledgement
This work was sponsored by the Department of the Army/ U.S. Army Construction Engineering Research Laboratories (CERL) via subcontract with the University of South-Carolina (USC), Grant No. DACA , in support of the DOD Pollution Prevention Partnership. The authors gratefully acknowledge the collaboration and field support received by Jill Whiting, Jim Trostle, and Becky Champion (CSU-OLC), Jack Greenlee, Hugh Westbury, Polly Gustafson, and John Brent (Ft. Benning), Frank Burch and Steven Davis (Columbus Water Works), Allen Braswell and Stephen Willard (Ft. Gordon), Wes Younger and Michael Chang (GIT-EAS).
Measurements of particle-phase organic compounds (POC) have been made by a High Volume Sampler with pre-baked quartz filters.
Sampled quartz filters were extracted by organic solvent and then analyzed by Gas Chromatography/Mass Spectrometry (GC/MS).
Total 105 POCs are identified: n-alkanes (20), hopanes (10), steranes (4), polycyclic aromatic hydrocarbons (19),
resin acids (9), aromatic carboxylic acids (3), branched alkanes (3), n-alkanoic acids (17), alkenoic acids (3), alkanedioic acids (19).
Cellulose, which provides structural strength to plants, constitutes % dry weight of wood. Thermal decomposition of cellulose produces mainly
levoglucosan, a good biomass tracer, during wood combustion at T > 300 oC. Another biomass burning marker for conifers containing resin is resin acid.
Samples for the February event have been analyzed so far. Levoglucosan is dominant among organic compounds identified by GC/MS.
Two biomass tracers have very similar trend of concentrations. Their concentrations (in blue) 5 hours after burning is a factor of 2 to 5 higher than those
of background and right after burning, respectively. This increase is associated with relatively calm conditions compared to right after the burn.
Larger differences between the daily minimum and maximum air T and RH were observed on two burn weeks,
10-16 and of March, indicating overall less cloud coverage and generally drier conditions. An overall
increasing warming trend leads to more intense atmospheric photochemical activity and higher O3 maxima.
The two burn weeks were also characterized by elevated nighttime PM2.5, CO and NOy concentrations. Continued
emissions from smoldering fuel of the prescribed burnings might account for this nighttime increase, since the relatively
cold plumes (compared to daytime flaming condition) are being mixed into the shallow nocturnal boundary layer.