Transcript Air Quality Impacts from Prescribed Burning

Air Quality Impacts from
Prescribed Burning
Karsten Baumann, PhD.
Polly Gustafson
Clean
Air
Act
Endangered
Species
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 designated the 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 ?
CO
CO2
O3, SOA
VOCs
Toxics
PM
NOx
Organic carbon (OC) is a dominant species of particulate
emission.
Emission Factors (EF) higher at smoldering than flaming;
even more as C content increases.
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
16
6
40 15 : OC/EC ratio
Source Apportionment at Receptor
Sites
Comparison of PB profile with Hays et al., while all other source profiles remained same!
8
Hays et al.
Others
This study
Vegetative Detritus
Fireplace
Ft.G.
burn 2
3
OC (mg/m )
6
Ft.B.
burn 1
Ft.B.
burn 2
Prescr Burning
Road Dust
Ft.G.
burn 1
4
Meat Cooking
Diesel Vehicles
Gasoline Vehicles
2
0
4/13
4/15
4/16
4/17
4/18
4/27
4/28
4/29
4/29
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 %)
4/30
4/30
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)?
Questions?