Transcript A New Approach for Locating and of Air Pollution Ronald C. Henry

A New Approach for Locating and
Quantifying the Impact of Local Sources
of Air Pollution
Ronald C. Henry
Civil & Environmental Engineering
University of Southern California
Acknowledgements
 This work is supported by a U. S. EPA Science to Achieve
Results (STAR) grant, Dr. Darrell Winner Project Officer
 Dr. Gary Norris, ORD, U. S. EPA
 USC Research Assistants
 Mr. Babak Pazokifard, Chien-Cheng Pan
 Data provided by
 Dr. Philip Fine, SCAQMD
 Dr. Jay Turner, Washington University
 Dr. Donna Kenske, Lake Michigan Air Directors Consortium
Importance of Local Sources to
Community Air Quality
 Local sources are often the major source of
the most dangerous forms of air pollution,
e.g. airborne black carbon
 Control of local sources is often more feasible
and cost effective control of regional sources
Difficulties of Local Source
Apportionment
 Traditional source-oriented air quality
modeling is often compromised by
inadequate
 Emission inventories
 Often incomplete or inaccurate, e.g. fugitive emissions
 Meteorological data, e.g. dispersion parameters
 Ability to explain observations
Difficulties of Receptor Modeling
 Only applies to particulate matter and VOCs
since chemical ‘fingerprints’ are needed to
apportion sources
 Problems distinguishing sources with similar
fingerprints, diesel trucks, cars, railyards
 Cannot apportion secondary particulate
matter
Hybrid Receptor Model
 Uses wind speed and direction - like a sourceoriented model
 Based on actual observations - like a receptor
model
 Local sources generally are closer than 5-10
miles and require wind and concentration
data on a time scale of less than 15 minutes
Nonparametric Trajectory Analysis
(NTA) Methodology
 Unique in using 1-minute met data and pollutant concentration
data
 Calculate minute by minute back trajectories from a monitoring
site
 Associate each point on the back trajectory with the
concentration of the pollutant when the trajectory arrives at the
site
 Use nonparametric regression to estimate the average
concentration at the monitor when air passes over each
geographical point.
1-Minute SCAQMD Data
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All sites from Jan. 2004 to September 2006
Criteria pollutants
Wind Speed and Direction
Other met data
Thanks to Dr. Philip Fine, SCAQMD
NTA Example
North Long Beach, CA Site
Long Beach Local
2-Hr Back Trajectories
NTA Long Beach 1-Minute SO2
Summer 2005
NTA Long Beach 1-Minute PM10
Winter 2005
Black Carbon / Aethalometer
Examples
 E. St. Louis Super Site - Dr. Jay Turner
 5 minute data for third quarter, 2001
 Detroit - Dr. Donna Kenski, Lake Michigan Air
Directors Consortium
 5 - minute data
 LAX - Southern California Particle Center - Dr.
John Froines
 5 minute data June, 2006
East St. Louis Super Site
Rail Yard BC Soruce
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Detroit Black Carbon
Ambassador Bridge
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
1-Minute Wind data from 6 AQMD
Sites
LAX Black Carbon Sites
June 7 - 30, 2006
LAX Black Carbon
Time Series June 2006
LAX Black Carbon
Sector Apportionment
 The highest
concentrations of BC
are associated with LAX
 Almost 60% of the
average BC may be
coming from off-shore
and other sources
Sector Apportionment
LAX SO2 June 7 - 30 2006
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
 82 percent of average
SO2 at the LAX SCAQMD
site is from the S and W
 El Segundo Marine
Terminal is a possible
source of BC and SO2
Conclusions
 1-minute observations should be routinely
archived and subjected to quality control and
assurance
 The incremental cost is small and the
potential benefits in better understanding of
local sources and improved community air
quality are very great
LAX NOX
During BC Study
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
 Highest NOX was
associated with the area
just S of the
intersection of the 405
San Diego freeway and
the 90 Marina freeway
 Lesser concentration
areas are 105 and 405,
10 and 405 intersections
Another View of LAX NOX
During BC Study
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
LAX NO/NOX Ratio
During BC Study
 High NO/NOX ratios
imply fresh emis-sions
that are associated with
LAX and off-shore
sources
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.