Temporal and Spatial Variations

of PM2.5 Mass in Georgia

Xiaolu Zhang

EAS 6410 Spring 2007

Introduction

• PM2.5 : particulate matter with an aerodynamic diameter ≤ 2.5 µm ( fine particle )

• Formation: primary and secondary

Precursors include SO2, NOx, NH3, VOC

• Adverse effects: public health, poor visibility…

Organic Carbon

41%

Elemental Carbon

6%

Nitrate6%

Sulfate31%

Other2%Ammonium

Ion10%

Crustal4%

PM 2.5 composition - Atlanta

NAAQ Standards for PM2.5

• NAAQS: National Ambient Air Quality Standard • Annual PM2.5 standard: the annual arithmetic mean

concentration ≤ 15.0 µg/m3

• 24-hour PM2.5 standard: the 98th percentile 24-hour

concentration ≤ 65 µg/m3

• Non-attainment areas in Georgia ( 2004 )

PM2.5 Nonattainment Areas

WALKER

CHATTOOGA

FLOYD

POLK

GORDON

WHITFIELD

MURRAY

GILMER

PICKENS

CRISP

WILKES

T ALIAFERRO

W ARREN

JEFFERSON

GLASCOCK

BURKE

COLUMBIA

LINCOLN

McDU

LAURENS

DODGE

PULASKI

WILCOX

TELFAIR

WHEELER

HOUSTON

PEACH

MONROE

JASPER

JONES

PUTNAM

HANCOCK

TWIGGS

BALDWINW ASHINGTON

JOHNSONWILKINSON

BLECKLEY

IRWIN COFFEE

ATKINSON

CLINCH

ECHOLS

LOWNDES

BROOKS

COLQUITT

COOK

LANIER

TIFT

TURNER

BERRIEN

BEN HILL

W ARE

CHARLTON

CAMDEN

GLYNN

McINTOSH

W AYNE

BRANTLEY

PIERCE

BACON

EFFINGHAM

CHA THAM

BUTTS

LONG

LIBERTY

BRYAN

BULLOCH

SCREVEN

JENKINS

EMANUEL

CANDLER

EVANS

TATTNAL

APPLING

JEFFDAVIS

TOOMBS

MONT-GOMERY

TREUTLEN

FANNIN

UNION

TOWNS

PAULDING

HARALSON

HEARD

COWETA

DOUGLAS

FAYETTE

CHEROKEE

HENR Y

ROCK-DALE

WORTH

LEETERRELL

RANDOLPH

QUITMAN

CLAY

CALHOUNDOUGHERTY

EARLYBAKER

MITCHELLMILLER

SEMINOLE

DECA TUR GRADY

THOMAS

SUMTER

DOOLY

STEWART

WEBSTER

CHA TTA-HOOCHEE

MARION

SCHLEY

TAYLOR

MACON

CRA WFORD

UPSON

TALBOT

TROUP

MERIWETHER

PIKE LAMAR

JACKSON

FORSYTH

LUMPKIN

RABUN

STEPHENS

BANKS FRANKLIN

HART

ELBERT

OGLETHORPE

CLARKE

MORGAN

GREENE

WHITE

HABERSHAM

HALL

WALTON

NEWTON

SPALDING

BARTOW

CARROLL

RICHMOND

BARROW

DAWSON

BIBB

AtlantaChattanoogaFloyd CountyMacon

BIBB

RICHMOND

CLARKE

MUSCOGEE

HARRIS

OCONEE

MADISON

DADECA TOOSA

COBB

FULTONCLAYTON

GWINNETT

DEKALB

Data AcquisitionGeorgia’s Ambient Monitoring Program (AMP)

ATHENS

CONFDAVE

GWINNETT

MCDONOUGH

NEWNAN

YORKVILL

WALTON

SDEKALB

AUGUSTA

COLUMBUS

MACON

SAVLA

Urban

Urban

Urban

Urban

Rural

Rural

Urban

Urban

Rural

Urban

Urban

Urban

Sampling Method

• Tapered Element Oscillating Microbalance (TEOM)

– On-line measurement

– Directly measures PM mass by measuring the

changing weight of a filter as it accumulates

particles

– Is sensitive to humidity and temperature

– Detection limit ~ 1.5 µg/m3

0

10

20

30

40

50

04/06/07 04/07/07 04/08/07 04/09/07 04/10/07 04/11/07 04/12/07 04/13/07 04/14/07 04/15/07 04/16/07

EST

PM

2.5

Mass (

µm

m-3

)

(Rain)(Rain)

70

60

50

40

30

20

10

0

Fin

e A

ero

sol M

ass,

µg m

-3

8/10/99 8/11/99 8/12/99

Eastern Standard Time

PM2.5

Sulfate

OM

EC

24h VS 1h avg. Metro Atlanta

• PM spikes often driven by sulfate

precipitation – negative impact

• PM2.5 mass strongly influenced by

Atlanta vs Rural

Yorkville, GA~80 km west of Confed. Ave.

Atlanta vs Rural

0

5

10

15

20

25

30

35

40

0 4 8 12 16 20 24

EST

PM

2.5

Mass (

ug

/m3)

0

3

6

9

12

15

18

0 4 8 12 16 20 24

EST

PM

2.5

Mass (

ug

/m3)

04/11/07

Most polluted day

04/07/07

Cleanest day

Confed. Ave

Yorkville

Spatial Variation In Georgia

0

5

10

15

20

25

30

4/6/07 4/7/07 4/8/07 4/9/07 4/10/07 4/11/07 4/12/07 4/13/07 4/14/07

EST

PM

2.5

Mas

s (u

g/m

3) Athens

Urban ATL

Rural ATL

Augusta

Columbus

Macon

Savannah

• Highest concentration: Urban Atlanta, Savannah

• Lowest concentration: Rural Atlanta, Athens

• Similar pattern of curves

Correlations with Metro Atlanta Concentration

Site R2

ATHENS 0.8349

GWINNETT 0.8874

MCDONOUGH 0.9756

NEWNAN 0.9413

SDEKALB 0.9236

WALTON 0.801

YORKVILL 0.9423

AUGUSTA 0.9074

COLUMBUS 0.8729

MACON 0.7346

SAVLA 0.1379

High correlations with metro Atlanta PM2.5 are found for most sites. ( R2 > 0.7 )

Similar weather condition is a possible reason of high correlations

Exception: Savannah

Conclusion

• Precipitation has a strong negative impact on PM2.5 mass concentration.

• In urban site PM2.5 mass is significantly higher than in rural site.

• Urban Atlanta and Savannah have the highest PM2.5 mass concentration while rural Atlanta and Athens have the lowest.

• Most cities have high correlations with Atlanta in PM2.5 mass except for Savannah.

Thanks !