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AIR TOXICS IN ALLEGHENY COUNTY:SOURCES, AIRBORNE CONCENTRATIONS, AND HUMAN EXPOSURE

CMU: Jennifer Logue, Kara Huff-Hartz, Andrew Lambe, Allen Robinson, Neil Donahue, Mitch Small, Cliff DavidsonACHD: Roger Westman, Darrel Stern, Jason MaranchePitt: Bernie Goldstein

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Description of the Problem

Purpose: Characterize air toxics concentrations, sources, and risks in Allegheny CountyRationale: Large uncertainties still exist regarding sources, exposure, and health risks mostly due to a lack of dataContext: Time resolution and consistency of these measurements allow for more in-depth analysis than has previously been possible

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Project Objectives

Ambient measurementsAmbient measurementsBaseline Baseline (ACHD)(ACHD)

Intensives Intensives (CMU)(CMU)

Estimate health risks Estimate health risks (CMU, Pitt)(CMU, Pitt)

Determine source contributions Determine source contributions (CMU)(CMU)

Evaluate relative risks Evaluate relative risks (CMU)(CMU)

Local vs. regional sources Local vs. regional sources Pittsburgh vs. other citiesPittsburgh vs. other cities

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Monitoring Sites

Industrial Sites

Regional Background Site

Downtown

Mobile Dominated Site

Stowe

Avalon

South Fayette

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Design and Implementation of Project

Two types of measurementsBaseline

4-sites24hr average concentrationsMeasured 1:6 for a yearCanisters (TO-15 standard)Cartridges (TO-11a standard)

Intensives3-sitesHourly measurements for 1 to 2 monthsGas and particle phase measurements

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Automated Field InstrumentGas Chromatograph Mass Spectrometer/ Flame Ionization Detector (GCMS/FID)

(Millet JGR, 2005)

1 hour resolution

70+ compounds

Low detection limit(<.2μg/m3)

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Compounds MeasuredToluene Chrysene Chloromethane2-Butanone (MEK) Benzo[ a]anthracene QuinolineMethyl alcohol Fluorene Benzo[k]fluorantheneStyrene Tetrachloroethene 1,1,2-TrichloroethaneBenzene Acenaphthene Chlorobenzene4-Methyl-2-pentanone (MIBK) Anthracene cyclohexaneNaphthalene o-Xylene 1-PropanolEthylbenzene Chloroform ChloroethaneCarbon disulfide p-Xylene AcrylonitrileMethyl-t-butyl either(mtbe) Vinyl chloride 1,2-Dichloroethane1,2,4-Trimethylbenzene Heptane 1,1-DichloroethaneIsopropylbenzene Ethyl acetate 1,1,1-TrichloroethaneEthylene oxide Trichloroethene Benzo[ b]fluoranthenePhenanthrene 1,1,2,2-Tetrachloroethane BromochloromethaneMethylene chloride Vinyl acetate PyridineMethyl methacrylate 1,4-Dioxane n-PropylbenzeneBromomethane Acrolein (Propenal) 1,2-DichlorobenzeneFluoranthene Acenaphthylene BromoformPyrene Benzyl chloridem-Xylene 1,4-Dichlorobenzene

*Simultaneous measurements of local meteorology and criteria pollutants

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Measurement Inter-comparison

Toluene

Slope= 1.6

0

2

4

6

8

10

12

0 2 4 6 8 10 12

Hourly Measurments (microg/m3)

Can

iste

r Mea

sure

men

ts

(mic

rog/

m3)

Benzene

Slope=1.394

0

1

2

3

4

5

6

0 1 2 3 4 5 6

Hourly Measurments (microg/m3)

Can

iste

r Mea

sure

men

ts

(mic

rog/

m3)

Averaged Hourly Averaged Hourly

Slope= 1.6Slope= 1.4

Can

iste

r

Can

iste

r

Toluene Benzene

9

0

1

2

3

4

5

6

Styren

e

Tetrac

hloroeth

ylene

o-Xyle

nem &

p- Xyle

ne

1,3-di

chloro

benze

ne

1,2,4-

Trimeth

ylben

zene

Ethyl Ace

tate

1-Ethyl-

4-Meth

ylben

zene

1,3-B

utadien

eEthylb

enze

ne

1,3,5-

Trimeth

ylben

zene

1,4-D

ichlor

oben

zene

Benze

ne

Rat

io w

ith R

egio

nal B

ackg

roun

d

Pittsburgh Avalon Stowe

Air toxic concentrations relative to South Fayette

4:1

2:1

10

Seasonal Variations

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High Temporal Resolution

24hr AverageHourly Concentration

12

0.0

0.3

0.5

0.8

1.0

Styrene

Toluene

Benzene

Plume Events

0.0

0.2

0.4

0.6

0.8

1.0

0

2

4

6

8

10

12

14

1 3 9 10 11 17 18 19 21 22October 2006

Con

c. ( μ

g/m

3)

benzenetoluenestyrene

Wind from Wind from Neville Island Downtown

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Benzene by Day of the Week in Avalon

Sat Sun Mon Tues Wed Thurs Fri

0

2

4

6

8

10

12C

once

ntra

tion

(mic

rogr

ams/

m3)Benzene

Benzene

Hou

rly C

once

ntra

tion

(μg/

m3)

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Average Diurnal Patterns at Avalonbenzene

1

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

02:0

04:0

06:0

08:0

010

:0012

:0014

:0016

:0018

:0020

:0022

:00

Military Time

Con

cent

ratio

n(m

icro

g/m

3)

toluene

1

1.5

2

2.5

3

3.5

4

02:0

04:0

06:0

08:0

010

:0012

:0014

:0016

:0018

:0020

:0022

:00

Military Time

Con

cent

ratio

n(m

icro

g/m

3)

cyclohexane

0

0.05

0.1

0.15

0.2

0.25

02:0

04:0

06:0

08:0

010

:0012

:0014

:0016

:0018

:0020

:0022

:00

Military Time

Con

cent

ratio

n(m

icro

g/m

3)

styrene0.8

1

1.2

1.4

1.6

1.8

02:0

04:0

06:0

08:0

010

:0012

:0014

:0016

:0018

:0020

:0022

:00

Military Time

Con

cent

ratio

n(m

icro

g/m

3)

Con

cent

ratio

ns (μ

g/m

3)

Con

cent

ratio

ns (μ

g/m

3)

Time of day Time of day6am 12pm 6pm 6am 12pm 6pm

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Estimating Lifetime Cancer Risk

BWIRfC

LADD apercentileth **,95=

SFLADDLIR *=

Lifetime Averaged Daily Dose:

Lifetime Individual Cancer Risk:

SF=Slope Factor

Linear No-Threshold Model:

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Air Toxics Cancer Risks

0.E+00 5.E-06 1.E-05 2.E-05 2.E-05

Benzene

Carbon Tetrachloride

Trichloroethene

Butadiene, 1,3-

Chloroform

Tetrachloroethene

Dichlorobenzene,1,4-

Dichloroethane,1,2-

Hexachlorobutadiene

Methylene Chloride

Bromodichloromethane

Dichloropropane,1,2-

Lifetime Cancer Risk

StoweDowntownAvalonBackground

Risk=10-6

0E00 5E-6 1E-5 1.5E-05 2E-5

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Non-Cancer Health Risks

ChronicAnnual 95th percentile canister data

Intermediate and AcuteMaximum hourly concentration at Avalon: 14 days to 1 year

RfCionConcentratHQ =

HQ=Hazard Quotient RfC = Reference Concentration

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Non-Cancer Risks

0.00 0.20 0.40 0.60 0.80 1.00

HAZARD INDEX

BUTADIENE, 1,3-

HEXACHlOROBUTADIENE

ACETONE

BENZENE

XYLENE, m-

TOLUENE

CHLOROMETHANE

BROMOMETHANE

CARBONTETRACHLORIDE

XYLENE, o-

Hazard Qoutient

StoweDowntownAvalonBackground

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Comparison of Aggregate Air Toxics Risks

0.0E+00 5.0E-05 1.0E-04 1.5E-04 2.0E-04

PAHs Risk

HAP Risk (South Fayette)

HAP Risk (Stowe)

Metals Risk

HAP Risk (Avalon)

HAP Risk (Flag Plaza)

Lifetime Cancer Risk

(Background)

(Background)

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1 2

0

5

10

15

20

25

30

35

40

Val

ues

Colu

How does Allegheny County compare to other cities?

1 2 3 4 5

0

0.5

1

1.5

2

2.5

3

3.5

Val

ues

Column Number

AvalonStoweDowntownBackground

1,3 Butadiene CCl4 Chlorform TCE Chloroethene

Con

cent

ratio

n ( μ

g/m

3)

Benzene Toluene

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Downtown Exposure: Trichloroethene

0.0

0.2

0.4

0.6

0.8

1.0

1/5/062/5/063/5/064/5/065/5/066/5/067/5/068/5/069/5/0610/5/0611/5/0612/5/06

Con

cent

ratio

n ( μ

g/m

3)

0

10

20

30

40

50

1996 1998 2000 2002 2004 2006 2008

Year

Con

cent

ratio

n (9

5% μ

g/m

3)

0.E+00

2.E-04

4.E-04

6.E-04

8.E-04

1.E-03

Life

time

Can

cer R

isk

(95t

h pe

rcen

tile)Annual Averaged

Time Series 2006

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Source Apportionment

Main issue: Associating sources and factorsEvent profilesSource profiles

GFX =PMF solves:

scores loadings

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10 20 30 40

30

210

60

240

90270

120

300

150

330

180

0

Mobile Gasoline Factor

PMF Factor

Factor Contribution vs.

Wind Direction

300

60

90

120

150180

210

240

270

330

300

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Pittsbur gh

Source Profile

Toluene Toluene

M/P Xylene

M/P Xylene

Benzene

Styrene

24

10 20 30 40 50

30

210

60

240

90270

120

300

150

330

180

0

Water Treatment Factor

PMF Factor

Factor Contribution vs.

Wind Direction

030

60

90

120

150180

210

240

270

330

300

ACSA

1

ACSA Emission Profile

Tetrachloroethylene

Toluene

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0% 20% 40% 60% 80%

benzene

styrene

toluene

MEK

methylene chloride

1,1,1_trichloroethane

acetone

o-xylene

1,2,4_trimethylbenzene Cancer Risk

Exposure

Linking Risk to Sources

Neville Factor

Benzene

Styrene

Toluene Avalon Site

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NATA Evaluation by Pollutant

0

2

4

6

8

0 2 4 6 8

Modeled Conc.(μg/m3)

Mea

sure

d C

once

ntra

tion

( μg/

m3) 1:12:1

1:2

Toluene

Benzene0.0

0.5

1.0

1.5

2.0

0 0.5 1

Modeled Conc.(μg/m3)

Mea

sure

d C

once

ntra

tion

( μg/

m3)

2:1

1:2

1:1

1-3 Butadiene

Styrene

CCl4

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NATA Evaluation by Site

0

0.5

1

1.5

2

2.5

3

1,3-Butadiene Benzene Chloroform Toluene

Mea

sure

d / M

odel

ed

0

5

10

15

20

25

Styrene TCE

0

0 . 5

1

1. 5

2

2 . 5

3

1 , 3 - B u t a d ie n e B e n z e n e C hlo r o f or m T o lue n e

Avalon Stowe Downtown Background

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NATA Evaluation: Source ApportionmentBenzene

0%

25%

50%

75%

100%

Downtown(NATA)

Avalon (NATA)

Background(NATA)

Stowe (NATA)

Avalon (PMF)

Downtown Avalon Background Stowe Avalon (PMF)

(NATA)

Background

Mobile

Point

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Application of Results

Quantifying risk

Source Apportionment

Policy and funding decisions

NATA evaluation

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Lessons Learned

Meeting all of our goals.

Design of the project was sufficient to meet goals and additional scientifically interesting work is being done using the results.

In retrospect

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Future Work

IntensivesDowntownSouth Fayette

Expand and improve PMF analysisSynergistic risk modelsNATA evaluation

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Acknowledgments

FundingClean Air FundEPA

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Questions