Operating Experience with a Near-Real-Time Ambient Airborne Metals Instrument System (Cooper Environmental Systems Xact 620)

Missouri Department of Natural Resources, Air Pollution Control Program and Environmental Services ProgramWashington University, St. LouisU. S. EPA

National Ambient Air Monitoring Conference, Nashville, Tennessee

November 2-5, 2009

Introduction

●

The St. Louis Community Air Project (CAP) and the Blair St. National Air Toxics Trends Station (NATTS) have measured elevated concentrations of airborne arsenic in St. Louis.

●

Missouri DNR and Washington University obtained a Community-Scale Air Toxics grant from EPA to better determine sources of arsenic and other species in St. Louis.

●

A Cooper Xact 620 was purchased on this grant and operated at multiple sites.

Project Plan

• Phase I. Spatially and Temporally Enhanced 24-hour Integrated Measurements– 1-in-3 day PM10 sampling and metals analysis by

ICPMS at 4 sites in the St. Louis area for 1 year (MDL~0.02-0.03 ng/m3, 24-hr samples)

• Phase II. High Time Resolution Measurements– Time-resolved near-real-time analysis at six sites in

the St. Louis area for 1 month at each site (MDL<0.1 ng/m3, possibly as low as 0.01 ng/m3, 2- hr samples)

• Data Analysis and Reporting– Source apportionment, source identification, model

comparisons

Cooper Environmental Services Xact 620 Ambient Air Toxic Metals Monitor

PM10 size-selective inlet

Temperature controlled cabinet

Heater

Sampling & Analysis Module

Operator interface/control panel

Flow control module

Xact Sampling and Analysis

XX--Ray TubeRay Tube

Filter TapeFilter Tape

Aerosol DepositAerosol Deposit

Chemistry ZoneChemistry Zone

Sample FlowSample Flow

Analysis AreaAnalysis Area

Filter TapeFilter Tape

Previous sample is analyzed while current sample is collected

Xact Tape Deposits

Deposit Area 0.747 cm2

Phase II Xact Monitoring Sites

MISSOURI

ILLINOIS

Xact vs. LowVol PM10 FRM / XRF

18-hour integrated filter with offline XRF, ng/m3

-2 0 2 4 6 8

18-h

our a

vera

ge X

act,

ng/m

3

-2

0

2

4

6

8

Selenium

18-hour integrated filter with offline XRF, ng/m3

-2 0 2 4 6 8

18-h

our a

vera

ge X

act,

ng/m

3

-2

0

2

4

6

8

Arsenic

Se and As: pushing the detection limit of the lab-based XRF.need to compare the Xact to ICP-MS (next slide)…

Selenium: Xact vs. Filter-Based Measurements

PM10 selenium, 24-hour integrated filter, ng/m3

0.0 0.5 1.0 1.5 2.0

PM

10 s

elen

ium

, 24-

hour

ave

rage

Xac

t, ng

/m3

0.0

0.5

1.0

1.5

2.0

BlairArnold

Xact

= (1.15 ±

0.10)×filter + (-0.040 ±

0.089)

Xact vs. HiVol filter / lab ICP-MS

18-hour integrated filter with offline XRF, ng/m3

-2 0 2 4 6 8

18-h

our a

vera

ge X

act,

ng/m

3

-2

0

2

4

6

8

Xact vs. LowVol filter / lab XRF

Se: favorable comparison between Xact and PM10 HiVol samples with analysis by ICP-MS

Arsenic – Methods Comparisons

MDNR/WUSTL analysis, ng/m3

-2 0 2 4 6 8

NA

TTS

/ E

RG

ana

lysi

s, n

g/m

3

-2

0

2

4

6

8

Collocated HiVol SamplersBlair site, 4th Quarter 2008

24-hour integrated HiVol PM10, ng/m3

-2 0 2 4 6 8

24-h

our a

vera

ge X

act,

ng/m

3

-2

0

2

4

6

8

Xact vs. WUSTL HiVolDec 2008 / Jan 2009

As: favorable comparison between Xact and PM10 HiVol samples with analysis by ICP-MS.

Xact vs. LowVol PM10 FRM / XRF

18-hour integrated filter with offline XRF, ng/m3

0 20 40 60 80 100

18-h

our a

vera

ge X

act,

ng/m

3

0

20

40

60

80

100

Titanium

Xact

= (1.05 ±

0.04)×filter + (-2.2 ±

2.8)

18-hour integrated filter with offline XRF, ng/m3

0 50 100 150 200 250 300 350

18-h

our a

vera

ge X

act,

ng/m

3

0

50

100

150

200

250

300

350

Xact

= (0.84 ±

0.21)×filter + (28 ±

25)

Potassium

Xac t vs  F RM Iron

y  = 1.1904x  ‐ 0.8478

R 2 = 0.9928

050

100150200250300350400450

0 100 200 300 400

F RM Iron  (ng /m3)

Xac

t Iron (ng/m

3

X ac t vs  F RM Zinc

y  = 1.0626x  + 5.0407

R 2 = 0.9989

0

200

400

600

800

1,000

0 200 400 600 800 1,000

F RM Zinc  (ng /m3)

Xac

t Zinc (ng/m

3

Herculaneum, MO

Xact vs. LowVol PM10 FRM / XRF

18-hour integrated filter with offline XRF, ng/m3

0 5 10 15 20 25 30

18-h

our a

vera

ge X

act,

ng/m

3

0

5

10

15

20

25

30

Manganese

Xact

= (1.46 ±

0.18)×filter + (0.7 ±

1.6)

18-hour integrated filter with offline XRF, ng/m3

-5 0 5 10 15 20 25 30

18-h

our a

vera

ge X

act,

ng/m

3

-5

0

5

10

15

20

25

30

Lead

Xact

= (1.02 ±

0.10)×filter + (-0.1 ±

1.8)

Mn: biased but highly correlated

Herculaneum

Xact Lead (ng/m3)

y = 0.9967x + 7.4451R2 = 0.9979

02000400060008000

10000120001400016000

0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000

CES

MO

n = 202

Minus High Concentration Data Point

FRM Comparison Daily Av. Conc.

Herculaneum MO

Xac t vs  F RM L ead

y  = 1.0651x  + 15.451

R 2 = 0.9976

0

500

1,000

1,500

2,000

2,500

3,000

0 500 1000 1500 2000 2500 3000

F RM L ead  (ng /m3)

Xac

t Lea

d (ng/m

3)Herculaneum, MO Lead

NAAQS Analytical Comparison Region

y = 1.1783x - 1.2202R2 = 0.9946

0

50

100

150

200

250

300

350

400

0 50 100 150 200 250 300 350

FRM v. Xact Lead Comparison

FRM (ng/m3)

Xact

(ng/

m3)

PM10 Lead by Xact (2-hour resolution)

Dashed line is bearing of Doe Run – Herculaneum lead smelter

PM10 lead, ng/m3

0 50 100 150 200 250 300

win

d di

rect

ion,

o N

0

45

90

135

180

225

270

315

360

BLAIR ARNOLD

PM10 lead, ng/m3

0 50 100 150 200 250 300

win

d di

rect

ion,

o N

0

45

90

135

180

225

270

315

360

Hourly PM10 Lead, Herculaneum Main Street Site, 8/8/09 – 10/10/09Excludes hours with wind speeds less than 0.5 mph

Excludes one value > 15,000 ng/m3

Monitoring Site

Doe Run

Herculaneum Airborne Lead ConcentrationAugust and September 2009

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

8/1/20

098/3

/2009

8/5/20

098/7

/2009

8/9/20

098/1

1/200

98/1

3/200

98/1

5/200

98/1

7/200

98/1

9/200

98/2

1/200

98/2

3/200

98/2

5/200

98/2

7/200

98/2

9/200

98/3

1/200

99/2

/2009

9/4/20

099/6

/2009

9/8/20

099/1

0/200

99/1

2/200

99/1

4/200

99/1

6/200

99/1

8/200

99/2

0/200

99/2

2/200

99/2

4/200

99/2

6/200

99/2

8/200

99/3

0/200

9ug

/m3

TSP Hi-Vol ug/3m Xact ug/3m

Every Day Sampling

Herculaneum Airborne Lead ConcentrationAugust and September 2009

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

8/1/20

098/3

/2009

8/5/20

098/7

/2009

8/9/20

098/1

1/200

98/1

3/200

98/1

5/200

98/1

7/200

98/1

9/200

98/2

1/200

98/2

3/200

98/2

5/200

98/2

7/200

98/2

9/200

98/3

1/200

99/2

/2009

9/4/20

099/6

/2009

9/8/20

099/1

0/200

99/1

2/200

99/1

4/200

99/1

6/200

99/1

8/200

99/2

0/200

99/2

2/200

99/2

4/200

99/2

6/200

99/2

8/200

99/3

0/200

9ug

/m3

DR City Hall ESP Main St. ESP Main St. Co Xact

Every 3 Day Sampling

Herculaneum Airborne Lead ConcentrationAugust and September 2009

y = 0.5902x + 0.0291R2 = 0.8649

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

TSP Hi-Vol, ug/m3

Xac

t, ug

/m3 1:1

Herculaneum Airborne Lead ConcentrationAugust and September 2009

y = 0.771x - 0.0386R2 = 0.982

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 0.5 1 1.5 2 2.5 3 3.5

TSP Hi-Vol, ug/m3 (2 high days not included)

Xac

t, ug

/m3 1:1

Conclusions

• Maintenance and operation of the Xact is comparable to that of other air monitoring instruments. The Xact has operated reliably following initial problems addressed by software and firmware upgrades.

• Xact airborne metallic species results compare well with both low volume and high volume filter sample analysis results.

• Xact results demonstrate the utility of time- dependent measurement for source attribution.

Acknowledgements• Missouri Department of Natural Resources

• Jim Brunnert, Jerry Downs, Celeste Koon, Dustin Kuebler, Robert Nilges, Terry Rowles, Will Wetherell

• Washington University• Stephen Feinberg, Jay Turner, Varun Yadav

• Cooper Environmental Services• John Cooper, Krag Petterson

• City of St. Louis Air Pollution Control• Joe Gallagher,Don Simpson, Tom Wiese

• U.S. EPA / Office of Air Quality Planning and Standards• Mike Jones

• U.S. EPA / Region VII• Gwen Yoshimura

• U.S. EPA / Office of Research and Development• Teri Conner, Gary Norris, Bob Willis

Online Current Data

• http://www.dnr.mo.gov/env/esp/aqm/allguide.htm(Click on “Current Air Pollution Data Report” at mid-page, scroll down to St. Louis Metals Data)