NATIONAL AIR TOXICS TRENDS STATIONS
QUALITY ASSURANCE ANNUAL REPORT
CALENDER YEAR 2009

FINAL

Environmental Protection Agency
Office of Air Quality, Planning and Standards
Air Quality Analysis Division
109 TW Alexander Drive
Research Triangle Park, NC 27711


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FORWARD

In Spring of 2011, Research Triangle Institute (RTI) prepared a technical report under Contract
No. EP-D-08-047 Work Assignment 03-04. The report describes the Quality Assurance (QA)
data collected within the calendar year 2009. The report was prepared for Dennis K. Mikel,
Work Assignment Manager within the Office of Air Quality Planning and Standards (OAQPS)
in Research Triangle Park, North Carolina. The draft report was written by Larry Michael and
Jeff Nichols of RTI. EPA staff submitted it to the State and Local air toxics community for
review and comment. RTI addressed the comments that were submitted and sent this final report
to the Work Assignment Manager. This is the final report.

Additional work on this report was provided by AQAD staff.

Comments and questions should be submitted to:

Dennis K. Mikel
EPA-OAQPS-AQAD
919-541-5511 or;
mikel. denni sk@epa. gov


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NATIONAL AIR TOXICS TRENDS STATIONS
QUALITY ASSURANCE ANNUAL REPORT
CALENDAR YEAR 2009

FINAL REPORT

Prepared by:
RTI International

For:

U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Air Quality Analysis Division
109 TW Alexander Drive
Research Triangle Park, NC 27711

Under:

U.S. EPA Contract EP-D-08-047
Work Assignment 03-04, Task 10


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ACKNOWLEDGEMENTS

This report was prepared by RTI International, under Work Assignment 03-04, Task 10 for EPA
contract EP-D-08-047. Substantial contributions to the determination of the laboratories
associated with specific monitoring sites and to the acquisition of proficiency testing results were
provided by Dennis Mikel and Mike Jones of U.S. EPA.


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TABLE OF CONTENTS

Section	Page

1.0 Introduction	1

2.0 NATTS Quality Assurance Data for Calendar Year 2009 	2

2.1	Measurement Quality Objectives	5

2.2	Completeness of NATTS Data	6

2.3	Precision of NATTS Data	11

2.3.1	Analytical Precision Results	16

2.3.2	Overall Precision Results	17

2.4	Laboratory Bias Data Based on Proficiency Testing Samples	35

2.5	Flow Audit Results from Instrument Performance Audits	39

2.6	Method Detection Limit Data	42

3.0 Summary	53

4.0 Recommendations	54

5.0 References	55

LIST OF TABLES

Number	Page

Table 1. EPA Region Numbers, NATTS Sites, Site Type, and Air Quality Systems Site

Codes	3

Table 2. The 23 Unique Hazardous Air Pollutants51 and their Air Quality Systems

Parameter Codes	4

Table 3. Measurement Quality Objectives for the NATTS Program	5

Table 4. Data Sources Used to Evaluate Measurement Quality Objectives	5

Table 5. Percentage Completeness51 of the 2009 AQS Dataset by Site for Seven

Hazardous Air Pollutants	7

Table 6. Parameter Occurrence Codes by NATTS Site and Analyte Type	14

Table 7. Laboratories Performing Analyses for the Different Analyte Types for Each

NATTS Site in 2009	15

Table 8. Laboratory Abbreviations and Descriptions for NATTS Laboratories	16

Table 9. Analytical Precision51 for Replicate Analyses of 2009 NATTS Data	18

Table 10. Overall Precision51 for Primary and Collocated Samples from 2009	25

Table 11. Performance Testing Bias Results51 for VOCs in 2009 NATTS Laboratories	36

Table 12. Proficiency Testing Bias Results51 for Carbonyls in 2009 NATTS Laboratories	37

Table 13. Proficiency Testing Bias51 Results for Metals in 2009 NATTS Laboratories	38

Table 14. Proficiency Testing Program Participation for 2009	39

Table 15. Flow Audit Results from 2009 Instrument Performance Audits	40


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Table 16. Method Detection Limits by Site and Overall for Calendar Year 2009 (VOCs

and Carbonyls: (J,g/m3; Metals: ng/m3)	45

Table 17. Comparison of Method Detection Limits Reported by ERG Laboratory for

Metals between High- and Low-Volume Samplers in Calendar Year 2009	53

Table 18. Summary Statistics for Method Detection Limits across All Reporting NATTS

Laboratories for 2009	53

LIST OF FIGURES

Figure 1. Completeness for Benzene at NATTS Sample Collection Sites in 2009 (MQO

reference indicated at 85%)	8

Figure 2. Completeness for 1,3-Butadiene at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%)	8

Figure 3. Completeness for Acrolein at NATTS Sample Collection Sites in 2009 (MQO

reference indicated at 85%)	9

Figure 4. Completeness for Formaldehyde at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%)	9

Figure 5. Completeness for Naphthalene at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%)	10

Figure 6. Completeness for Chromium (VI) at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%)	10

Figure 7. Completeness for Arsenic at NATTS Sample Collection Sites in 2009 (MQO

reference indicated at 85%)	11

Figure 8. Analytical Precision Summary for Benzene at NATTS Sample Collection Sites

in 2009 (MQO reference indicated at 15%)	21

Figure 9. Analytical Precision Summary for 1,3-Butadiene at NATTS Sample Collection

Sites in 2009	21

Figure 10. Analytical Precision Summary for Acrolein at NATTS Sample Collection

Sites in 2009 (MQO reference indicated at 15%)	22

Figure 11. Analytical Precision Summary for Formaldehyde at NATTS Sample

Collection Sites in 2009	22

Figure 12. Analytical Precision Summary for Naphthalene at NATTS Sample Collection

Sites in 2009	23

Figure 13. Analytical Precision Summary for Chromium (VI) at NATTS Sample

Collection Sites in 2009 (MQO reference indicated at 15%)	23

Figure 14. Analytical Precision Summary for Arsenic at NATTS Sample Collection Sites

in 200 	24

Figure 15. Overall Precision Summary for Benzene at NATTS Sample Collection Sites in

200 (MQO reference indicated at 15%)	32

Figure 16. Overall Precision Summary for 1,3-Butadiene at NATTS Sample Collection

Sites in 2009 (MQO reference indicated at 15%)	32

Figure 17. Overall Precision Summary for Acrolein at NATTS Sample Collection Sites in

2009 (MQO reference indicated at 15%)	33

Figure 18. Overall Precision Summary for Formaldehyde at NATTS Sample Collection

Sites in 2009 (MQO reference indicated at 15%)	33

Figure 19. Overall Precision Summary for Naphthalene at NATTS Sample Collection

Sites in 2009 (MQO reference indicated at 15%)	34


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Figure 20. Overall Precision Summary for Chromium (VI) atNATTS Sample Collection

Sites in 200 (MQO reference indicated at 15%)	34

Figure 21. Overall Precision Summary for Arsenic at NATTS Sample Collection Sites in

2009 (MQO reference indicated at 15%)	35

Figure 22. Distribution of Laboratory Bias by Analyte for Proficiency Testing Data from

200 	39

Figure 23. Summary of Instrument Performance Flow Audit Results for 2009	43

Figure 24. Distribution of Method Detection Limits for Carbonyls for 2009 NATTS Data
(dashed line indicates MQO target MDL for formaldehyde; > 1.5 x IQR are

identified as blue stars in top display)	47

Figure 25. Distribution of Method Detection Limits for Metals for 2009 NATTS Data

(dashed line indicates MQO target MDL for arsenic; > 1.5 x IQR are identified as

blue stars in top display)	48

Figure 26. Distribution of Method Detection Limits for Arsenic for 2009 NATTS Data

(dashed line indicates MQO target MDL for arsenic	49

Figure 27. Distribution of Method Detection Limits for VOCs for 2009 NATTS Data

(dashed line indicates MQO target MDL for benzene; > 1.5 x IQR are identified

as blue stars in top display)	50

Figure 28. Distribution of Method Detection Limits for PAHs for 2009 NATTS Data	51


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1.0 INTRODUCTION

As mandated under the Government Performance Results Act, the U.S. Environmental
Protection Agency (EPA) is focused on reducing risk of cancer and other serious health effects
associated with hazardous air pollutants (HAPs) by achieving a 75% reduction in air toxics
emissions chemicals, based on 1993 levels. The current inventory of HAPs includes 188
chemicals regulated under the Clean Air Act that have been linked to numerous adverse human
health and ecological effects, including cancer, neurological effects, reproductive effects, and
developmental effects. Current agency attention is targeting risk reduction associated with
human exposure to air toxics.

The National Air Toxics Trends Station (NATTS) network was established to create a
database of air quality data to assess progress in reducing ambient concentrations of air toxics
and concomitant exposure-associated risk. During 2009, the NATTS network consisted of
27 stations in the contiguous 48 states. To ensure the quality of the data collected under the
NATTS network, EPA has implemented a Quality System comprising two primary components:
(1) Technical Systems Audits (TSAs) and (2) Instrument Performance Audits (IPAs) for both the
network stations and the associated sample analysis laboratories. As an integral part of the
Quality System, EPA has also instituted semiannual analysis of proficiency testing (PT) samples
for volatile organic compounds (VOCs) and carbonyls and annual analysis of PT samples for
metals and polycyclic aromatic hydrocarbons (PAHs) to provide quantitative assessment of
laboratory performance and to ensure that sampling and analysis techniques are consistent with
precision, bias, and method detection limits (MDLs) specified by the NATTS Measurement
Quality Objectives (MQOs).

This report describes and summarizes the quality assurance (QA) data generated by the
NATTS program during calendar year 2009. For data retrieved from EPA's Air Quality Systems
(AQS) database, only data collected in 2009 and posted prior to August 31, 2011, are included.
Although this report contains substantive information about air concentrations of 2 different
chemicals of interest, it focuses primarily on results for four classes of toxic ambient air
constituents (VOCs, carbonyls, PAHs, and PMi0 metals) as represented by seven pollutants:
benzene, 1,3-butadiene, formaldehyde, acrolein, naphthalene, chromium (VI), andPMio arsenic.
At the request of EPA, these seven pollutants were selected as having particular interest by virtue
of associated health risk and the frequency of their occurrence at measurable concentrations.
Although no group of compounds can provide unequivocal representation of their respective
compound groups, these seven analytes were selected by EPA as reasonable representatives of
the four main categories of HAPs routinely measured in the NATTS program and thus provide
the framework for this summary report. It is presumed that if the NATTS program can meet the
Data Quality Objectives (DQOs) for these seven compounds, the additional 20 compounds of
concern will be of comparable quality by virtue of the representativeness of the physicochemical
properties and the consistency of the collection and analysis methodologies of these seven
compounds. Because monitoring for PAHs and chromium (VI) is new, or relatively new, at
many sites, QA results may be unavailable for some MQOs at some sites.

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The comprehensive information in this Quality Assurance Annual Report (QAAR) was
compiled from data acquired from numerous sources. The following general categories of
information are presented:

•	Descriptive background information on the AQS site identities, compounds of
interest, and MQOs;

•	Assessment of the completeness of the data available in the AQS database;

•	Precision estimates, independently, for analytical and overall sampling error
computed for as many of the 27 applicable compounds and for as many of the
27 NATTS sites as available for calendar year 2009;

•	Evaluation of an analytical laboratory's accuracy (or bias), based on analysis of blind
audit PT samples for many of the 27 compounds;

•	Field bias data, which are expressed as the differences between actual and measured
sampler flow readings for each of the four different sampler types associated with
VOCs, carbonyls, PAHs, and PMi0 metals, for primary and collocated samplers
(where available) at the three sites visited during the IP As conducted during calendar
year 2009; and

•	MDL data for each site and/or analytical laboratory. The AQS database, specifically
the ALTMDL variable, was used as the primary source of MDLs for 2009.

However, because this MDL field in AQS is not a required field, it was necessary to
augment the information with direct contacts to several NATTS state and local
agencies and affiliated laboratories to compile MDL data for the 27 compounds of
interest at all sites. This modification improved both acquisition efficiency and the
accuracy of the MDL data.

Where possible, all data analyses were performed in SAS, version 9.2. Method Detection
Limits obtained from individual laboratories and Proficiency Testing data wwere recorded and
compiled using Microsoft Excel.

2.0 NATTS QUALITY ASSURANCE DATA FOR CALENDAR YEAR 2009

The NATTS network included 27 sites in 2009. Table 1 presents the EPA Regions in
which the sites are located, a descriptive location of the sites (site identifier), the urban or rural
character of each site, and the unique AQS identification code [1],

Although a city and state are typically used as the site identifier, the county name is used
for the two Florida sites on either side of Tampa Bay and for Harrison County, TX. Historical
consistency has been maintained for the Grand Junction, CO, site, where two separate codes are
used, one for VOCs, carbonyls, and PAHs (-0018) and the other for metals (-0017). This
convention is unique to this site and is used because the organics and metals samplers are present
at two separate physical locations at the sampling site.

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Table 1. EPA Region Numbers, NATTS Sites, Site Type, and Air Quality Systems Site

Codes.

EPA Region

Site Identifier

Type

AQS Site Code

1

Boston-Roxbury, MA

Urban

25-025-0042

1

Underbill, VT

Rural

50-007-0007

1

Providence, Rl

Urban

44-007-0022

II

Bronx, NY

Urban

36-005-0110

II

Rochester, NY

Urban

36-055-1007

III

Washington, DC

Urban

11-001-0043

III

Richmond, VA

Urban

51-087-0014

IV

Chesterfield, SC

Rural

45-025-0001

IV

Decatur, GA

Urban

13-089-0002

IV

Grayson Lake, KY

Rural

21-043-0500

IV

Hillsborough County, FL

Urban

12-057-3002

IV

Pinellas County, FL

Urban

12-103-0026

V

Dearborn, Ml

Urban

26-163-0033

V

Mayvilie, Wl

Rural

55-027-0007

V

Northbrook, IL

Urban

17-031-4201

VI

Deer Park, TX

Urban

48-201-1039

VI

Harrison County, TX

Rural

48-203-0002

VII

St. Louis, MO

Urban

29-510-0085

VIII

Bountiful, UT

Urban

49-011-0004

VIII

Grand Junction, CO

Rural

08-077-0017a, -0018b

IX

Phoenix, AZ

Urban

04-013-9997

IX

San Jose, CA

Urban

06-085-0005

IX

Rubidoux, CA

Urban

06-065-8001

IX

Los Angeles, CA

Urban

06-037-1103

X

La Grande, OR

Rural

41-061-0119

X

Portland, OR

Urban

41-051-0246

X

Seattle, WA

Urban

53-033-0080

' Metals only.

b VOCs, carbonyls, PAHs, and Cr(VI) only.

The 27 specific HAPs measured in the NATTS program, presented in Table 2 along with
their unique AQS identification codes, are compounds that EPA has identified as being of
significant health concern. These include 16 VOCs, 2 carbonyls, 2 PAHs, 6 PMio metals, and
chromium (VI). Succinct abbreviations of each chemical name are provided to facilitate table
and figure creation and interpretation throughout this report.

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Table 2. The 23 Unique Hazardous Air Pollutants" and their Air Quality Systems

Parameter Codes.

Analyte





AQS

Compound

Abbreviation3

Compound Name

Exact AQS Label

Code

Group

BENZb

benzene

Benzene

45201

voc

BUTAb

1,3-butadiene

1,3-Butadiene

43218

voc

CTET

carbon tetrachloride

Carbon Tetrachloride

43804

voc

CLFRM

chloroform

Chloroform

43803

voc

EDB

1,2-dibromoethane

Ethylene Dibromide

43843

voc

DCP

1,2-dichloropropane

1,2-Dichloropropane

43829

voc

EDC

1,2-dichloroethane

Ethylene Dichloride

43815

voc

MECL

dichloromethane

Dichloromethane

43802

voc

TCE1122

1,1,2,2-tetrachloroethane

1,1,2,2-Tetrachloroethane

43818

voc

PERC

tetrachloroethylene

Tetrachloroethylene

43817

voc

TCE

trichloroethylene

Trichloroethylene

43824

voc

VCM

vinyl chloride

Vinyl Chloride

43860

voc

cDCPEN

cis-1,3-dichloropropene

Cis-1,3-Dichloropropylene

43831

voc

tDCPEN

trans-1,3-dichloropropene

Trans-1,3-Dichloropropylene

43830

voc

ACROc,e

acrolein

Acrolein

43505d

VOCc

ACROd,e

acrolein

Acrolein

435098

VOCc

ACRY

acrylonitrile

Acrylonitrile

43704

voc

NAPHb

naphthalene

Naphthalene (Tsp) Stp



PAH

BaP

benzo[a]pyrene

Benzo[A]Pyrene (Tsp) Stp



PAH

FORMb

formaldehyde

Formaldehyde

43502

Carbonyl

ACET

acetaldehyde

Acetaldehyde

43503

Carbonyl

Asb

arsenic

Arsenic Pm10 Stp

82103

Metal

Be

beryllium

Beryllium Pm10 Stp

82105

Metal

Cd

cadmium

Cadmium Pm10 Stp

82110

Metal

Pb

lead

Lead Pm10 Stp

82128

Metal

Mn

manganese

Manganese Pm10 Stp

82132

Metal

Ni

nickel

Nickel Pm10 Stp

82136

Metal

CrVlb

chromium (VI)

Chromium (VI) Tsp Stp

12115

Metal

Asf

arsenic

Arsenic Pm10 Lc

85103

Metal

Bef

beryllium

Beryllium Pm10 Lc

85105

Metal

Cdf

cadmium

Cadmium Pm10 Lc

85110

Metal

Pbf

lead

Lead Pm10 Lc

85128

Metal

Mnf

manganese

Manganese Pm10 Lc

85132

Metal

Nif

nickel

Nickel Pm10 Lc

85136

Metal

CrVlf

chromium (VI)

Chromium (VI) Tsp Lc

14115

Metal

a Mercury has been intentionally excluded from all data analyses in this report, per U.S. EPA directive.
b Results presented are representative of completeness for other chemicals in this class.
c Unverified results.

11 Verified results.

e Completeness based on verified and unverified results.

f Some sites reported results for metal analytes at local conditions (Lc), instead of STP (Stp), using these parameter codes. For this report, data
reported in Stp and Lc units are combined, under the assumption that the difference between the two values is negligible.

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2.1 Measurement Quality Objectives

MQOs for completeness, precision, laboratory bias, and MDLs, established for the
NATTS network to ensure data quality within the network, were unchanged from 2008 and were
based on the Technical Assistance Document [2] applicable on January 1, 2009. The stated DQO
for the NATTS program is "to be able to detect a 15 percent difference (trend) between two
consecutive 3-year annual mean concentrations within acceptable levels of decision error" [3],
MQOs for the four compounds of primary importance to the NATTS program (benzene, 1,3-
butadiene, formaldehyde, PMi0 arsenic) are summarized in Table 3. MQOs for the three
additional analytes of interest (acrolein, naphthalene, and chromium [VI]) have not been
assigned by EPA.

Table 3. Measurement Quality Objectives for the NATTS Program.

Compound

Completeness

Precision
(Coefficient of
Variation)

Laboratory Bias

Method Detection
Limit (MDL)

benzene

> 85%

< 15%

< 25%

0.016 |jg/m3

1,3-butadiene

> 85%

< 15%

< 25%

0.013 |jg/m3

formaldehyde

> 85%

< 15%

< 25%

0.0074 |jg/m3a

arsenic

> 85%

< 15%

< 25%

0.217 ng/m3b

a Assumes a sampling volume of 1,000 L.

b Assumes high-volume sampling with a sampling volume of 1,627 m3 (1.13 m3/min [40 ft3/min] for 24 hours) and that one-eighth of the sampled
area of the filter is extracted for analysis.

As intended by the NATTS network, the MQOs require that

(1)	sampling occurs every 6th day;

(2)	sampling is successful 85% of the time;

(3)	precision, as measured by the coefficient of variation (CV), is within 15% based on
duplicate and collocated samples; and

(4)	laboratory (measurement) bias is less than 25%, based on laboratory PT results.

Furthermore, actual MDLs, as reported by the laboratories supporting the NATTS sites or
their sponsoring federal, state, or municipal agencies, are compared with the target MDLs as
listed in the applicable edition of the NATTS Technical Assistance Document (TAD) [2],

Data acquired to assess compliance with the above stated MQOs were derived from a
variety of sources. These sources are given in Table 4.

Table 4. Data Sources Used to Evaluate Measurement Quality Objectives.

Measurement Quality Objective

Data Source

Completeness

AOS

Analytical and Overall Precision

AOS

Bias—Laboratory

Proficiency testing results reported by Alion

Bias—Field

Audits of sampler flow rates conducted by RTI International

MDL

AOS augmented with information from the analytical laboratories

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Data retrievals from AQS for relevant samples collected in 2009 and uploaded to the
AQS database prior to May 7, 2011, were analyzed to assess completeness and to estimate
precision from results of replicate analyses and collocated and duplicate sampling. PT samples
were distributed by EPA contractor Alion Science, Inc., to participating laboratories for
determination of analytical bias. Field bias was evaluated by independent measurement of
sampler flow rates with National Institute of Standards and Technology (NIST)-traceable
flowmeters during on-site IP As. Finally, MDL data were extracted from AQS, where present,
and augmented by values obtained by direct contact with the individual laboratories.

2.2 Completeness of NATTS Data

The AQS database was queried for data records corresponding to relevant samples
collected from the 27 NATTS sites during calendar year 2009 and entered into the AQS database
prior to May 7, 2011. This posting period to AQS was extended from the original July 1, 2010
deadline for the 2009 report to allow for posting of data unintentionally excluded by a single
NATTS site. Any data that might have been contributed to AQS by participating laboratories
after May 7, 2011, are not reflected in the completeness calculations presented in Table 5 below.
Specifically, completeness of the 2009 AQS dataset was assessed for seven compounds
representative of the entire suite of 27 compounds presented previously in Table 2: benzene, 1,3-
butadiene, acrolein, formaldehyde, naphthalene, chromium (VI), and arsenic. Based on the
NATTS requirement of a l-in-6 day sample collection frequency, 60 records for the primary
parameter occurrence code (POC) would represent 100% completeness. Depending on the first
date of collection in 2009, some sites might exhibit slightly greater than 100% completeness if
61 samples were collected during that year. For purposes of this completeness calculation, non-
detects were counted equivalently with measurable values. Conversely, missing values were not
counted toward the percentage complete. Completeness statistics were not adjusted for
abbreviated collection periods because all sites were operated for the entire 12 months during
2009.

Completeness statistics were computed for primary samples or, if the primary
measurement was missing, for the collocated samples collected at the same location during the
same sampling period. To ensure that only a single record was included for each site and date,
the maximum value of the measurements was retained across primary and collocated samples. In
this way, if one of the measurements was missing and the other was not detected/measured, the
maximum would capture the not detected/measured record. If both primary and collocated
records contained a missing value, only one record would be tallied for the completeness count.
Finally, if both records contained a not detected or measured value, the larger of the two would
be captured for the completeness count. Because sample collection at some locations was
performed more frequently to meet the requirements of other sampling networks or for other
specific purposes, only records that occurred at the required l-in-6 day sample collection
frequency (days 0, 6, 12, 18, 24, 30, etc.), starting with the first collection date for each site in
calendar year 2009, were counted. For this and other reasons, it is not possible to discern from
the AQS database when makeup samples are collected. The individual enumeration of valid
samples from each and every site would be an extremely tedious task and presumes that only
NATTS sample records are present in the database for a given parameter occurrence code.
Therefore, to account for makeup samples collected near the time of the scheduled collection
date, the interval of days since the last collection event was allowed to vary between 4 and 8. No

6


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correction was applied for compound-specific missing data (e.g., the value for benzene was
missing, but the value for dichloromethane was non-missing). It is assumed that this discrepancy
does not significantly distort the percentage completeness.

The results of the completeness assessment are presented for each collection location and
representative compound in Table 5 and in Figures 1 through 7. Mean and median completeness
values across all NATTS laboratories for a given analyte and across all analytes for a given site
are also presented. In cases where no data were reported, the particular analyte class was not
collected at that NATTS site, as indicated by table notes.

Table 5. Percentage Completeness" of the 2009 AQS Dataset by Site for Seven Hazardous

Air Pollutants.



Parameter Code -ป

45201

43218

43502

43505

17141

12115

82103

AQS Site ID

Site Name

BENZ

BUTA

FORM

ACRO

NAPH

CRVI

AS

25-025-0042

Boston-Roxbury, MA

97

97

102

97

100

98

95

49-011-0004

Bountiful, UT

95

95

95

95

100

97

92

36-005-0110

Bronx, NY

102

102

102

102

97

98

102

45-025-0001

Chesterfield, SC

102

102

102

102

102

100

102

26-163-0033

Dearborn, Ml

93

93

97

93

97

97

102

13-089-0002

Decatur, GA

102

102

102

102

100

95

102

48-201-1039

Deer Park, TX

102

102

98

102

100

100

102

08-077-0017b, -0018ฐ

Grand Junction, CO

85

85

95

85

98

98

102

21-043-0500

Grayson Lake, KY

93

93

87

93

97

98

95

48-203-0002

Harrison County, TX

100

100

97

97

95

98

102

12-057-3002

Hillsborough County, FL

100

100

100

100

102

102

102

41-061-0119

La Grande, OR

93

93

97

NRd

98

92

88

06-037-1103

Los Angeles, CA

100

100

100

100

100

NR

NR

55-027-0007

Mayville, Wl

88

88

92

88

98

97

72

17-031-4201

Northbrook, IL

102

102

102

102

97

100

102

04-013-9997

Phoenix, AZ

95

95

98

95

95

97

95

12-103-0026

Pinellas County, FL

102

102

102

102

98

102

102

41-051-0246

Portland, OR

77

90

102

NR

95

100

98

44-007-0022

Providence, Rl

102

102

102

102

90

102

102

51-087-0014

Richmond, VA

100

100

102

100

100

100

100

36-055-1007

Rochester, NY

102

102

102

102

100

100

102

06-065-8001

Rubidoux, CA

98

98

102

98

95

NR

NR

06-085-0005

San Jose, CA

93

93

102

93

102

NR

100

53-033-0080

Seattle, WA

93

93

93

93

97

100

93

29-510-0085

St. Louis, MO

102

102

100

102

95

97

102

50-007-0007

Underhill, VT

102

102

102

102

97

98

102

11-001-0043

Washington, DC

100

100

NR

100

97

102

102



Mean

97

98

99

98

98

99

98



Std. Dev.

6

5

4

5

3

2

7



Median

100

100

101

100

98

98

102

' Data pulled from AQS on 8/31/2011.
Metals only.

Carbonyls, VOCs, and PAHs only.
11 Not reported for this site.

7


-------
CMPDALIAS = BENZ

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinellas Counly, FL
Portland, OR
Providence, Rl
Ftichmond, VA
Rochester, NY
Rubidoux, CA
San Jose, CA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

10

20

30

40

50

60

70

80

90 100

110

Percent Complete

Figure 1. Completeness for Benzene at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

CMPDALIAS = BUTA

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA
Mayville, Wl
Noilhbrook, IL
Phoenix, AZ
Pinellas County, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
San Jose, CA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

10

20 30

40

50

60

70

80 90 100 110

Percent Complete

Figure 2. Completeness for 1,3-Butadiene at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

8


-------
CMPDALIAS=ACRO

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
Los Angeles, CA
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinellas Counly, FL
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
San Jose, CA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

10

20 30

40

50

60

70

80

90 100 110

Percent Complete

Figure 3. Completeness for Acrolein at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

CMPDALIAS=FORM

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO

Grayson Lake, KY		

Harrison County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA

Mayville, Wl		

Northbrook, IL
Phoenix, AZ
Pinellas County, FL
Portland, OR

Providence, Rl	1

Richmond, VA

Rochester, NY

Rubidoux, CA

San Jose, CA

Seattle, WA

St. Louis, MO

Underhill. VT

I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I	| i i i i | i i i i |

0 10 20 30 40 50 60 70 80 90 100 110

Percent Complete

Figure 4. Completeness for Formaldehyde at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

9


-------
CM PDALI AS = NAPH

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinellas Counly, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
San Jose, CA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

10

20

30

40

50

60

70

80

90 100

110

Percent Complete

Figure 5. Completeness for Naphthalene at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

CMPDALIAS=CRVI

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
La Grande, OR
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinellas Counly, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

10

20 30

40

50

60

70

80 90 100 110

Percent Complete

Figure 6. Completeness for Chromium (VI) at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

10


-------
Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Harrison County, TX
Hillsborough County, FL
La Grande, OR
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinellas County, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
San Jose, CA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

0 10 20 30 40 50 60 70 80 90 100 110

Percent Complete

Figure 7. Completeness for Arsenic at NATTS Sample Collection Sites in 2009

(MQO reference indicated at 85%).

With the exceptions of benzene at the Portland, OR site and arsenic at the Mayville, WI,
site, all sites exhibited consistently high completeness statistics for all analytes and met the MQO
of 85% completeness. The preponderance of completeness metrics at 102% reflects the fact that
most sites collected 61 samples during 2009 and completeness is based on the collection of 60
samples.

2.3 Precision of NATTS Data

Three basic sample types are collected at NATTS sites:

•	Primary samples—a single sample that represents a particular sampling event.

•	Duplicate samples—a replicate sample, collected simultaneously with the primary
sample, that represents a second measurement from the same sample stream (e.g., the
inlet stream of an outdoor air monitor) but employs an independent sample collection
device (e.g., sampling pump) and collection substrate (e.g., filter) from the primary
sample. Duplicate samples provide the basis for assessing the aggregate variability
associated with the collection device, sampling substrate, and sample analysis.

•	Collocated samples—a replicate sample, collected simultaneously with the primary
sample, that represents a second measurement from a completely independent (but
spatially close, usually 1 to 2 meters away from the primary sampler) sample stream,
collection device, and collection substrate from the primary sample. Collocated
samples provide the basis for assessing the total variability associated with all

CMPDALIAS = AS

11


-------
components of the sample collection and analysis scheme; thus, the analyst can
assume that the air collected by the primary and collocated samplers is absolutely
identical in its composition. Samples collected at different sites violate this basic
premise of collocation and were excluded from these precision analyses at the
direction of EPA.

•	Replicate Sampling:

Replicate sampling refers, generally, to both duplicate and collocated sample collections
as described above and as differentiated within the AQS database. Precision assessments
associated with replicate sampling are distinctly different from those associated with replicate
analyses as the latter are derived from a second chemical analysis of a single sample and the
former are derived from single chemical analyses of two different samples. For this report,
precision analyses were performed exclusively on NATTS sites; surrogate, non-NATTS sites
with collocated samplers have not been included. The methodological precision for the NATTS
data was assessed from both analytical (i.e., instrumental) and overall (i.e., instrumental +
sampling) perspectives. Analytical precision measures the variability in reported results due
exclusively to differences in analytical instrument performance and was estimated by comparing
results from two analyses of a single sample, whether that sample be primary, duplicate, or
collocated. Overall sampling precision was assessed by comparing the results from primary and
collocated samples or from primary and duplicate samples and accounts for the combined
variability associated with sample collection and sample analysis. Despite the differences, albeit
subtle, between duplicate and collocated samples, this report provides separate overall precision
estimates for these two replicate sample types.

For the purposes of these precision assessments, the AQS database was queried for two
distinct record types: RP records and RD records. RP records contain data for various types of
replicate samples and analyses associated with a particular sampling date, site, and chemical
parameter. Different types of replicates are identified by the value of the precision ID variable
(PRECISID) according to the following scheme:

•	PRECISID = 1: Collocated sample data

•	PRECISID = 2: Replicate analysis of a primary sample

•	PRECISID = 3: Replicate analysis of a collocated sample

With the exception of the Pinellas County, FL site, analytical precision for this report
was computed from the replicate pairs of data coded with either Precision Id. 2 or 3. Additional
Precision Ids. were employed for Pinellas County. Overall precision was computed using the
data in the raw data records as described below.

In addition to the replicate records, raw data (AQS RD) transactions provide a second
source of primary and collocated data in AQS. Using the POCs shown for each NATTS site
listed in Table 6, it is possible to distinguish among primary, duplicate, and collocated sampling
events. For example, primary samples collected at the Chesterfield, SC, NATTS site are assigned
a parameter occurrence code of 1, while collocated samples collected at the same site are
assigned a parameter occurrence code of 2. This results in the creation of two distinct records for
each sampling event at which a collocated sample is collected. Duplicate samples are similarly

12


-------
identified. Because the assignment of a particular POC is made at the discretion of each NATTS
site, extensive effort was required to ensure that the POCs for each site were correctly identified.
POCs for primary, duplicate, and collocated samples of each chemical class were determined by
hierarchical exploration of three principal pieces of information:

1)	POCs used by each NATTS collection site in 2007 and 2008 were used as the
reference for POCs assigned in 2009.

2)	POCs assigned in previous years were confirmed by results of frequency analysis
performed on RD records for samples collected in 2009.

3)	Discrepancies and/or uncertainties about POC assignments were resolved by direct
contact with NATTS administrators for specific collection sites.

Multiple POCs for a given site, analyte, and sample type reflect a number of factors
unique to a site during 200 , largely made for reasons known only to the NATTS site
administrators. Overall precision estimates were computed by comparing primary and collocated
records for a particular site, chemical parameter, and sample collection date.

13


-------
Table 6. Parameter Occurrence Codes by NATTS Site and Analyte Type.













Parameter Occurrence Codes (POCs)3































Chromium





AQS Site



voc



Carbonyls

Metals



PAHs





(VI)

Region

Site Identifier

Code

Pb

Dc

Cd

P

D

C

P D C

P

D

C

P

D C

1

Boston, MA

25-025-0042

10

11



3

4



6 7

6





6

7

1

Underhill, VT

50-007-0007

1





1





1

6





6

7

1

Providence, Rl

44-007-0022

2





5



7

1 2

6





6

7

II

Bronx, NY

36-005-0110

2





2





1 2

6





6

7

II

Rochester, NY

36-055-1007

2





2





1

6





6

7

III

Washington, DC

11-001-0043

4





1





1

1





1

2

III

Richmond, VA

51-087-0014

4

1



2





1

6





6

7

IV

Chesterfield, SC

45-025-0001

1



2

1



2

1 2

6





6

7

IV

Decatur, GAe

13-089-0002

1,3



2,4

2



3

1 2

6



7

6

7

IV

Grayson Lake, KY

21-043-0500

1

2



1

2



1 2

6





6

7

IV

Hillsborough
County, FL

12-057-3002

1





6





5

6



7

6

7

IV

Pinellas County,
FL

12-103-0026

1





6





5

6



7

6

7

V

Dearborn, Ml

26-163-0033

1



2

1



2

1 9

1



2

1

2

V

Mayville, Wl

55-027-0007

1





1

2



1 2

6





6

7

V

Northbrook, IL

17-031-4201

6



7

6



7

6 7

6





6

7

VI

Deer Park, TX

48-201-1039

2



3

3





1

1

2

6

1

2

VI

Harrison County,
TX

48-203-0002

1





1





1

1





1



VII

St. Louis, MO

29-510-0085

6





6





6 7

6





6

7

VIII

Bountiful, UT

49-011-0004

6





6





1 2

6





6

7

VIII

Grand Junction,
CO

08-077-0017,
-0018

6





6





3 4

6





6

7

IX

Phoenix, AZ

04-013-9997

6



7

30



31

1

3





6

7

IX

Los Angeles, CA

06-037-1103

4



5

4



5



6









IX

Rubidoux, CA

06-065-8001

4



5

4



5



6

7







IX

San Jose, CA

06-085-0005

3



5

3



1

1

1









X

La Grande, OR

41-061-0119

7





7





7

7





7



X

Portland, OR

41-051-0246

7



9

7



9

7 9

7



9

7



X

Seattle, WA

53-033-0080

6



7

6



7

6 7

6

7



6

7

a As reported by the NATTS site administrator. Multiple POCs reflect different analytes or changes in assignments during the monitoring year.
b P = Primary
c D = Duplicate
11 C = Collocated

e Benzene on POCs 3 and 4; all other VOCs on POCs 1 and 2.

14


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Table 7, complemented by Table 8, presents the laboratories that analyzed specific
sample types for each NATTS site. Of particular note is the fact that some laboratories provided
analytical chemistry services for multiple NATTS sites. Laboratory codes presented in Table 8
were assigned by Alion Science, Inc., to track PT samples and their results.

Table 7. Laboratories Performing Analyses for the Different Analyte Types for Each

NATTS Site in 2009.

Site Identifier

VOCsa

Carbonyls

Metals

PAHs

Chromium (VI)

Boston-Roxbury, MA

RIDOH

MADEP

ERG

ERG

ERG

Underbill, VT

ERG

VTDEC

ERG

ERG

ERG

Providence, Rl

RIDOH

RIDOH

RIDOH

ERG

ERG

Bronx, NY

NYSDEC

NYSDEC

RTI

ERG

ERG

Rochester, NY

NYSDEC

NYSDEC

RTI

ERG

ERG

Washington, DC

MDE

PAMSL

WVDEP

ERG

ERG

Richmond, VA

VA DCLS

VA DCLS

VA DCLS

ERG

ERG

Chesterfield, SC

SCDHEC

SCDHEC

SCDHEC

ERG

ERG

Decatur, GA

GADNR

GADNR

GADNR

ERG

ERG

Grayson Lake, KY

KYDES

KYDES

KYDES

ERG

ERG

Hillsborough County, FL

PCDEM

ERG

EPCHC

ERG

ERG

Pinellas County, FL

PCDEM

ERG

EPCHC

ERG

ERG

Dearborn, Ml

ERG

ERG

MIDEQ

ERG

ERG

Mayville, Wl

WSLH

WSLH

WSLH

ERG

ERG

Northbrook, IL

ERG

ERG

ERG

ERG

ERG

Deer Park, TX

TCEQ

TCEQ

TCEQ

TCEQ

TCEQ

Harrison County, TX

TCEQ

TCEQ

TCEQ

TCEQ

TCEQ

St. Louis, MO

ERG

ERG

ERG

ERG

ERG

Bountiful, UT

ERG

ERG

ERG

ERG

ERG

Grand Junction, CO

ERG

ERG

IMLASb

ERG

ERG

Phoenix, AZ

ERG

ERG

ERG

ERG

ERG

San Jose, CA

BAAQMD

BAAQMD

ERG

ERG

CARB

Rubidoux, CA

SCAQMD

SCAQMD

SCAQMD

ERG

CARB

Los Angeles, CA

SCAQMD

SCAQMD

SCAQMD

ERG

CARB

La Grande, OR

ODEQ

ODEQ

ODEQ

ODEQ

ODEQ

Portland, OR

ODEQ

ODEQ

ODEQ

ODEQ

ODEQ

Seattle, WA

ERG

ERG

ERG

ERG

ERG

a Includes acrolein.

b Switching from IMLAS to CO State Lab effective January 2010.

15


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Table 8. Laboratory Abbreviations and Descriptions for NATTS Laboratories.



Laboratory



Laboratory Code(s)

Abbreviation

Laboratory Description

01-01-C,V,M

RIDOH

Rhode Island Department of Health

01-02-C,V

VTDEC

Vermont Department of Environmental Conservation

01-03-C

MADEP

Massachusetts Department of Environmental Protection

01-04-M

USEPAR1

U.S. EPA Region 1 Laboratory

02-01-C,V

NYSDEC

New York State Department of Environmental Conservation

03-01-V

MDE

Maryland Department of the Environment

03-01-C

PAMSL

Philadelphia Air Management Services Laboratory

03-01-M

WVDEP

West Virginia Department of Environmental Protection

04-01-M

EPCHC

Environmental Protection Commission of Hillsborough County

04-01-V

PCDEM

Pinellas County Department of Environmental Management

04-02-C,M,V,P

SCDHEC

South Carolina Department of Health and Environmental
Control

04-03-C,M,V

KYDES

Kentucky Division of Environmental Services

04-04-C,M,V

GADNR

Georgia Department of Natural Resources

05-01-M

MIDEQ

Michigan Department of Environmental Quality

05-03-C,M,V

WSLH

Wisconsin State Laboratory of Hygiene

06-01-C,M,V,P

TCEQ

Texas Commission on Environmental Quality

08-02-M

IMLAS

IML Air Science Laboratory

09-03-C,V

BAAQMD

Bay Area Air Quality Management District

10-02-C,M,V

ODEQ

Oregon Department of Environmental Quality

11-01-C,M,V;

ERGa

Eastern Research Group

11-02-M

RTI

RTI International

a

VA DCLS

Virginia Division of Consolidated Laboratory Services

a

SCAQMD

South Coast Air Quality Management District

b

CARB

California Air Resources Board

1 Did not participate in the PT program in 2009.
' Cr(VI) not included in the PT program during 2009.

2.3.1 A nalytical Precision Results

Analytical precision was computed from the results of the primary and collocated
samples and their respective replicate analyses extracted from RP records in the AQS database.
This measure of agreement, expressed as the percentage coefficient of variation (% CV), is
defined algebraically in Eq. 1:

%CV = 100

1

X

i=1

(p, -'))
0-5 '(Pr +rt)

2 n

(Eq. 1)

16


-------
where

Pi = the result of the principal analysis on sample z,
rt = the result of the replicate analysis on sample z, and
n = the number of principal-replicate analysis pairs.

The analytical precision for all measurable HAPs analyzed in samples collected in
calendar year 200 is presented in Table 9 with selected analytes summarized graphically in
Figures 8 through 14.

As in previous reporting years, the agreement between replicate analyses of the same
samples is highly variable across sites/laboratories but largely still within the MQO guidelines.
Although only reported for three sites, arsenic agreement is below 2%. Showing marked
improvement since 2008, nearly all laboratories show agreement within the MQO for chromium
(VI). Conversely, agreement between formaldehyde reanalyses is quite variable, albeit
consistently well within the MQO for all sites. Although an MQO is not assigned for PAHs,
naphthalene exhibits agreements below 3% for all reporting sites, well below CVs reported for
VOCs.

2.3.2 Overall Precision Results

Overall precision was computed from the results of the primary, duplicate, and collocated
samples extracted from RD records in the AQS database. This measure of agreement, expressed
as the % CV, is defined algebraically in Eq. 2:

%CV = 100

1

X

1=1

(P, -'))
0-5 • (Pi +rt)

2n

(Eq. 2)

where

Pi = the result of the principal analysis on primary sample z,
rt = the result of the principal analysis on collocated sample z, and
n = the number of primary-collocated sample pairs.

The overall precision results for samples collected in calendar year 2009 are presented in
Table 10 and summarized graphically in Figures 15 through 21. For cases where either the
primary or collocated sample yielded a result of zero, the data pairs were excluded from the
overall precision estimate. All data pairs with reported values were included in the computation.

17


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Table 9. Analytical Precision" for Replicate Analyses of 2009 NATTS Data.

AQS Site Code

Site Description

BENZ

BUTA

CTET

CLFRM

EDB

DCP

EDC

MECL

TCE1122

PERC

TCE

VCM

04-013-9997

Phoenix, AZ

5.1

7.5

9.1

6.2

—

—

—

6.8



5.8

15.1

20.2





(11)

(11)

(11)

(9)







(11)

—

(11)

(2)

(1)

06-065-8001

Rubidoux, CA

	b

—

—

—

—

—

—

—

—

—

—

—

06-085-0005

San Jose, CA

7.2

0

6.2

8.5

—

—

—

9.9



2.8

0







(12)

(2)

(12)

(9)







(9)

—

(11)

(6)

—

08-077-0017

Grand Junction, CO

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0018

Grand Junction, CO

10.3

4.8

5.8

11.4

—

—

—

5.5

—

18.5

4.7

—





(10)

(10)

(10)

(10)







(10)



(10

(6)



11-001-0043

Washington, DC

—

—

—

—

—

—

—

—

—

—

—

—

12-057-3002

Hillsborough County,
FL

—

—

—

—

—

—

—

—

—

—

—

—

12-103-0026

Pinellas County, FL

3.3

13.8

2.9

17.4

27.4

20

9.3

23.5

25.4

11.8

24

31.1





(92)

(92)

(92)

(92)

(44)

(4)

(90)

(92)

(69)

(92)

(73)

(43)

13-089-0002

Decatur, GA

—

—

—

—

—

—

—

—

—

—

—

—

17-031-4201

Northbrook, IL

5.4

13.1

2.7

4.7

—

—

12.8

2.8



9.6

11.3







(5)

(3)

(3)

(3)





(2)

(3)

—

(3)

(3)

—

21-043-0500

Grayson Lake, KY

—

—

—

—

—

—

—

—

—

—

—

—

25-025-0042

Boston, MA

—

—

—

—

—

—

—

—

—

—

—

—

26-163-0033

Dearborn, Ml

6.6

7.2

4.7

5.8

—

—

—

4.2

—

7.3

17

0





(16)

(16)

(16)

(16)







(16)



(16)

(4)

(3)

29-510-0085

St. Louis, MO

5.2

11.6

13.8

9.1

—

—

—

12.3

—

4.9

8.5

20.4





(12)

(12

(12

(12)







(12)



(12)

(6)

(3)

36-005-0110

Bronx, NY

—

—

—

—

—

—

—

—

—

—

—

—

36-055-1007

Rochester, NY

—

—

—

—

—

—

—

—

—

—

—

—

44-007-0022

Providence, Rl

—

—

—

—

—

—

—

—

—

—

—

—

45-025-0001

Chesterfield, SC

—

—

—

—

—

—

—

—

—

—

—

—

49-011-0004

Bountiful, UT

30.9

11.3

13

12.1

—

—

—

14.1



13

54.7







(10)

(9)

(6)

(6)







(6)

—

(6)

(4)

—

50-007-0007

Underhill, VT

—

—

—

—

—

—

—

—

—

—

—

—

51-087-0014

Richmond, VA

—

—

—

—

—

—

—

—

—

—

—

—

53-033-0080

Seattle, WA

6.5

8.5

4.4

10.7

—

—

—

4.1



4.6

6.7







(8)

(8)

(8)

(8)







(8)

—

(8)

(2)

—

55-027-0007

Mayville, Wl

—

—

—

—

—

—

—

—

—

—

—

—



Overall Mean

8.9

11.9

6.4

14.3

27.4



9.3

18.3

25.4

10.7

26.8

29.4





(176)

(163)

(170)

(165)

(44)

20(4)

(92)

(167)

(69)

(169)

(106)

(50)

(continued)


-------
Table 9. Analytical Precision" for Replicate Analyses of 2009 NATTS Data (continued).

AQS Site Code

Site Description

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Ni

CRVI

04-013-9997

Phoenix, AZ

—

—

7.4
(11)

8.9
(3)

b

—

0.5
(13)

0.8
(13)

—

—

—

—

—

—

6

(12)

06-065-8001

Rubidoux, CA

—

—

—

—

4.2

(8)

8.6
(3)

—

—

—

—

—

—

—

—

—

06-085-0005

San Jose, CA

—

—

—

—

—

—

1.3
(10)

0.6
(10)

—

—

—

—

—

—

—

08-077-0017

Grand Junction, CO

—

—

—

—

—

—

—

—

—

—

—

—

—

—

10.8
(6)

08-077-0018

Grand Junction, CO

—

—

13.6
(10)

12.6
(2)

—

—

1.5
(8)

0.9

(8)

—

—

—

—

—

—

—

11-001-0043

Washington, DC

—

—

—

—

—

—

—

—

—

—

—

—

—

—

9.4

(6)

12-057-3002

Hillsborough
County, FL

—

—

—

—

3.2
(66)

7.7
(18)

4.9
(12)

1.5
(12)

—

—

—

—

—

—

12.8
(6)

12-103-0026

Pinellas County, FL

34.1
(46)

36.4
(51)

16.3
(92)

40.3
(89)

—

—

3.4
(12)

4.4

(12)

—

—

—

—

—

—

7.3
(4)

13-089-0002

Decatur, GA

—

—

—

—

2.7
(12)

3.6

(1)

—

—

—

—

—

—

—

—

8.5

(9)

17-031-4201

Northbrook, IL

—

—

10.5
(3)

—

—

—

0.5
(10)

0.4
(10)

1.2
(48)

18.6
(43)

6

(48)

1

(48)

1.1
(48)

4

(48)

10.5
(6)

21-043-0500

Grayson Lake, KY

—

—

—

—

—

—

—

—

—

—

—

—

—

—

7.2
(4)

25-025-0042

Boston, MA

—

—

—

—

—

—

—

—

1.4

(66)

36.6
(52)

9.1
(66)

0.8
(66)

1.1

(66)

1.7
(66)

9.1

(7)

26-163-0033

Dearborn, Ml

—

—

6.7
(16)

—

1.3
(11)

3.7
(11)

0.3
(10)

0.6
(10)

—

—

—

—

—

—

4.2
(12)

29-510-0085

St. Louis, MO

—

—

25.3
(12)

13.9
(6)

—

—

1.5
(14)

1.8
(14)

2

(19)

22.6
(19)

0.7
(19)

1.4
(19)

0.7
(19)

1.8
(19)

6.7
(11)

36-005-0110

Bronx, NY





—

—

—

—

—

—

—

—

—

—

—

—

4.5
(10)

36-055-1007

Rochester, NY





—

—

—

—

—

—

—

—

—

—

—

—

10.2
(2)

(continued)


-------
Table 9. Analytical Precision" for Replicate Analyses of 2009 NATTS Data (continued).

AQS Site Code

Site Description

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Ni

CRVI

44-007-0022

Providence, Rl

—

—

—

—

—

—

—

—

—

—

—

—

—

—

7.2
(4)

45-025-0001

Chesterfield, SC

—

—

—

—

—

—

—

—

—

—

—

—

—

—

15

(6)

49-011-0004

Bountiful, UT

—

—

16.9
(6)

13.9
(2)

—

—

7.6
(10)

3.4
(10)

—

—

—

—

—

—

4.4

(8)

50-007-0007

Underhill, VT

—

—

—

—

—

—

—

—

—

—

—

—

—

—

8.5
(2)

51-087-0014

Richmond, VA

—

—

—

—

—

—

—

—

—

—

—

—

—

—

3.1

(5)

53-033-0080

Seattle, WA

—

—

7.3
(8)

—

2

(11)

3.7
(4)

0.5
(12)

1.3
(12)

—

—

—

—

—

—

4.7

(9)

55-027-0007

Mayville, Wl

—

—

—

—

—

—

—

—

—

—

—

—

—

—

10.6
(4)



Overall Mean

34.1
(46)

36.4
(51)

15.4
(159)

37.9
(102)

3

(108)

6.4
(37)

3.1
(111)

2

(111)

1.4

(133)

28.8
(114)

7.4
(133)

1

(133)

1.1

(133)

2.8
(133)

8.1
(133)

a Expressed as percentage coefficient of variation (%CV) with number of contributing data pairs presented in parentheses. Metals results

are reported at STP at most sites and lcs at others.
b Sample not collected or analyte not reported.
c Across all sites.


-------
Site Name
Bountiful, UT

Dearborn, Ml

Grand Junction, CO

Northbrook, IL

Phoenix, AZ

Pinellas County, FL

San Jose, CA

Seattle, WA

St. Louis, MO

0	10	20	30	40

Percent CV

Figure 8. Analytical Precision Summary for Benzene at NATTS Sample Collection Sites in

2009 (MQO reference indicated at 15%).

CMPDALIAS=BUTA

Site Name
Bountiful, UT

Dearborn, Ml

Grand Junction, CO

Northbrook, IL

Phoenix, AZ

Pinellas County, FL

Seattle, WA

St. Louis, MO

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Percent CV

Figure 9. Analytical Precision Summary for 1,3-Butadiene at NATTS Sample Collection

Sites in 2009.

21


-------
Site Name
Bountiful, UT

Dearborn, Ml

Grand Junction, CO

Nortlibrook, IL

Phoenix, AZ

Pinellas County, FL

Seattle, WA

St. Louis, MO

0	10	20	30

Percent CV

Figure 10. Analytical Precision Summary for Acrolein at NATTS Sample Collection Sites

in 2009 (MQO reference indicated at 15%).

CMPDALIAS= FORM

Site Name
Bountiful, UT

Dearborn, Ml

Grand Junction, CO

Hillsborough County, FL

Northbrook, IL

Phoenix, AZ

Pinellas County, FL

San Jose, CA

Seattle, WA

St. Louis, MO

012345678

Percent CV

Figure 11. Analytical Precision Summary for Formaldehyde at NATTS Sample Collection

Sites in 2009.

22


-------
CM PDALIAS = N APH

Site Name
Dearborn, Ml

Decatur, GA

Hillsborough County, FL
Rubidoux, CA
Seattle, WA

2	3

Percent CV

Figure 12. Analytical Precision Summary for Naphthalene at NATTS Sample Collection

Sites in 2009.

CMPDALIAS=CRVI

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Grand Junction, CO
Grayson Lake, KY
Hillsborough County, FL
Mayville, Wl
Norlhbrook, IL
Phoenix, AZ
Pinellas County, FL
Providence, Rl
Richmond, VA
Rochester, NY
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

8 9 10 11 12 13 14 15 16

Percent CV

Figure 13. Analytical Precision Summary for Chromium (VI) at NATTS Sample Collection

Sites in 2009 (MQO reference indicated at 15%).

23


-------
CMPDALIAS = AS

Site Name
Boston, MA

Northbrook, IL

St. Louis, MO

0	12	3

Percent CV

Figure 14. Analytical Precision Summary for Arsenic at NATTS Sample Collection Sites in

200 .

Examination of Figures 15 through 21 reveals that aggregate precision associated with
sample collection and analysis varies widely by collection site and analyte. Not unexpectedly,
the aggregate variability observed is substantially greater than the analytical variability shown in
Figures 8 through 14. Variability seen for many sites may reflect the presence of extreme values.
No attempt has been made to elucidate this cause through careful review of the individual data
pairs for each analyte and site. With the exception of acrolein where only one site achieved the
MQO in 2009, some sites achieve the MQOs, and some sites do not for most analytes,
suggesting that the 15% threshold is a reasonable target for the MQO. The fact that many sites
exhibit percentage CVs above the MQO target level suggests that the collection methodology
contributes significantly to the overall variability in the data for a given site and analyte. Without
identifying specific sites, the percentages of reporting sites with percentage CV above the MQO
threshold are 46%, 35%, 30%, 55%, 91%, and 36% for arsenic, chromium (VI), benzene, 1,3-
butadiene, acrolein, and formaldehyde, respectively. These percentages are consistent with
variations in collection and analysis challenges posed by different analytes, with more
problematic analytes (e.g., butadiene, and acrolein) showing poorer attainment of the MQO. That
fact not withstanding, the percentage CVs computed across sites by analyte are somewhat
misleading because they may be influenced by atypically large CVs at selected sites. The QA
report of the NATTS stations for 2006 [4] warned of the danger of extracting duplicate and
collocated results using only the RP records. For that reason—and despite the considerable
difficulty in determining the specific primary, duplicate, and collocated POCs for each site—the
data presented here are based primarily on the RD records. The two exceptions were the
duplicate data for VOCs from the Washington, DC and Pinellas County, FL sites that were
uploaded to AQS only as RP records and were, therefore, extracted as such.

24


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009.

AQS Site ID

Site Description

Duplicate
Type

BENZ

BUTA

CTET

CLFRM

EDB

DCP

EDC

MECL

TCE1122

PERC

TCE

VCM

04-013-9997

Phoenix, AZ

Collocate

14.7

U)

9.2

U)

14.4

(7)

6.8

(6)

	b

—

—

50.7

U)

—

9.9

U)

6.1

(1)

—

04-013-9997

Phoenix, AZ

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

06-037-1103

Los Angeles, CA

Collocate

10.8
(27)

24.5
(28)

"

23.4
(28)

"

"

"

27
(28)

"

28.7
(25

26
(26)

"

06-037-1103

Los Angeles, CA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

06-065-8001

Rubidoux, CA

Collocate

19
(23)

25.5
(24)

—

23.7
(24)

	

—

—

62.6
(2)

—

41.7
(23)

0

(3)

—

06-065-8001

Rubidoux, CA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

06-085-0005

San Jose, CA

Collocate

13
(25)

60
(4)

—

55.6
(20)

	

—

—

48.8
(22)

—

44.6
(25)

37.9
(11)

—

06-085-0005

San Jose, CA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0017

Grand Junction, CO

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0017

Grand Junction, CO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0018

Grand Junction, CO

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0018

Grand Junction, CO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

11-001-0043

Washington, DC

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

11-001-0043

Washington, DC

Duplicate

7.4
(59)

23.9
(58)

6.9
(59)

6

(59)

0

(6)

15.7
(27)

17.6
(59)

12.5
(47)

10.8
(19)

6.8
(59)

0

(41)

13.1
(13)

12-057-3002

Hillsborough
County, FL

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

12-057-3002

Hillsborough
County, FL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

12-103-0026

Pinellas County, FL

Collocate

3.7
(31)

14.7
(31)

5

(31)

26.2
(31)

36.1
(12)

28.3

(1)

11.3
(30)

36.7
(31)

30.4
(22)

14.9
(31)

34.2
(25)

43.1
(14)

12-103-0026

Pinellas County, FL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

13-089-0002

Decatur, GA

Collocate

24.2
(60)

—

9.5
(21)

15

(9)

—

—

0

(1)

88.7

(1)

—

21.9
(4)

0

(1)

—

13-089-0002

Decatur, GA

Duplicate





—

—

—

—

—

—

—

—

—

—

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

BENZ

BUTA

CTET

CLFRM

EDB

DCP

EDC

MECL

TCE1122

PERC

TCE

VCM

17-031-4201

Northbrook, IL

Collocate

25.8

	

9.1

23.6

	

	

0

107

	

34.4

31.4

	







(1)



(1)

(1)





(1)

(1)



(1)

(1)



17-031-4201

Northbrook, IL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

21-043-0500

Grayson Lake, KY

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

21-043-0500

Grayson Lake, KY

Duplicate

4.7

—

—

—

—

—

—

44.7

—

—

—

—







(4)













(11)









25-025-0042

Boston, MA

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

25-025-0042

Boston, MA

Duplicate

4.8

27.3

3.2

3.6

23.6

11.2

4.3

19.3

26.2

5.1

9.7

4.5







(31)

(31)

(31)

(31)

(4)

(23

(31)

(31)

(10)

(31)

(30)

(20)

26-163-0033

Dearborn, Ml

Collocate

9.3

10.5

3.8

39.4

—

—

—

10.1

—

6.9

15.5

0







(8)

(8)

(8)

(8)







(8)



(8)

(2)

(1)

26-163-0033

Dearborn, Ml

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

29-510-0085

St. Louis, MO

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

29-510-0085

St. Louis, MO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

36-005-0110

Bronx, NY

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

36-005-0110

Bronx, NY

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

36-055-1007

Rochester, NY

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

36-055-1007

Rochester, NY

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

41-051-0246

Portland, OR

Collocate

33.3

5.9

8.9

19.6

	

0(2)

	

38.6

	

19.6

	

	







(23)

(3)

(22)

(3)





(39)



(8)





41-051-0246

Portland, OR

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

41-061-0119

La Grande, OR

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

41-061-0119

La Grande, OR

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

44-007-0022

Providence, Rl

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

44-007-0022

Providence, Rl

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

45-025-0001

Chesterfield, SC

Collocate

36.4

—

0

—

—

—

—

31.3

—

—

—

—







(12)



(11)









(24)









45-025-0001

Chesterfield, SC

Duplicate





—

—

—

—

—

—

—

—

—

—

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

BENZ

BUTA

CTET

CLFRM

EDB

DCP

EDC

MECL

TCE1122

PERC

TCE

VCM

48-201-1039

Deer Park, TX

Collocate

11.6
(55)

26
(16)

7

(55)

12.5
(53)

23.6
(4)

34.6
(5)

17.3
(29)

10.7
(51)

21.1

(5)

15.7
(42)

28.3
(20)

15.8
(20)

48-201-1039

Deer Park, TX

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

48-203-0002

Harrison County,
TX

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

48-203-0002

Harrison County,
TX

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

49-011-0004

Bountiful, UT

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

49-011-0004

Bountiful, UT

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

50-007-0007

Underhill, VT

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

50-007-0007

Underhill, VT

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

51-087-0014

Richmond, VA

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

51-087-0014

Richmond, VA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

53-033-0080

Seattle, WA

Collocate

9.8
(4)

4.5
(4)

5.3
(4)

32.6
(4)

—

—

—

40.5
(4)

—

5.2
(4)

9.4

(1)

—

53-033-0080

Seattle, WA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

55-027-0007

Mayville, Wl

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

55-027-0007

Mayville, Wl

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—



Overall Mean

All Dups.

18.3
(311)

23.9
(156)

6.9
(191)

25.5
(218)

31.7
(20)

17.7
(31)

11.9

(92)

36.4
(282)

28.2
(37)

25.5
(209)

26.2
(121)

23.9
(55)

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Nl

CRVI

04-013-9997

Phoenix, AZ

Collocate

—

—

20.7

U)

118

(1)

—

—

4.2

(6)

5.8
(6)













15.1
(6)

04-013-9997

Phoenix, AZ

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

06-037-1103

Los Angeles, CA

Collocate

—

—

89.9
(28)

—

—

—

36
(26)

31.2
(26)













15.1
(6)

06-037-1103

Los Angeles, CA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

06-065-8001

Rubidoux, CA

Collocate

—

—

85.9
(24)

—

—

—

24.4
(29)

28.2
(29)













15.1
(6)

06-065-8001

Rubidoux, CA

Duplicate

—

—

—

—

17.2
(3)

27

(1)



















06-085-0005

San Jose, CA

Collocate

—

—

42.9
(24)

—

—

—

24.1
(30)

26.7
(30)













15.1
(6)

06-085-0005

San Jose, CA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0017

Grand Junction,
CO

Collocate

—

—

—

—

—

—

—

—

—

4.7

(6)

5.1

(6)

29.4
(34

7.1
(92)

37.1
(46)

34.3
(3)

08-077-0017

Grand Junction,
CO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0018

Grand Junction,
CO

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

08-077-0018

Grand Junction,
CO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

11-001-0043

Washington, DC

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

8

(3)

11-001-0043

Washington, DC

Duplicate

0

(3)

0

(3)

26.1
(50)

37.2
(49)























12-057-3002

Hillsborough
County, FL

Collocate

—

—

—

—

20.8
(33)

39.6
(8)

—

—

15.2
(59)

0

(59)

22.3
(59)

16.1
(59)

12.8
(59)

12
(59)

20.7
(3)

12-057-3002

Hillsborough
County, FL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Nl

CRVI

12-103-0026

Pinellas County, FL

Collocate

34.3
(16)

35.2
(17)

24.7
(31)

69.1
(29)





















7.5
(2)

12-103-0026

Pinellas County, FL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

13-089-0002

Decatur, GA

Collocate

—

—

—

—

11.8

(5)

—

41.5
(24)

14.3
(22)

18.3
(16)

84.9

(1)

22
(24)

27.2
(25)

24.6
(25)

15.2
(25)

14.1
(4)

13-089-0002

Decatur, GA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

17-031-4201

Northbrook, IL

Collocate

—

—

3.7

(1)

—

—

—

4.9

(5)

2.5
(5)

17.3
(23)

43.9
(20)

24
(23)

19
(23)

10.7
(23)

23.8
(23)

35
(3)

17-031-4201

Northbrook, IL

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

21-043-0500

Grayson Lake, KY

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

9.4

(2)

21-043-0500

Grayson Lake, KY

Duplicate

—

—

—

—

—

—

15.4
(27)

15.2
(27)

6.6
(26)

—

—

6.8
(56)

45.7
(50)

44.9
(3)

—

25-025-0042

Boston, MA

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

25-025-0042

Boston, MA

Duplicate

0

(2)

47.1

(1)

19.1
(31)

58.5
(27)

—

—

7.5
(31)

28.5
(31)

3

(33)

45.3
(25)

27.9
(33)

5.9
(33)

5.9
(33)

8.7
(33)

10.8
(3)

26-163-0033

Dearborn, Ml

Collocate

—

—

26.9
(8)

—

5.3

(5)

13.8
(5)

5.3

(5)

3.8

(5)

12.3
(56)

21
(48)

15
(54)

10.8
(112)

7.8
(56)

24.3
(55)

8.9

(6)

26-163-0033

Dearborn, Ml

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

29-510-0085

St. Louis, MO

Collocate

—

—

—

—

—

—

—

—

4.7
(11)

21.5
(11)

20.9
(11)

9.1
(11)

7.4
(11)

17.6
(11)

11.4

(6)

29-510-0085

St. Louis, MO

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

36-005-0110

Bronx, NY

Collocate

—

—

—

—

—

—

—

—

7.4
(51)

15.8
(51)

37.4
(49)

4.1

(51)

3.7
(51)

7.3
(51)

7.6
(5)

36-005-0110

Bronx, NY

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

36-055-1007

Rochester, NY

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

36-055-1007

Rochester, NY

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

41-051-0246

Portland, OR

Collocate

—

—

—

—

21.8
(44)

12.3
(12)

7

(47)

6.7
(47)

8.6
(40)

17.4
(40)

17.7
(40)

8.4
(40)

8.7
(40)

8.1
(40)

—

41-051-0246

Portland, OR

Duplicate









—





—

—

—

—

—

—

—

—

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Nl

CRVI

41-061-0119

La Grande, OR

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

41-061-0119

La Grande, OR

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

44-007-0022

Providence, Rl

Collocate

—

—

—

—

—

—

10.6
(24)

15.5
(24)

25.6
(24)

34.1
(16)

55.4
(12)

15.2
(26)

11.8
(26)

16.4
(26)

10.1

(1)

44-007-0022

Providence, Rl

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

45-025-0001

Chesterfield, SC

Collocate

—

—

—

—

—

—

10.4
(61)

12.7
(60)

25.8
(48)

—

45.7
(60)

39.1
(70)

14.4
(96)

66.6
(72)

—

45-025-0001

Chesterfield, SC

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

26.5
(3)

48-201-1039

Deer Park, TX

Collocate

23.6
(4)

33.3
(2)

102
(53)

—

37.4
(56

36.1
(30)

















33.1
(23)

48-201-1039

Deer Park, TX

Duplicate

—

—

—

—

11.1
(56

35.1
(49)



















48-203-0002

Harrison County,
TX

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

48-203-0002

Harrison County,
TX

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

49-011-0004

Bountiful, UT

Collocate

—

—

—

—

—

—

—

—

27.4
(2)

—

0

(1)

7.2
(3)

14.5
(3)

69.9

(1)

41.9
(4)

49-011-0004

Bountiful, UT

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

50-007-0007

Underhill, VT

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

50-007-0007

Underhill, VT

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

7.5

(1)

51-087-0014

Richmond, VA

Collocate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

6.7
(2)

51-087-0014

Richmond, VA

Duplicate

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

53-033-0080

Seattle, WA

Collocate

—

—

28.7
(4)

—

—

—

5.7
(6)

2.7
(6)















53-033-0080

Seattle, WA

Duplicate

—

—

—

—

13.2
(6)

5

(2)

















16.8
(4)

(continued)


-------
Table 10. Overall Precision" for Primary and Collocated Samples from 2009 (continued).

AQS Site ID

Site Description

Duplicate
Type

cDCPEN

tDCPEN

ACRO

ACRY

NAPH

BaP

FORM

ACET

AS

BE

CD

PB

MN

Nl

CRVI

55-027-0007

Mayville, Wl

Collocate

—

—

—

—

—

—

—

—

12.5
(2)

—

2.6

(1)

35.5

(1)

21.7

(1)

12.8
(2)

7.5
(2)

55-027-0007

Mayville, Wl

Duplicate

—

—

—

—

—

—

3.8

(5)

4.5

(5)

















Overall Mean

All Dups.

31
(22)

35.7
(20)

70.1
(211)

65.5
(57)

24.3
(208)

32.9
(107)

20
(326)

19.6
(323)

15.3
(391
)

24.6
(277
)

30.2
(373
)

19.5
(544)

17.6
(546)

32.5
(447)

24.2
(83)

a Expressed as percentage coefficient of variation (%CV) with number of contributing data pairs presented in parentheses. Metals results are reported at STP at most sites and local conditions at others.
b Sample either not collected or analyte not reported.
c Across all sites.


-------
Site Name
Boston, MA
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grayson Lake, KY
Los Angeles, CA
Northbrook, IL
Phoenix, AZ
Pinellas County, FL
Portland, OR
Rubidoux, CA
San Jose, CA
Seattle, WA
Washington, DC

0	10	20	30	40

Percent CV

Figure 15. Overall Precision Summary for Benzene at NATTS Sample Collection Sites in

200 (MQO reference indicated at 15%).

CMPDALIAS=BUTA

Site Name
Boston, MA

Dearborn, Ml

Deer Park, TX

Los Angeles, CA

Phoenix, AZ

Pinellas County, FL

Portland, OR

Rubidoux, CA

San Jose, CA

Seattle, WA

Washington, DC

0	10	20	30	40	50	60	70

Percent CV

Figure 16. Overall Precision Summary for 1,3-Butadiene at NATTS Sample Collection
Sites in 2009 (MQO reference indicated at 15%).

32


-------
Site Name
Boston, MA

Dearborn, Ml

Deer Park, TX

Los Angeles, CA

Northbrook, IL

Phoenix, AZ

Pinellas Counly, FL

Rubldoux, CA

San Jose, CA

Seattle, WA

Washington, DC

0 10 20 30 40 50 60 70 80 90 100 110

Percent CV

Figure 17. Overall Precision Summary for Acrolein at NATTS Sample Collection Sites in

2009 (MQO reference indicated at 15%).

Site Name
Boston, MA
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Grayson Lake, KY
Los Angeles, CA
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Portland, OR
Providence, Rl
Rubidoux, CA
San Jose, CA
Seattle, WA

0	10	20	30	40	50

Percent CV

Figure 18. Overall Precision Summary for Formaldehyde at NATTS Sample Collection
Sites in 2009 (MQO reference indicated at 15%).

33


-------
Site Name

Dearborn, Ml

Decatur, GA

Deer Park, TX

Hillsborough County, FL

Portland, OR

Rubidoux, CA

Seattle, WA

0	10	20	30

Percent CV

Figure 19. Overall Precision Summary for Naphthalene at NATTS Sample Collection Sites

in 2009 (MQO reference indicated at 15%).

CMPDALIAS=CRVI

Site Name
Boston, MA
Bountiful, UT
Bronx, NY
Chesterfield, SC
Dearborn, Ml
Decatur, GA
Deer Park, TX
Grand Junction, CO
Grayson Lake, KY
Hillsborough County, FL
Mayville, Wl
Norttibrook, IL
Phoenix, AZ
Pinellas County, FL
Providence, Rl
Richmond, VA
Seattle, WA
St. Louis, MO
Underhill, VT
Washington, DC

Percent CV

Figure 20. Overall Precision Summary for Chromium (VI) at NATTS Sample Collection
Sites in 200 (MQO reference indicated at 15%).

34


-------
CMPDALIAS = AS

Site Name
Boston, MA

Bountiful, UT"

Bronx, NY

Chesterfield, SC

Dearborn, Ml

Decatur, GA

Grayson Lake, KY

Hillsborough County, FL

Mayville, Wl

Northbrook, IL

Portland, OR

Providence, Rl

St. Louis, MO

10

20

30

Percent CV

Figure 21. Overall Precision Summary for Arsenic at NATTS Sample Collection Sites in

2009 (MQO reference indicated at 15%).

2.4 Laboratory Bias Data Based on Proficiency Testing Samples

PT audits of participating NATTS sample analysis laboratories were conducted
semiannually for VOCs and carbonyls and annually for metals and PAHs in 2009. Alion Science,
Inc., under contract to EPA (Contract No. 68-D03-006), generated "spiked" samples containing
known amounts of the HAPs of interest and delivered these spiked samples to each laboratory in
2009 for each of the VOC, carbonyl, and metals analyte groups. Following chemical analyses,
the participating laboratories returned their results to Alion, which, in turn, prepared reports
comparing the laboratory-measured values to the stated (known) values for each proficiency
testing sample. The results of these PT sample analyses were provided to RTI International by
EPA for calendar year 2009.

Laboratory bias is defined as the percentage difference between the laboratory's
measured value and the known value for the audit sample:

„, ^ ..	Measured - Known	

%Difference =	100

Known

(Eq. 3)

Tables 11 through 13 present the results of the PT samples for all compounds analyzed.
To reflect overall bias independent of direction, the mean of the absolute value of the bias, along
with the minimum and maximum bias values, is presented in the bottom and right-hand
summaries for the individual tabulated values. Figure 22 shows boxplots summarizing laboratory
bias results for all the participating laboratories across the five compounds for which PT data

35


-------
Table 11. Performance Testing Bias Results" for VOCs in 2009 NATTS Laboratories.

Laboratory
Code

Lab Description

BENZ

BUTA

CTET

CLFR

M

EDB

DCP

EDC

MECL

TCE1
122

PERC

TCE

VCM

c-
CPEN

t-
CPEN

ACRO

Mean
Abs. Bias
(across
anaiylesf

Min.

Max.

01-01-V

Rl Dept. of Health
Laboratories

0.41

-11.9

-9.21

-3.43

-9.36

-8.72

-11.7

-10.7

1.79

-9.66

-13.7

-10.3

-12.1

-12.4

87.9

15.3

-21.0

186.22

02-01-C

NYS DEC BAQS

-0.77

-12.2

0.26

-15.4

-11.4

-11.3

-11.6

-6.86

1.55

-9.62

-15.9

-9.83

-17.2

-13.4

-6.09

10.6

-24.8

7.00

03-01-V

Maryland

Department of the
Environment

5.98

2.26

4.61

6.00

-8.32

-2.28

-1.90

10.7

-2.56

6.82

-3.04

12.8

-12.3

-9.17

3.41

6.97

-15.9

13.4

03-02-V

Virginia Division of
Consolidated
Laboratory Services

-21.2

-16.6

-17.6

-29.0

-0.19

-7.84

-24.1

-23.0

-4.26

-6.50

-9.36

-20.6

-14.5

-3.80

14.2

18.8

-32.5

51.9

04-01-V

Pinellas County
DEM AQ

-9.12

-6.76

-9.57

-13.1

-5.95

-12.4

-13.4

-15.5

-6.91

-11.3

-10.3

-5.84

-7.86

-8.08

-0.71

10.5

-27.6

14.1

04-02-V

SC Dept of HEC,
Div. of AQ Analysis

-24.3

19.7

-34.5

-27.9

16.8

-8.37

-7.23

-10.3

97.5

-5.96

-8.62

-20.7

-25.6

9.88

67.1

26.8

-38.0

112

04-03-V

KY Div. of

Environmental

Services

-3.08

-5.83

-4.87

-4.06

-2.18

-11.7

-7.56

-4.88

-1.99

-1.10

-3.28

1.75

-4.53

-4.61

11.3

6.80

-16.9

15.2

04-04-V

GA DNR EPD
Laboratory

-15.3

-17.8

-12.3

-17.5

-11.8

-15.7

-13.5

-12.4

-19.8

-15.9

-12.1

-8.55

-15.8

-13.7

3.15

14.3

-21.7

15.6

05-01-V

Ml DEQ Lab

-9.51

8.89

-2.22

-9.37

-6.76

-11.2

-12.2

-13.0

-0.76

-3.05

-3.22

11.7

-12.7

-3.60



10.3

-24.4

20.9

05-03-V

Wisconsin DNR

-12.2

-12.8

10.9

-19.3

-24.0

-2.37

-14.8

10.3

-25.6

-18.2

-9.47

-1.28

-21.0

-12.2

27.3

15.3

-29.5

34.3

06-01-V

Texas CEQ

-3.44

-1.44

4.35

-17.9

-17.9

-28.0

-20.3

-15.1

-1.27

-21.9

-13.4

-3.91

2.78

3.80

6.67

12.2

-30.5

14.8

09-03-V

Bay Area Air Quality

Management

District

-10.2

-23.1

0.56

-9.69

-4.06

C

-17.2

-21.0

"

-9.58

4.09

-5.32

"

"

117

21.5

-32.2

152

09-06-C

San Diego County
Air Pollution Control
District

-10.9

-9.62

-6.14

-14.4

-3.29

-14.9

-9.29

-10.3

-7.40

-8.64

-9.74

-10.8

-3.39

6.25

1.03

8.95

-25.6

13.2

10-02-V

Oregon DEQ Lab

-31.8

-10.9

-45.9

-26.7

-41.6

-30.2

-24.2

14.0

-45.2

-43.

-36.8

1.03

-35.4

-42.5

-

33.4

-61.6

29.7

11-01-V

ERG

6.16

-0.52

1.85

5.44

-1.50

-2.22

2.69

5.66

-7.25

1.11

2.71

-0.06

1.63

-4.02

-14.7

4.66

-18.5

10.4



Mean Abs. Bias
(across laboratories)

11.8

15.3

12.7

14.9

11.8

12.9

12.8

12.4

16.4

14.0

12.6

9.67

13.3

12.5

30.3

14.1







Minimum

-35.3

-42.9

-52.8

-30.3

-45.8

-33.7

-32.5

-32.2

-61.6

-32.5

-40.3

-26.8

-40.2

-50.5

-23.6









Maximum

12.0

21.1

20.0

7.45

16.8

5.26

3.42

29.7

112

3.42

14.6

20.9

11.0

14.8

186







a Computed as the mean of the individual percent differences.
b Computed as the mean of the absolute values of the individual percent differences.
c Analyte not reported.


-------
Table 12. Proficiency Testing Bias Results" for Carbonyls in 2009 NATTS Laboratories.

Laboratory
Code

Laboratory Description

FORM

ACET

Mean Abs. Bias
(across
anaiylesf

Min.

Max.

01-01-C

Rl Dept. of Health Laboratories

-5.30

-1.15

9.22

-14.3

12.0

01-02-C

Vermont DEC Environmental Lab

-23.7

-25.6

24.7

-36.3

-11.1

01-03-C

MADEP

-9.56

-10.9

10.2

-15.4

-6.40

02-01-C

NYSDEC BAQS

-13.4

-15.4

14.4

-22.9

-8.00



Philadelphia Air Management Services

-6.83

-9.37

8.10

-13.1

-5.60

03-01-C

Laboratory











03-02-C

Virginia Division of Consolidated Laboratory

-6.54

-11.0

8.79

-14.9

-6.22



Services











04-02-C

SC Dept of HEC, Div. of AQ Analysis

1.62

-7.95

4.83

-14.3

2.67

04-03-C

KY Div. of Environmental Services

-13.7

-20.0

16.8

-40.0

0.00

04-04-C

GADNR,EPD Laboratory

-7.78

-22.1

14.9

-25.7

-3.56

05-01-C

Ml DEQ Lab

-2.73

-8.00

5.37

-12.0

-0.57

05-03-C

Wisconsin DNR

-5.40

-9.15

10.3

-14.3

-2.22

06-01-C

Texas CEQ

-12.4

-17.4

14.9

-21.1

-11.6

09-03-C

Bay Area Air Quality Management District

-7.84

0.06

4.75

-11.1

1.71

09-06-C

San Diego County Air Pollution Control District

-2.74

-6.94

4.84

-13.7

-0.16

09-08-C

South Coast Air Quality Management District

-15.7

-14.2

15.0

-21.1

-10.2

10-02-C

Oregon DEQ Lab

-10.8

-14.3

12.5

-20.6

-8.00

11-01-C

ERG

-7.81

-10.1

8.93

-17.7

-2.40



Mean Abs.Bias (across laboratories)

9.66

12.7

11.2







Minimum

-36.3

-40.0









Maximum

2.67

12.0







a Computed as the mean of the individual percent differences.
b Computed as the mean of the absolute values of the individual percent differences.

were compiled: 1,3-butadiene, formaldehyde, acrolein, benzene, and arsenic. In this figure, the
bottom and top of the "box" represent the 25th and 75th percentiles, respectively; the horizontal
line inside the box represents the median value; the diamond symbol represents the mean; the top
and bottom "whiskers" extend to a length of 1.5 times the interquartile range (IQR). The IQR is
defined as the distance between the 25* and 75th percentiles of the distribution of values. The
reference line in this figure represents the MQO bias goal of 25%. To maintain figure clarity,
only labs whose results fell outside of a window defined by 1.5 x IQR are identified on the
graphical display. Selected results that fell outside of the IQR are identified by their laboratory
ID number assigned by Alion; a cross-reference between the NATTS site and assigned
laboratory codes is provided above in Tables 7 and 8. A laboratory's results were included in the
summary analysis only if the laboratory provided analysis of a particular sample type. Although
some individual laboratories report PT sample concentrations that exhibit bias beyond the
NATTS MQO, the profound majority of laboratories demonstrate laboratory biases for benzene,
1,3-butadiene, formaldehyde, and arsenic that are well within the MQO limit of ฑ25%. The
biases for benzene, 1,3-butadiene, and formaldehyde are slightly negative, implying a smaller
measured result than expected; biases for acrolein and arsenic are nominally positive. Percentage
participation in the PT program (Table 14) was 100% for all compound classes.

37


-------
Table 13. Proficiency Testing Bias" Results for Metals in 2009 NATTS Laboratories.

















Mean Abs.





















Bias





Laboratory
Code

Lab
Description

AS

BE

CD

PB

MN

Nl

(across
analytesf

Min.

Max.

01-01-M

Rl Dept. of

Health

Laboratories

-24.4

-8.46

-21.5

-36.3

-41.2

-32.9

27.5

-41.2

-8.46

03-01-M

WVDEP
Division of Air
Quality

23.7

41.6

27.7

182

3.690

25.7

50.7

3.69

182

03-02-C

Virginia Division
of Consolidated
Laboratory
Services

25.6

37.8

27.2

156

-5.30

35.6

48.0

-5.30

156

04-01 -M

Environmental
Protection
Comm. of
Hillsborough
Co.

12.5

37.3

24.1

-3.79

4.84

12.9

15.9

-3.79

37.3

04-02- M

SC Dept of
HEC, Div. of AQ
Analysis

3.95

9.67

-0.55

-5.15

0.81

-9.29

4.90

-9.29

9.67

04-03-M

KY Div. of

Environmental

Services

12.0

32.0

17.2

-6.23

-4.84

4.86

12.8

-6.23

32.0

04-04-M

GA DNREPD
Laboratory

-0.34

2.94

-6.93

32.4

-27.8

-13.9

14.0

-27.8

32.4

05-01-M

Ml DEQ Lab

-22.7

-11.9

-17.9

-32.3

-11.3

-18.6

19.1

-32.3

-11.3

05-03-M

Wisconsin DNR

-3.40

10.5

9.12

-14.1

-28.3

-13.1

13.2

-28.3

10.5

06-01-M

Texas CEQ

4.81

10.6

6.57

-15.8

-26.2

-6.21

11.7

-26.2

10.6

08-02-M

IML Air Science

2.75

19.9

6.57

0.00

-0.23

-8.00

6.24

-8.00

19.9

09-08- M

South Coast Air
Quality
Management
District

-28.2

-47.7

-19.9

-29.7

-44.0

-40.4

35.0

-47.7

-19.9

10-02-M

Oregon DEQ
Lab

-12.5

-7.08

-8.94

-32.9

-41.9

-32.9

22.7

-41.9

-7.08

11-01-M

ERG

-14.8

-5.53

-16.2

-30.6

-37.7

-28.9

22. 3

-37.7

-5.53

11-02-M

RTI

International

-1.37

3.45

-4.74

-24.5

-34.8

-29.3

16.4

-34.8

3.45



Mean Abs.Bias

13.5

20.4

15.1

37.6

20.0

20.4

21.2







(across
laboratories)





















Minimum

-28.2

-47.7

-21.5

-36.3

-44.0

-40.4









Maximum

25.6

41.6

27.7

181

7.83

35.6







a Computed as the mean of the individual percent differences.
b Computed as the mean of the absolute values of the individual percent differences.

38


-------
Distribution of PERCDIFF by CMPDALIAS

P-1

g
a

BUTA

1	r

FORM	ACRO

BENZ

T

AS

Analyte

Figure 22. Distribution of Laboratory Bias by Analyte for Proficiency Testing Data from

200 .

Participation in the laboratory PT program during 200 by all NATTS-affiliated
laboratories is shown in Table 14. All participating laboratories completed the PT sample
analyses.

Table 14. Proficiency Testing Program Participation for 2009.



Percentage

Compound Class

Participation

Carbonyls

100

Metals

100

VOCs

100

2.5 Flow Audit Results from Instrument Performance Audits

Six NATTS field sites (Dearborn, MI; Deer Park, TX; Harrison County, TX; Mayville,
WI; Northbrook, IL; St. Louis MO) were audited during calendar year 200 for canister,
carbonyl, PMio, chromium (VI), and PAH samplers. The IPA involves independent
measurements of flow rates on all resident sampler types at the NATTS site using certified flow,
temperature, and pressure instruments.

39


-------
Sampler flows were measured using a calibrated volumetric flow measurement device
with flow rates subsequently corrected to the standard conditions of 25 EC and 1 atm.
Comparison of the site-recorded and similarly corrected flow rate to the audited flow rate
afforded calculation of field bias. For this purpose, field bias is defined as the percentage
difference between the corrected site flow (Fsc) and the corrected audit flow (Fac):

Fv — Fa

%Difference = —		— • 100	(Eq. 4)

Fac

The results from the flow audits conducted at six sites during calendar year 2009, along
with the relevant sampling techniques, are shown in Table 15. The specific sampler audited (i.e.,
primary or collocated) is identified in column 3, with no audits performed on canister samplers.
If present during the audit, collocated samplers were also audited. Because canister and carbonyl
samplers may have multiple flow channels to facilitate duplicate sampling, all active channels
were also subjected to a flow audit. PMi0 samplers have only primary channels.

Table 15. Flow Audit Results from 2009 Instrument Performance Audits.

Site Identifier

Method

Sampler

Channel

Measurements

Percentage
Difference



Canister3

Primary

NA

Not performed0





Carbonylb

Primary

1

Site: 0.7412 L/min (actual)
Auditd: 0.7488 L/min (actual)

-1.0



Carbonyl

Duplicate/Collocated

2

Site: 0.7500 L/min (actual)
Audit: 0.7635 L/min (actual)

-1.8



PMioe

Primary

NA

Site: 41.66 ft3/min (STP)
Audit: 40.63 ft3/min (STP)

2.5

Dearborn, Ml

PMioe

Duplicate/Collocated

NA

Site: 40.71 ft3/min (STP)
Audit: 39.23 ft3/min (STP)

3.8



Cr(VI)

Primary

NA

Site: 14.4 L/min (actual)
Audit: 13.58 L/min (actual)

6.0



Cr(VI)

Duplicate/Collocated

NA

Site: 14.7 L/min (actual)
Audit: 13.8 L/min (actual)

6.6



PAH

Primary

NA

Site: 6.91 ft3/min (STP)
Audit: 7.25 ft3/min (STP)

-4.7



PAH

Duplicate/Collocated

NA

Site: 7.30 ft3/min (STP)
Audit: 7.32 ft3/min (STP)

-0.3



Canister3

Primary

NA

Not performed





Carbonylb

Primary

1

Site: 1.125 L/min (actual)
Audit: 1.09 L/min (actual)

3.2

Deer Park, TX

Carbonyl

Duplicate/Collocated

2

Site: 1.134 L/min (actual)
Audit: 1.08 L/min (actual)

5.0



PMioe

Primary

NA

Site: 40.29 ft3/min (STP)
Audit: 40.29 ft3/min (STP)

0.0



PM10

Duplicate/Collocated

NA

Site: 40.29 ft3/min (STP)
Audit: 40.41 ft3/min (STP)

-0.3

(continued)

40


-------
Table 15. Flow Audit Results from 2009 Instrument Performance Audits (continued).

Site Identifier

Method

Sampler

Channel

Measurements

Percentage
Difference



Cr(VI)

Primary

NA

Site: 11.51 L/min (actual)
Audit: 11.58 L/min (actual)

-0.6

Deer Park, TX

Cr(VI)

Duplicate/Collocated

NA

Site: 11.51 L/min (actual)
Audit: 11.58 L/min (actual)

-0.6

(continued)

PAH

Primary

NA

Site: 9.83 ft3/min (STP)
Audit: 9.84 ft3/min (STP)

-0.1



PAH

Duplicate/Collocated

NA

Site: 8.3 ft3/min (STP)
Audit: 8.4 ft3/min (STP)

-1.2



Canister3

Primary

NA

Not performed





Carbonylb

Primary

1

Site: 1.099 L/min (actual)
Auditl: 1.109 L/min (actual)

-0.9

Harrison County,
TX

Carbonyl

PM10e

Duplicate/Collocated
Primary

2

NA

Site: 1.107 L/min (actual)
Audit: 1.112 L/min (actual)

Site: 39.98 ft3/min (STP)
Audit: 39.96 ft3/min (STP)

o o



Cr(VI)

Primary

NA

Site: 11.86 L/min (actual)
Audit: 12.13 L/min (actual)

-2.2



PAH

Primary

NA

Site: 8.57 ft3/min (STP)
Audit: 8.49 ft3/min (STP)

0.9



Canister3

Primary

NA

Not performed





Carbonylb

Primary

1

Site: 0.6997 L/min (actual)
Audit: 0.7356 L/min (actual)

-4.9



Carbonyl

Duplicate/Collocated

2

Site: 0.7 L/min (actual)
Audit: 0.7196 L/min (actual)

-2.7



PM10e

Primary

NA

Site: 32.96 ft3/min (STP)
Audit: 32.16 ft3/min (STP)

2.5

Mayville, Wl

PM10e

Duplicate/Collocated

NA

Site: 32.96 ft3/min (STP)
Audit: 32.59 ft3/min (STP)

1.1



Cr(VI)

Primary

NA

Site: 14.7 L/min (actual)
Audit: 15.15 L/min (actual)

-3.0



Cr(VI)

Duplicate/Collocated

NA

Site: 14.7 L/min (actual)
Audit: 15.01 L/min (actual)

-2.1



PAH

Primary

NA

Site: 6.36 ft3/min (STP)
Audit: 6.52 ft3/min (STP)

-2.5



PAH

Duplicate/Collocated

NA

Site: 6.61 ft3/min (STP)
Audit: 6.61 ft3/min (STP)

0.0



Canister3

Primary

NA

Not performed





Carbonylb

Primary

1

Site: 1.18 L/min (actual)
Audit: 1.21 L/min (actual)

-2.5



PM10e

Primary

NA

Site: 41.7 ft3/min (STP)
Audit: 42.8 ft3/min (STP)

-2.6

Northbrook, IL

Cr(VI)

Primary

NA

Site: 14.4 L/min (actual)
Audit: 13.86 L/min (actual)

3.9



Cr(VI)

Duplicate/Collocated

NA

Site: 15.1 L/min (actual)
Audit: 14.76 L/min (actual)

2.3



PAH

Primary

NA

Site: 8.08 ft3/min (STP)
Audit: 8.23 ft3/min (STP)

-1.8

(continued)

41


-------
Table 15. Flow Audit Results from 2009 Instrument Performance Audits (continued).

Site Identifier

Method

Sampler

Channel

Measurements

Percentage
Difference



Canister3

Primary

NA

Not performed





Carbonylb

Primary

1

Site: 0.7493 L/min (actual)
Audit:0.771 L/min (actual)

-2.8



Carbonylb

Collocated/Duplicate

1

Site: 0.8897 L/min (actual)
Audit:0.9222 L/min (actual)

-3.5

St. Louis, MO

PMioe

Primary

NA

Site: 41.32 ft3/min (STP)
Audit: 39.71 ft3/min (STP)

4.1



Cr(VI)

Primary

NA

Site: 14.26 L/min (actual)
Audit: 14.31 L/min (actual)

-0.3



Cr(VI)

Duplicate/Collocated

NA

Site: 14.72 L/min (actual)
Audit: 14.46 L/min (actual)

1.8



PAH

Primary

NA

Site: 7.77 ft3/min (STP)
Audit: 7.78 ft3/min (STP)

-0.1

a VOC sampler.
b Carbonyl cartridge.
d Performed by RTI International.

11 Audit not performed for this sampler type.

6 Filter sample for PMi0 metals.

A graphical summary of the flow audit results is presented in Figure 23. All flow rate
measurements were within ฑ10% of the audit flow rate; most were within 5%.

Accuracy of flow rates for carbonyl and PMio samplers is critical for determining sample
concentration. Conversely, because only an aliquot of the canister volume is analyzed, the
accuracy of canister sampler flow rates is less important. However, a constant flow rate across
the 24-hour sampling interval is critical to achieving a linearly representative integrated sample.
The field bias audit of a VOC sampler flow rate is a random check of this time-integrated value.

2.6 Method Detection Limit Data

During compilation of 2007 QA data, substantial effort was invested in acquiring the
MDL data through direct contacts with each contributing laboratory. For the 2008 and 2009
results, the AQS database, specifically the ALTMDL variable in the RD record types, served as
the primary source of laboratory-based MDL data. Although this is not a required field in AQS,
approximately 85% of the MDL data were acquired from this source. Because AQS allows the
posting of MDL data in a variety of units, even within chemical classes, all AQS-acquired MDLs

3	3

were standardized to ng/m for metals, PAHs, and chromium (VI) and (J,g/m for carbonyls and
VOCs. The balance of the MDLs (i.e., those values not posted to AQS) was requested from
direct contact with each laboratory known to be providing analytical services. Multiple e-mail
requests with some laboratory contacts were needed to obtain the full complement of MDL data.
After careful review of the received materials from each laboratory, the spreadsheet information
was compiled into a database from which subsequent data analyses could be performed.

42


-------
Sample Type	Site Id.

Carbonyl Dearborn, MI
Deer Park, TX
Karnack, TX
Mayvile, Wl
Norttibrook, IL
St Louis, MO

Cr (VI) Dearborn, MI
Deer Park, TX
Karnack, TX
Mayvile, Wl
Narttibrook, IL
St Louis, MO

PAH	Dearborn, MI

Deer Park, TX
Karnack, TX
Mayvile, Wl
Narttibrook, IL
St Louis, MO

PM10 Dearborn, MI
Deer Park, TX
Karnack, TX
Mayvile, Wl
Narttibrook, IL
St Louis, MO

Figure 23. Summary of Instrument Performance Flow Audit Results for 2009.

For this report and by generally accepted conventions, MDLs are defined as the detection
threshold for a given analyte based on the mathematical combination of all aspects of the sample
collection and analysis process. Thus, they reflect, among other factors, the collected sample
volume for each sample, the size of the subsample subjected to analysis, and any sample
dilutions that may be associated with the analysis methodology. Using the AQS database as the
primary source of the MDL information does not, in and of itself, ensure consistency of the data,
but consistency of the data derived largely from posted information is considered vastly
improved over the same data obtained through individual laboratory requests. There is, however,
no unequivocal way to discern from the existing data if the MDLs provided reflect the MDL
(i.e., taking into account sampling and analysis components) or if they reflect only instrumental
detection limits. These concerns notwithstanding, the MDL results presented in this report are
mean values computed from either individual AQS-posted values or directly from laboratory
contacts and are presented under the assumption that each laboratory reported actual method
detection limits that incorporated both instrumental and sampling considerations. In cases where
the data were acquired by direct laboratory contact and unit conversions were needed, the data
were converted to the same units specified above. The MDL data for individual sites, in addition
to the mean across all sites reporting data, are shown in Table 16. Because ERG serves as the
analytical laboratory for numerous NATTS sites (Table 7) for VOCs, carbonyls, metals, and
particularly for chromium (VI) and PAHs, the method detection limits shown in Table 16 and in
Figures 24 - 28 reflect a consistency in instrumental detection limits associated with an analytical
laboratory common to multiple sites.

43


-------
Box and whisker plots and complementary scatter plots, shown in Figures 24 through 28,
illustrate the MDLs for carbonyls, metals, arsenic, VOCs, and PAHs, respectively. The MQOs
for benzene, 1,3-butadiene, formaldehyde, and arsenic are added to each plot for reference. Labs
whose results fell outside of a window defined by 1.5 x IQR are identified by blue asterisks on

44


-------
Table 16. Method Detection Limits by Site and Overall for Calendar Year 2009 (VOCs and Carbonyls: jig/m3; Metals: ng/m3).

Site Name

AQS Site Code

BENZ

BUTA

CTET

CLFRM

EDB

DCP

EDC

MECL

TCE 1122

PERC

TCE

VCM

c DCPEN

t DCPEN

Phoenix, AZ

04-013-9997

0.125

0.122

0.014

0.011

0.008

0.015

0.009

0.03

0.023

0.022

0.012

0.006

0.015

0.015

Los Angeles, CA

06-037-1103

	b

0.176

0.63

0.355

0.77

0.463

0.406

0.348

	b

0.469

0.39

0.256

0.455

0.455

Rubidoux, CA

06-065-8001

	b

0.172

0.63

0.344

0.77

0.463

0.406

0.348

	b

0.452

0.378

0.256

0.455

0.455

San Jose, CA

06-085-0005

0.112

0.113

0.063

0.068

0.077



0.406

0.348

	b

0.047

0.074

0.256

0.455

0.455

Grand Junction, CO

08-077-0017

b

b

b

b

b

b

b

b

b

b

b

b

b

b

Grand Junction, CO

08-077-0018

0.021

0.007

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

Washington, DC

11-001-0043

0.059

0.055

0.157

0.122

0.23

0.138

0.121

0.121

0.239

0.203

0.134

0.076

0.067

0.113

Hillsborough County, FL

12-057-3002

0.064

0.053

0.139

0.083

0.123

0.083

0.061

0.084

0.089

0.122

0.108

0.051

0.068

0.073

Pinellas County, FL

12-103-0026

0.064

0.053

0.139

0.083

0.123

0.083

0.061

0.084

0.089

0.122

0.108

0.051

0.068

0.073

Decatur, GA

13-089-0002

0.119

0.074

0.053

0.097

0.142

0.16

0.113

6.959

0.169

0.149

0.231

0.052

0.116

0.11

Northbrook, IL

17-031-4201

0.125

0.122

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

Grayson Lake, KY

21-043-0500

0.128

0.2

0.189

0.098

0.231

0.185

0.284

0.07

0.275

0.204

0.108

0.256

0.182

0.227

Boston, MA

25-025-0042

0.022

0.014

0.055

0.037

0.087

0.034

0.043

0.047

0.235

0.059

0.044

0.022

0.029

0.022

Dearborn, Ml

26-163-0033

0.021

0.007

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

St. Louis, MO

29-510-0085

0.021

0.007

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

Bronx, NY

36-005-0110

0.032

0.044

0.063

0.049

0.077

0.093

0.041

0.035

0.069

0.068

0.054

0.026

0.045

0.045

Rochester, NY

36-055-1007

0.032

0.044

0.063

0.049

0.077

0.093

0.041

0.035

0.069

0.068

0.054

0.026

0.045

0.045

Portland, OR

41-051-0246

0.143

0.222

0.315

0.245

b

0.232

b

0.261

b

0.34

0.269

0.154

b

b

La Grande, OR

41-061-0119

0.143

0.222

0.315

0.245

b

0.232

b

0.261

b

0.34

0.269

0.154

b

b

Providence, Rl

44-007-0022

0.024

0.014

0.055

0.037

0.087

0.034

0.043

0.047

0.235

0.059

0.044

0.022

0.029

0.022

Chesterfield, SC

45-025-0001

0.576

0.532

1.072

0.44

1.925

0.741

2.434

0.626

0.895

1.155

0.969

0.41

0.455

0.546

Deer Park, TX

48-201-1039

0.864

0.599

1.702

1.028

1.54

0.787

1.095

0.487

1.376

1.631

1.562

0.435

0.91

0.91

Harrison County, TX

48-203-0002

0.864

0.599

1.702

1.028

1.54

0.787

1.095

0.487

1.376

1.631

1.562

0.435

0.91

0.91

Bountiful, UT

49-011-0004

0.125

0.122

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

Underhill, VT

50-007-0007

0.019

0.02

0.027

0.021

0.049

0.018

0.017

0.034

0.085

0.028

0.02

0.015

0.02

0.026

Richmond, VA

51-087-0014

0.193

0.069

0.195

0.176

0.416

0.144

0.089

0.153

0.275

0.231

0.14

0.087

0.209

0.136

Seattle, WA

53-033-0080

0.021

0.007

0.013

0.01

0.008

0.014

0.008

0.028

0.021

0.02

0.011

0.005

0.014

0.014

Mayville, Wl

55-027-0007

0.357

0.222

0.63

0.489

0.77

0.463

0.406

0.348

0.688

0.68

0.539

0.256

0.455

0.455

Geometric Mean



0.089

0.071

0.104

0.076

0.103

0.091

0.075

0.114

0.121

0.122

0.091

0.049

0.08

0.081

Arithmetic Mean



0.179

0.147

0.318

0.202

0.379

0.215

0.293

0.419

0.304

0.317

0.274

0.128

0.212

0.217

Standard Deviation



0.24

0.169

0.473

0.279

0.546

0.252

0.531

1.294

0.415

0.456

0.425

0.143

0.271

0.274

Median



0.116

0.093

0.101

0.083

0.105

0.093

0.061

0.084

0.089

0.122

0.108

0.051

0.068

0.073

(continued)


-------
Table 16. Method Detection Limits by Site and Overall for Calendar Year 2009 (VOCs and Carbonyls: jig/m3; Metals: ng/m3)
	(additional analytes) (continued).	

Site Name

AQS Site Code

ACRY

ACRO

FORM

ACET

NAPH

BaP

AS

BE

CD

PB

MN

Nl

CRVI

Phoenix, AZ

04-013-9997

0.036

0.038

0.046

0.042

0.384

0.092

0.014

0.03

0.226

0.07

0.231

1.066

0.004

Los Angeles, CA

06-037-1103

0.653

0.388

b

b

0.378

0.093

b

b

b

b

b

b

b

Rubidoux, CA

06-065-8001

0.653

0.401

0.123

0.181

0.28

0.069

b

b

b

b

b

b

b

San Jose, CA

06-085-0005

0.324

0.426

0.123

0.181

0.337

0.082

0.024

0.002

0.046

0.438

0.378

0.658

	b

Grand Junction, CO

08-077-0017

	b

	b

	b

	b

	b

	b

1.583

0.205

0.179

1.112

0.392

0.45

0.004

Grand Junction, CO

08-077-0018

0.033

0.034

0.01

0.009

0.408

0.099

	b

	b

	b

	b

	b

	b

	b

Washington, DC

11-001-0043

0.054

b

0.026

0.029

0.383

0.093

1.18

0.18

0.31

0.84

0.19

0.78

0.005

Hillsborough County, FL

12-057-3002

0.061

0.143

0.011

0.01

0.336

0.081

0.46

0.2

0.15

1.04

0.14

0.92

0.005

Pinellas County, FL

12-103-0026

0.061

0.143

0.01

0.009

0.294

0.072

0.46

0.2

0.15

1.04

0.14

0.92

0.005

Decatur, GA

13-089-0002

	b

0.052

1.079

1.079

0.332

0.081

0.268

0.018

0.009

0.027

0.036

0.059

0.005

Northbrook, IL

17-031-4201

0.033

0.034

0.006

0.005

0.278

0.067

0.009

0.002

0.029

0.056

0.057

0.132

0.005

Grayson Lake, KY

21-043-0500

	b

0.391

0.008

0.022

0.277

0.067

0.413

0.253

0.243

0.247

0.414

0.578

0.4

Boston, MA

25-025-0042

b

0.116

0.08

0.108

0.258

0.062

0.009

0.002

0.029

0.056

0.057

0.138

0.005

Dearborn, Ml

26-163-0033

0.033

0.034

0.009

0.009

0.324

0.079

0.173

0.244

0.166

0.22

0.412

0.16

0.005

St. Louis, MO

29-510-0085

0.033

0.034

0.01

0.009

0.27

0.067

0.016

0.002

0.037

0.816

0.108

0.517

0.005

Bronx, NY

36-005-0110

	b

0.069

0.012

0.018

0.302

0.075

0.521

0.521

0.26

0.26

0.521

0.521

0.005

Rochester, NY

36-055-1007

	b

0.069

0.012

0.018

0.231

0.056

0.521

0.521

0.26

0.26

0.521

0.521

0.005

Portland, OR

41-051-0246

	b

	b

0.118

0.03

1.206

0.251

0.033

0.003

0.033

0.334

0.334

0.334

0.033

La Grande, OR

41-061-0119

b

b

0.122

0.03

1.801

0.255

0.037

0.004

0.037

0.367

0.367

0.367

0.036

Providence, Rl

44-007-0022

0.265

0.116

0.046

0.027

0.381

0.094

0.057

0.014

0.016

0.024

0.026

0.017

0.005

Chesterfield, SC

45-025-0001

b

1.953

0.249

0.197

0.347

0.085

0.031

0.001

0.001

0.003

0.002

0.003

0.005

Deer Park, TX

48-201-1039

	b

0.23

0.098

0.145

0.341

0.083

0.015

0.18

0.098

1.3

0.57

2.3

0.012

Harrison County, TX

48-203-0002

	b

0.23

0.098

0.145

	b

	b

0.015

0.18

0.098

1.3

0.57

2.3

0.012

Bountiful, UT

49-011-0004

0.033

0.034

0.009

0.008

0.431

0.105

0.031

0.045

0.19

0.098

0.205

0.835

0.004

Underhill, VT

50-007-0007

0.037

0.04

0.014

0.017

0.33

0.081

0.011

0.001

0.066

0.591

0.258

1.223

0.005

Richmond, VA

51-087-0014

0.089

0.179

0.055

0.043

0.379

0.092

0.037

0.011

0.007

0.032

0.042

0.312

0.005

Seattle, WA

53-033-0080

0.033

0.034

0.014

0.013

0.276

0.067

0.01

0.003

0.027

0.062

0.073

0.138

0.005

Mayville, Wl

55-027-0007

	b

0.23

0.331

1

0.283

0.069

0.028

0.01

0.011

0.004

0.015

0.093

0.005

Geometric Mean



0.075

0.116

0.04

0.042

0.358

0.085

0.062

0.023

0.053

0.159

0.138

0.304

0.007

Arithmetic Mean



0.152

0.226

0.115

0.162

0.412

0.092

0.23

0.109

0.104

0.409

0.237

0.594

0.023

Standard Deviation



0.214

0.383

0.217

0.317

0.329

0.048

0.388

0.152

0.097

0.441

0.189

0.609

0.079

Median



0.046

0.116

0.046

0.029

0.332

0.081

0.032

0.016

0.056

0.254

0.197

0.484

0.005

' Meets MQO.
b Not reported.


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Grand Junction, CO
Grayson Lake, KY
Harris County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA
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Northbrook, IL
Phoenix, AZ
Pinelas County, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
San Jose, CA
Seattle, WA
St Loiis, MO
Underbill, VT
Washington, DC

Figure 24. Distribution of Method Detection Limits for Carbonyls for 2009 NATTS Data
(dashed line indicates MQO target MDL for formaldehyde; > 1.5 x IQR are identified as

blue stars in top display).

47


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La Grande, OR
Los Angeles, CA
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Northbrook, IL
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Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
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Seattle, WA
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Underbill, VT
Washington, DC

Figure 25. Distribution of Method Detection Limits for Metals for 2009 NATTS Data
(dashed line indicates MQO target MDL for arsenic; > 1.5 x IQR are identified as blue

stars in top display).

48


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Bronx, NY
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Deer Park, TX
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Grayson Lake, KY
Harris County, TX
Hillsborough County, FL
La Grande, OR
Los Angeles, CA
Mayville, Wl
Northbrook, IL
Phoenix, AZ
Pinelas County, FL
Portland, OR
Providence, Rl
Richmond, VA
Rochester, NY
Rubidoux, CA
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Seattle, WA
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Figure 26. Distribution of Method Detection Limits for Arsenic for 2009 NATTS Data
(dashed line indicates MQO target MDL for arsenic.

49


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the graphical display. The IQR is defined as the distance between the 25th and 75th percentiles of
the distribution of values.

51


-------
Review of the graphically displayed MDL results reveals a number of interesting features
largely consistent with previous reporting years. MDLs for carbonyls (Figure 24) show
appreciable spread across laboratories but almost universally greater than the MQO. The
proximity of the mean MDL to the bottom of the distribution reflects the MDLs for many
laboratories close to, albeit above, the MQO; values for two laboratories are significantly higher,
particularly for acetaldehyde. Metals results in Figures 25 and 26 show MDL values falling
within the MQO for some analytes, notably Be, Cd, and chromium (VI), but substantially above
for others (Mn, Ni, Pb), with relatively few values outside the IQR. Arsenic performance was
well within the MQOs for some laboratories but substantially outside for others. The consistency
and magnitude of MDLs reported for chromium (VI) is particularly noteworthy and may reflect
the fact that only three laboratories are performing this analysis for all NATTS sites. VOCs show
much greater variability in MDLs across laboratories than other analyte groups, with a few sites
accounting for most of the spread in the distribution (Figure 27). As was found for most analytes,
a high proportion of MDLs for VOCs occurred above the MQO. Lastly, MDLs for PAHs, while
universally above the MQO, tended to be clustered for both benzo[a]pyrene and naphthalene,
again reflecting that the analysis was performed by only three labs (Figure 28).

As reported by the metals analysis laboratories for 2008, 19 NATTS sites (San Jose, CA;
Washington, DC; Boston-Roxbury, MA; Decatur, GA; Hillsborough County, FL; Pinellas
County, FL; Dearborn, MI; Mayville, WI; Northbrook, IL; Harrison County, TX; St. Louis, MO;
La Grande, OR; Portland, OR; Seattle, WA; Providence, RI; Chesterfield, SC; Deer Park, TX;
Underhill, VT; Richmond, VA) collected high-volume PMio metals on 8 in. x 10 in. quartz fiber
filters. Seven sites reported using low-volume PMio metals sampling on 47 mm Teflon filters
(Bronx, NY; Rochester, NY; Bountiful, UT; Grand Junction, CO; Phoenix, AZ; Hazard, KY;
Grayson Lake, KY). The remaining sites either did not collect PMio samples for metals analysis
or did not report the type of sampling implemented.

Comparison of MDLs for the two sampling approaches is meaningful only when the
analysis laboratory is the same for the two sites; otherwise the variability in MDLs is an
aggregate effect of sample collection and sample analysis. The metals results provided by the
ERG laboratory, which analyzes samples of both types, offer a unique opportunity to examine
MDLs between high- and low-volume sampling without the influence of cross-laboratory
instrumental detection limit variability. Table 17 shows the MDLs for each of the PMio metal
analytes. The enhanced MDLs for the higher volume samples are consistent with the 100-fold
increase in sample size over the lower volume samples. At the direction of EPA, the computation
of the MDLs by the laboratories for quartz sampling media was changed, allowing for
adjustment of the significantly higher background levels for this collection medium. Overall,
variability in MDLs among laboratories, shown in Table 18, is very large and suggests
significant differences in analytical performance as well as collection volumes.

52


-------
Table 17. Comparison of Method Detection Limits Reported by ERG Laboratory for
Metals between High- and Low-Volume Samplers in Calendar Year 2009.



Method Detection Limits (ng/m3)
Median (Std. Dev.)

MDL Ratio
(High/Low)

Analyte

2000 m3
Samples3

20 m3
Samples'1

Arsenic

0.0090 (0.0239)

0.0200 (0.0169)

0.45

Beryllium

0.0020 (0.0014)

0.0300 (0.0259)

0.067

Cadmium

0.0290 (0.0185)

0.2300 (0.0713)

0.13

Chromium (VI)

0.0046 (0.0008)

0.0043 (0.0006)

1.07



0.0170 (0.0170)

1.1600 (0.0381)

0.015

Manganese

0.0570 (0.2795)

0.2400 (0.0630)

0.24

Nickel

0.1320 (0.6573)

1.0300 (0.4958)

0.13

Lead

0.0560 (0.7785)

0.0700 (0.0677)

0.80

'Based on six sites conducting high-volume PMi0 sampling.
b Based on two sites conducting low-volume PMi0 sampling.

The geometric mean MDLs (Table 18) for the select analytes—benzene, 1,3-butadiene,
and formaldehyde—do not meet the target MQO for MDLs. Conversely, the MDL for arsenic
falls within the target MQO.

Table 18. Summary Statistics for Method Detection Limits across All Reporting NATTS

Laboratories for 2009.





Selected Analyte



MDL

Benzene, (pg/m3)

1,3-butadiene,
(Mg/m3)

Formaldehyde,
(Mg/m3)

Arsenic, (ng/m3)

Geometric Mean

0.063

0.0369

0.0402

0.0639

Arithmetic Mean

0.103

0.0773

0.1132

0.5119

Standard Deviation

0.102

0.0786

0.2377

1.1656

Minimum

0.010

0.0067

0.0049

0.0090

Median

0.071

0.0532

0.0400

0.0340

Maximum

0.357

0.2217

1.0800

5.3311

MQO

0.016

0.013

0.0074

0.217

Ratio of Geo. Mean
to MQO

3.9

2.8

5.4

0.3

3.0 SUMMARY

Based on four HAPs representative of the various chemical classes—benzene, 1,3-
butadiene, formaldehyde, and arsenic, the following summary comments are appropriate for the
2009 NATTS data.

53


-------
1.	Excluding NATTS sites intentionally not collecting data for a particular analyte class
(e.g., PMio metals), the mean completeness percentages of data reported into AQS
across all NATTS sites were 97%, 98%, 98%, 98%, 99%, 99%, and 98% for benzene,
1,3-butadiene, acrolein, naphthalene, formaldehyde, chromium (VI), and arsenic,
respectively. Completeness statistics reported in 2009 for naphthalene and chromium
(VI) were dramatically improved over those reported in 2008, exceeding the MQO
for nearly every site. Overall, the MQO was achieved for all seven analytes.

2.	With a few exceptions as noted in the text of this report, analytical precision among
sites for which replicate analyses were available was found to be below the 15%
MQO threshold for all analytes used to reflect their respective chemical classes.
Analytical precision for acrolein was somewhat more variable than other analytes but
still within the 15% threshold. As expected, the frequency of cases where the MQO
threshold was exceeded was distinctly greater for overall precision (i.e., including
sampling and analysis) among all analytes and particularly for acrolein, an analyte
presenting unique collection and analysis challenges. Estimates of overall precision
included both duplicate and collocated samples.

3.	Laboratory performance, as assessed by the percentage difference between the
laboratory measurement and the certified sample concentration of the proficiency
testing samples, was within the ฑ25% MQO for most analytes (i.e., benzene, 1,3-
butadiene, formaldehyde, and arsenic) and for laboratories with available data from
2009. The poorest performance across all laboratories and analytes was observed for
lead (37.6%>) and acrolein (30.3%). The proportion of laboratories participating in the
2009 performance testing program was 100% for all chemical classes—a significant
improvement over participation in 2008. Laboratories not performing analyses of a
particular analyte were excluded from these statistics.

4.	Without exception, sampler flows measured during IP As conducted at NATTS field
sites showed less than ฑ10% difference from their site-recorded values.

5.	Among all measures of data quality, MDLs were substantially greater than the
corresponding MQOs and showed substantial variability for any given analyte across
sites (i.e., laboratories). Only the mean value for arsenic fell within the MQO
threshold when all laboratories were considered together. The ratios of the cross-
network geometric means to the corresponding MQOs were 3.9, 2.8, 5.4, and 0.3 for
benzene, 1,3-butadiene, formaldehyde, and arsenic, respectively.

4.0 RECOMMENDATIONS

The information, both analytical results and site characteristics, for the NATTS network
samples present in the AQS database was acquired successfully, based on a thorough
understanding of the database structure. Based on knowledge of POC assignments in previous
years, the POCs for the primary, duplicate, and collocated samples were assigned with greater
facility than in previous years. However, as in previous years, acquiring MDL data for
laboratories not posting MDLs to AQS directly was still problematic.

The POCs are present in the AQS database, but the associated sample type information
(e.g., primary, duplicate, or collocated) is not. Because POCs are assigned by either the agency
monitoring a particular NATTS site or the laboratory uploading the data to AQS, and are largely

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nonstandardized across NATTS sites [5, 6] (see Table 6), the inclusion of a field in the AQS
database to specify whether a particular POC is "primary," "duplicate," or "collocated" would be
of enormous benefit to the utility of the AQS data and would greatly streamline the analyses
reported here.

Summary statistics created for this report reflect the overall condition of the data but
may, in some cases, be unduly influenced by selected extreme values. Instances where the
summary statistics fall outside of the MQOs warrant further investigation of the individual data
points as deemed appropriate by EPA.

The acquisition and assembly of MDL information was again aided dramatically through
the extraction of the ALTMDL field for RD records in the AQS database. Only instances where
this optional field was not populated by the contributing laboratory (-15%) required direct
contacts with individual laboratory supervisors. Changing the character of this AQS field to
"required" would completely eliminate the need for this follow-up step. Lastly, AQS accepts
data in a variety of units at the discretion of the agency performing the upload. This requires very
careful scrutiny of the UNIT variable so that MDL measurements can be standardized
algebraically prior to data analysis. Standardization of MDLs posted in the ambiguous "ppbC"
unit is particularly problematic.

5.0 REFERENCES

1.	U.S. Environmental Protection Agency. (October 17, 2008). AQS Data Coding Manual
(Version 2.33). Available at

http://www.epa.gov/ttn/airs/airsaqs/manuals/AQS%20Data%20Coding%20Manual.pdf

2.	Eastern Research Group. (January 1, 2007). Technical Assistance Document for the National
Ambient Air Toxics Trends and Assessment Program.

3.	U.S. Environmental Protection Agency. (July 2004). Final Draft, July 2004, National
Monitoring Strategy, Air Toxics Component. Available at
http://www.epa.gov/ttn/amtic/files/ambient/airtox/atstrat804.pdf

4.	U.S. Environmental Protection Agency. (2007). National Air Toxics Trends Stations Quality
Assurance Annual Report - Calendar Year 2006. Prepared by Battelle Memorial Institute.

5.	U.S. Environmental Protection Agency. (2009). National Air Toxics Trends Stations Quality
Assurance Annual Report - Calendar Year 2007. Prepared by RTI International.

6.	U.S. Environmental Protection Agency. (2010). National Air Toxics Trends Stations Quality
Assurance Annual Report - Calendar Year 2008. Prepared by RTI International.

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