EPA/600/R-09/135 November 2009 www.epa.gov/ord 

A Scoping-Level Field Monitoring Study of 

Synthetic Turf Fields and Playgrounds 

Prepared by the 

National Exposure Research Laboratory 

Office of Research and Development 

U.S. Environmental Protection Agency 

with contributions from the Agency’s 

Tire Crumb Science Workgroup 
Disclaimer 

The information in this document has been funded by the U.S. Environmental 

Protection Agency. It has been subjected to the Agency’s peer and administrative 

review and has been approved for publication as an EPA document. Mention of 

trade names or commercial products does not constitute endorsement or 

recommendation for use.

ii
Acknowledgments 

This report was prepared for the U.S. Environmental Protection Agency (EPA) Tire 

Crumb Committee, a cross-Agency workgroup led by Michael Firestone, Office of Children's 

Health Protection and Environmental Education, and Ross Highsmith, National Exposure 

Research Laboratory (NERL)/Office of Research and Development (ORD). A smaller Science 

Workgroup was organized to consider options for collecting additional data from a small number 

of U.S. synthetic turf fields and playgrounds. Initial Science Workgroup members included Cathy 

Fehrenbacher, Office of Pollution Prevention and Toxics; Peter Grevatt and Tim Taylor, Office of 

Solid Waste and Emergency Response; Linda Sheldon and Kent Thomas NERL/ORD; Urmila 

Kodavanti, National Health and Environmental Effects Research Laboratory/ORD; Souhail 

Al-Abed, National Risk Management Research Laboratory/ORD; Jacqueline Moya, National 

Center for Environmental Assessment/ORD; Jacqueline McQueen, Office of Science 

Policy/ORD; Nora Conlon, Region 1; Mark Maddaloni, Region 2; Patti Tyler, Region 8; Arnold 

Den, Region 9; and Dale Kemery, Office of Public Affairs. Some of the workgroup members 

changed as the study progressed. NERL designed and implemented the limited scoping study 

described in this report based on the Science Workgroup discussions and the availability of 

resources. 

Ross Highsmith, Kent Thomas, Ron Williams, Don Whitaker, Sharon Harper, Karen 

Bradham, Easter Coppedge, Fu-Lin Chen, Teri Conner, Bob Willis, Carry Croghan, and Jeff 

Morgan from NERL/ORD; Dennis Revel from Region 4; and Dan Boudreau and Dan Curran 

from Region 1 contributed to the field sampling, sample analysis, and data compilation efforts. 

Laboratory support was provided through the Senior Environmental Employment (SEE) and 

Student Services Contracting Authority programs by Tom Gilmore, Charlie Bare, James Polk, 

Doug Tilly, Lin Li, and Elena Arthur. Elizabeth Betz of NERL/ORD provided quality assurance 

guidance and review. Numerous EPA program office, regional office, State, and local scientists 

and staff provided valuable scientific input for use in developing the study design and technical 

assistance in the implementation of the field study, especially gaining access to monitoring 

sites. This study could not have been planned and implemented without their valuable 

contributions. 

iii
iv
Abstract 

Recycled tire material, or “tire crumb,” is used as a component in many recreational 

fields, including synthetic turf fields and playgrounds. The use of tire crumbs in these 

applications provides several benefits, including reduced sports injury. The public recently has 

raised concerns regarding potential human health and environmental risks associated with the 

presence of and potential exposures to tire crumb constituents in recreational fields, especially 

with regard to children’s exposures. 

In early 2008, U.S. Environment Protection Agency (EPA) Region 8 requested that the 

Agency consider this issue. A cross-EPA workgroup inventoried and considered the limited 

available scientific information: some laboratory studies of tire material content, off-gassing, and 

leaching characteristics and a few European studies describing the extent and availability of tire 

crumb constituents for potential human exposure. The workgroup recommended that research 

be conducted to generate additional field monitoring data for potential U.S. environmental 

conditions and potential exposures. 

A limited-scale study was conducted during the 2008 summer and fall seasons to 

(1) gain experience conducting multiroute field monitoring of recreational surfaces that contain 

tire crumb by evaluating readily available methods for measuring environmental 

concentrations of tire crumb constituents; and 

(2) generate limited field monitoring data that will be used by EPA to help the Agency determine 

possible next steps to address questions from the public regarding the safety of tire crumb 

infill in recreational fields. 

The field sites were selected based on availability and proximity to facilities of EPA’s 

National Exposure Research Laboratory; thus, the results reported here may not be 

representative of environmental concentrations found at other sites. Because validated methods 

for sampling synthetic turf fields or playgrounds did not exist, methods used for other 

microenvironmental sampling were used. The full study protocol was implemented at two 

synthetic turf fields and one playground. At each field and the playground, air sampling was 

conducted to collect integrated particulate matter (PM10) and grab volatile organic chemical 

(VOC) samples at two to three locations on each turf field and playground and also at an upwind 

background location. The air samples were collected at a height of 1 m in close proximity to, but 

without interfering with, planned recreational activities. The VOC samples were collected around 

2:00 p.m. Wipe samples were collected at the three turf field sampling locations, along with 

readily available tire crumb infill and turf blade samples. Tire crumb material was collected from 

the playground. The full protocol was implemented at one of the synthetic turf fields on a second 

consecutive day providing repeat sampling data. Selected samples were collected at a few 

additional synthetic turf fields and one playground. 

 Standard laboratory analysis methods were employed to analyze the environmental 

samples for the targeted analytes. The PM10 samples were analyzed for PM mass, metals, and 

particle morphology. The VOC samples were analyzed for 56 volatile organic analytes. The 

wipe and material samples were analyzed for total extractable concentrations of several metals 

and bioaccessible lead. 

 Key findings are summarized below. 

(1) The study protocol and many of the methods were found to be reliable and could be 

implemented in the field. Several limitations are noted below. 

a. Collecting integrated air samples provided a high burden in terms of time and equipment. 

b. Semivolatile organic compounds were not measured. 

c. At any single site, there can be substantial variability in the materials used and the 

concentrations of contaminants measured. More work is needed to determine where to 

collect samples and how many samples to collect to fully characterize a given site. 

v
d. It was difficult to obtain access and permission to sample at playgrounds and synthetic 

turf fields. More work is needed to increase public and private owner participation if 

additional monitoring studies are conducted. 

(2) Methods used to measure air concentrations of PM10 and metals were found to be reliable. 

a. Concentrations of PM10 and metals (including lead) measured in air above the turf fields 

were similar to background concentrations. 

b. Concentrations of PM10 and metals at the playground site with high play activity were 

higher than background levels. 

c. All PM10 air concentrations were well below the National Ambient Air Quality Standards 

(NAAQS) for PM10 (150 μg/m3

). All air concentrations for lead were well below the 

NAAQS for lead (150 ng/m3

). 

(3) Methods used to measure VOCs in air were found to be reliable. 

a. All VOCs were measured at extremely low concentrations that are typical of ambient air 

concentrations. 

b. One VOC associated with tire crumb materials (methyl isobutyl ketone) was detected in 

the samples collected on one synthetic turf field but was not detected in the 

corresponding background sample. 

(4) Methods used to measure extractable metals from turf field blades, tire crumb materials, and 

turf field wipe samples were found to be reliable. However, the aggressive acid extraction 

procedure likely will overestimate the concentration of metals that are readily available for 

human uptake. Since understanding uptake is a key component in understanding risk, 

methods to determine bioavailable metal concentrations still are needed. 

a. Total extractable metal concentrations from the infill, turf blade samples and tire crumb 

material were variable in the samples collected at a given site and between sites. 

b. The average extractable lead concentrations for turf blade, tire crumb infill, and tire crumb 

rubber were low. Although there are no standards for lead in recycled tire material or 

synthetic turf, average concentrations were well below the EPA standard for lead in soil 

(400 ppm). 

c. Likewise the average extractable lead concentrations for turf field wipe samples were 

low. Although there are no directly comparable standards, average concentrations were 

well below the EPA standard for lead in residential floor dust (40 μg/ft2

). 

(5) On average, concentrations of components monitored in this study were below levels of 

concern; however, given the very limited nature of this study (i.e., limited number of 

components monitored, samples sites, and samples taken at each site) and the wide 

diversity of tire crumb material, it is not possible to reach any more comprehensive 

conclusions without the consideration of additional data. 

vi
Table of Contents 

List of Tables................................................................................................................................ ix 

List of Figures .............................................................................................................................. ix 

Executive Summary................................................................................................................... xi 

1. Introduction.............................................................................................................................1 

1.1 Background .................................................................................................................1 

1.2 Exposure Science Questions ......................................................................................2 

1.3 Project Objectives .......................................................................................................2 

1.4 Study Limitations.........................................................................................................3

2. Conclusions and Recommendations....................................................................................4 

2.1 Implementation of the Study Protocol .........................................................................4 

2.2 Air Sampling and Analysis ..........................................................................................4 

2.3 Surface Wipe, Tire Crumb, and Turf Blade Sampling and Analysis............................5 

2.4 Conclusions with Regard to the Exposure Science Questions ...................................5 

3. Scoping Study Approach.......................................................................................................7 

3.1 Scoping Study Goals...................................................................................................7 

3.2 Organizations ..............................................................................................................7 

3.3 Selection of Target Analytes .......................................................................................7 

3.4 Proposed Sampling Sites and Sampling Locations ..................................................10 

3.5 Sampling Considerations ..........................................................................................11 

3.5.1 Material Variability ......................................................................................11 

3.5.2 Activity Variability .......................................................................................11 

3.5.3 Sample Volume for Detection Limit ............................................................12 

3.5.4 Meteorological Conditions ..........................................................................12 

3.5.5 Background Contribution............................................................................12 

4. Methods .................................................................................................................................13 

4.1 Air VOC Samples ......................................................................................................13 

4.2 Air PM10 Particle Samples for Mass and Metals Concentrations..............................13 

4.3 Air PM10 Particle Sample Collection for Scanning Electron Microscopy ...................13 

4.4 Surface Wipe Sample Collection―Synthetic Turf Fields ..........................................13 

4.5 Tire Crumb Infill Material Sample Collection―Synthetic Turf Fields.........................14 

4.6 Blade Material Sample Collection―Synthetic Turf Fields.........................................14 

4.7 Tire Crumb Material Sample Collection―Playgrounds.............................................14 

4.8 SEM Sample Preparation and Analysis ....................................................................15 

4.8.1 Sample Preparation....................................................................................15 

4.8.2 SEM Sample Analysis ................................................................................15 

4.9 Surface Wipe, Tire Crumb, and Turf Blade Sample Metals Analysis........................15 

4.10 Pb Bioaccessibility Analysis ....................................................................................17 

4.10.1 In Vitro Bioaccessibility Background Information......................................17 

4.10.2 In Vitro Pb Bioaccessibility Methodology..................................................17 

4.11 Meteorological and Activity Information...................................................................18 

5. Quality Control and Quality Assurance ..............................................................................19 

5.1 Air VOC Quality Control ............................................................................................19 

vii
5.2 Air PM10 Mass Quality Control ..................................................................................20 

5.3 Air PM10 Metals Quality Control ................................................................................20 

5.4 Air PM10 SEM Quality Control...................................................................................20 

5.5 Wipe, Tire Crumb, and Turf Blade Sample Quality Control and Quality 

 Assurance .................................................................................................................20 

5.5.1 Instrument Performance.............................................................................20 

5.5.2 Recoveries .................................................................................................21 

5.5.3 Analysis of Blank Materials ........................................................................21 

5.5.4 Measures of Precision................................................................................22 

5.6 In Vitro Bioaccessibility Analysis Quality Control and Quality Assurance .................22 

5.7 Data Quality Assurance Review................................................................................22 

6. Results...................................................................................................................................23 

6.1 Sampling Sites ..........................................................................................................23 

6.2 Site Characteristics ...................................................................................................24 

6.3 Sample Collection .....................................................................................................25 

6.4 Summary Measurement Results...............................................................................30 

6.5 Air VOC Measurement Results .................................................................................30 

6.6 Air PM10 Mass Measurement Results.......................................................................34 

6.7 Air PM10 Metal Measurement Results.......................................................................34 

6.8 Air PM10 SEM Measurement Results........................................................................35 

6.9 Total Extractable Metals in Synthetic Turf Field Surface Wipe, Tire Crumb 

 Infill, and Turf Blade Samples and Playground Tire Crumb Rubber Samples ..........35 

6.9.1 Surface Wipes from Synthetic Turf Fields ..................................................36 

6.9.2 Tire Crumb Infill at Synthetic Turf Fields ....................................................36 

6.9.3 Turf Blades at Synthetic Turf Fields ...........................................................37 

6.9.4 Tire Crumb Material from Playgrounds.......................................................37 

 6.9.5 Lessons Learned with Regard to the Sampling and Analysis of Tire 

 Crumb Materials.........................................................................................38

6.10 Pb Bioaccessibility Results .....................................................................................39 

 6.10.1 Analysis of Turf Field Wipe, Tire Crumb, and Turf Blade Samples..........39 

 6.10.2 Lessons Learned with Regard to Bioaccessibility Data............................39 

6.11 Methods Evaluation Summary ................................................................................40 

7. References.............................................................................................................................43

Appendix A: List of Sample Collection and Analysis Methods....................................................44 

Appendix B: Quality Control and Quality Assurance Results......................................................45 

Appendix C: Results from Analysis of Environmental Samples..................................................74 

Appendix D: NERL Report: SEM Analysis of Tire Crumb Samples............................................89 

viii
List of Tables 

Table 1. Summary of Sample Collection and Analysis Methods ..................................................8 

Table 2. Sampling Site Information and Assigned Codes...........................................................23 

Table 3. Overview of the Types of Samples Collected at Each Site...........................................23 

Table 4. Site Information.............................................................................................................25 

Table 5. Number of Samples Collected at Each Site..................................................................28 

Table 6. Summary Results for Selected Analytes in Air Samples Collected at Synthetic 

Turf Fields and a Playground......................................................................................................31 

Table 7. Summary Results for Total Extractable Pb, Cr, and Zn in Samples Collected at 

Synthetic Turf Fields and Playgrounds .......................................................................................32 

Table 8. Summary Results for Estimates of Pb Bioaccessibility in Samples Collected at 

Synthetic Turf Fields and Playgrounds .......................................................................................33 

Table 9. Overall Summary and Assessment of Methods Applied in This Scoping Study ...........41 

List of Figures 

Figures 1 through 4. Site F1 particle air samplers, surface wipe sample collection, green 

turf blade with black granular tire crumb, and multiple turf blade colors. ....................................26 

Figures 5 through 8. Tire crumb infill granules from site F2, shredded tire crumb at site P1, 

and molded tire crumb material from site P2. .............................................................................27 

ix
x
Executive Summary

Background 

Recycled tire material, or “tire crumb”, is used in many applications, including as a 

component in synthetic turf fields and playground installations. The use of tire crumbs in these 

applications provides several benefits, including but not limited to reduced impact injuries; 

reduced or eliminated use of water, fertilizer, and pesticides needed to maintain grass fields; 

reduced need for disposal of used tires in landfills; and increased availability of fields for 

recreation. The public recently has raised concerns regarding potential human health and 

environmental risks associated with the presence of and potential exposures to tire crumb 

constituents in recreational fields, especially with regard to children’s exposures. 

In early 2008, U.S. Environmental Protection Agency (EPA) Region 8 requested that the 

Agency consider this issue, and a cross-EPA workgroup was formed. The workgroup 

inventoried and considered the limited available scientific information: laboratory studies of tire 

material content, off-gassing, and leaching characteristics. Also, a few European studies 

reported data describing the extent and availability of tire crumb constituents for potential 

human exposure through various routes and pathways (inhalation, ingestion, and dermal 

contact). 

In the late spring of 2008, a smaller EPA Tire Crumb Science Workgroup (science 

workgroup) subsequently was formed and charged to consider the quality of the current science 

and make recommendations regarding the need for future research. Because minimal 

environmental or exposure data for U.S. populations were available, a limited scoping study was 

proposed and designed to evaluate a protocol and methods for generating consistently collected 

U.S. environmental data for select tire crumb constituents. 

 This report provides the EPA scoping study results. The EPA scoping study results, 

along with results from other studies conducted by Federal, State, and local organizations, such 

as the Consumer Product Safety Commission (CPSC); the Agency for Toxic Substances and 

Disease Registry; States including New Jersey, Connecticut, California, and New York; and 

New York City, will be considered by EPA to identify possible next steps to address questions 

from the public regarding the safety of tire crumb infill in ball fields and playgrounds. 

Scoping Study Objectives 

The EPA science workgroup proposed a limited scoping-level study during 2008 that 

included the following elements. 

• Evaluate, through real-world measurements, the application of readily available sampling and 

analysis methods for characterizing environmental concentrations of selected tire crumb 

contaminants in and around playgrounds and synthetic turf fields. 

• Evaluate the overall study protocol (monitoring, analytical, and quality control [QC] 

procedures) for generating the quantity and quality of environmental measurement data 

needed to characterize the contribution of the tire crumb constituents to environmental 

concentrations. 

• Collect a limited environmental dataset to help understand and assess methods for 

characterizing potential route- and pathway-specific exposures (inhalation, ingestion, and 

dermal) based on selected sentinel species. 

• Generate a limited set of consistently collected field measurement data from a very few 

playgrounds and synthetic turf fields that, along with other study data, may be used to 

develop insights regarding the importance of the various exposure routes and pathways and 

to inform decisions regarding possible next steps to address questions from the public 

regarding the safety of tire crumb infill in ball fields and playgrounds. 

xi
Study Approach 

The proposed final study design included the collection and analysis of selected air, 

wipe, and material samples at one playground and one synthetic turf field site in the EPA 

regions where the four National Exposure Research Laboratory (NERL) facilities are located. 

This design (a total of eight sites) was based on the availability of NERL technical support. 

During a single daytime period at each site, air samples were to be collected at up to three “on 

field” or “on playground” sampling locations within the site boundaries in areas as close to 

anticipated human activity as possible without interfering with routine activities. Air samples also 

were to be collected at site background upwind sampling locations to characterize local ambient 

background levels. A comparison of “on playground” or “on field” data with the background data 

would be used to characterize the environmental availability of tire crumb constituents. Surface 

wipe samples were to be collected at the “on field” air sampling locations, but not at the 

background sampling location. Tire crumb and synthetic turf blade samples were to be collected 

at multiple sampling locations, but these were not always the same locations as the air sampling 

locations. The following samples were planned for collection and analysis. 

• Grab air samples during the hottest daytime period (~2:00 p.m.) to assess organic vapor 

concentrations (56 volatile organic compounds [VOCs]) 

• Integrated air particulate matter (PM10) samples to assess particle mass concentrations and 

concentrations of selected metals (including lead [Pb], chromium [Cr], zinc [Zn], and others) 

• Integrated air PM10 samples to characterize ambient particles based on morphology (sizes 

and structure) using scanning electron microscopy (SEM) and, if possible, to estimate the 

relative contribution of tire crumb particles to the overall particle mass 

• Wet surface wipe samples to assess environmental concentrations of metals (e.g., Pb, Cr, Zn, 

and others) associated with turf field materials (tire crumb rubber and turf blades) 

• Turf field tire crumb infill granules, turf blades, and playground tire crumb material to assess 

concentrations of metals (e.g., Pb, Cr, Zn, and others) associated with these materials 

• Field and laboratory QC samples to document the quality of the study data. Duplicate 

samples for each measure described above were collected where appropriate. Routine field 

and laboratory QC samples (e.g., blanks, spikes) also were analyzed. 

Study Limitations 

This limited scoping-level study was designed to evaluate the methods for generating 

quality environmental data for selected tire crumb constituents and for understanding potential 

exposure routes and pathways. The study was planned based on readily available resources 

(personnel, equipment, media, etc.) and in consideration of the workgroup’s desired study time 

period (the summer and early fall of 2008). This time period was recommended, as the 

projected high ambient temperatures should result in conditions promoting the greatest potential 

for the environmental release of tire-related constituents. 

This study and the resulting data have many limitations. The study was not designed to 

provide representative U.S. environmental measurement data for all tire crumb constituents or 

applications. Nor was the study designed to inform conclusions regarding differences in U.S. 

environmental concentrations or potential exposures to turf field and playground tire crumb 

constituents based on geographical location, type, manufacturing materials, age, use, or 

conditions. The study also was not designed to compare potential exposures to turf field and 

playground tire crumb constituents with those at natural turf fields or playgrounds constructed 

with other types of surfaces. The study collected limited environmental data to help understand 

and assess methods for characterizing potential route- and pathway-specific exposures 

(inhalation, ingestion, and dermal) based on selected sentinel species. No personal exposure 

data or related information were collected. Validated sampling and analysis methods for 

characterizing recreational fields were not available, so existing methods used in similar studies 

xii
were applied. The study did not evaluate methods for all the reported tire crumb constituents. 

Semivolatile organic compounds (SVOCs [e.g., benzothiazole, aniline, polycyclic aromatic 

hydrocarbons (PAHs)]) reported in some studies were not sampled or analyzed because of 

resource limitations. 

Sample Collection Results 

Sampling Sites 

The full study protocol was implemented at only two synthetic turf field sites (F1 and F4) 

and one playground site (P1), fewer than the planned four turf field and four playground sites. 

Difficulties in identifying and arranging site access, logistical limitations, and personnel 

requirements to operate the extensive array of equipment and sites were the key factors 

impacting the number of sites monitored. 

Unplanned sampling also occurred and is reported herein. The full protocol was 

conducted at F1 on a second consecutive day providing repeat measures. A reduced set of 

samples (without integrated air particle monitoring) was completed at a third synthetic turf field 

site consisting of two collocated fields (F2 and F3). Some samples were collected for two 

additional turf fields (F5 and F6) collocated with F4. Two F4 “on field” sampling locations were 

very near a busy commuter road and parking deck. 

When a site consisted of multiple fields, one field was designated as the primary location 

for implementing the protocol. In total, samples were collected for six different synthetic turf 

fields. 

Gaining access to playgrounds was very difficult and became even more difficult with 

increased media attention. The full sampling protocol was completed at only one playground 

(P1) and at only two “on playground” sampling locations because of space limitations. Tire 

crumb material molded to mimic wood bark was obtained from a second playground site (P2). 

Sample Collection and Analysis Methods 

Air VOCs. Grab air VOC samples (6-L Summa-polished stainless steel canisters) were 

collected at each sampling location at a 1-m inlet height during the hottest time of day 

(~2:00 p.m.). The standard EPA Method TO-15 gas chromatography/mass spectrometry 

(GC/MS) analytical method provided ambient-level concentration measurements for 56 VOC 

analytes. 

Air Particulate Matter. Two integrated air PM10 samples (one for particle mass and 

metals analysis and another for scanning electron microscopy [SEM] analysis) were collected at 

each sampling location at a 1-m inlet height over collection periods ranging from 5.8 to 7.8 h. 

This resulted in individual sample air volumes ranging from approximately 7.0 to 9.2 m3

 (3.5 to 

5.0 m3

 for SEM samples). PM10 mass was determined gravimetrically; metal concentrations by 

X-ray fluorescence; and assessment of particle size and morphology and attempts to identify 

the tire crumb component contribution by SEM. 

Synthetic Turf Field Surface Wipes. No known validated methods exist for 

characterizing environmental concentrations of metals on synthetic turf surfaces comprised of 

both turf blades and tire crumb rubber. A standard wet-wipe method (American Society for 

Testing and Materials [ASTM] E1728-03) used routinely to measure residential surface dust Pb 

levels was used for this study. Advantages of this method were the availability of standard wipe 

material and the existing, well-characterized, sampling and analytical methodologies. Samples 

were collected at each “on field” turf field sampling location. Wipe samples were not collected at 

the “on playground” or background sampling locations. Each surface wipe, tire crumb, and turf 

blade sample (described below) was extracted first using the EPA In Vitro Relative 

Bioaccessibility Assessment Method 9200.1-86. (Note: In vitro methods measure the 

bioaccessibility [e.g., solubility] of metals during a simulated gastric extraction process to assess 

the percentage of a metal in a material that may become available for absorption in the gastroxiii
intestinal [GI] tract.) The same material from each sample then was extracted using EPA 

Method 3050B. A total extractable concentration of Pb, Cr, Zn, arsenic (As), aluminum (Al), 

barium (Ba), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), and nickel (Ni) was 

determined by an analysis of the combined bioaccessibility and Method 3050B extracts. 

Extracts were analyzed by inductively coupled plasma (ICP)/MS using EPA Method 6020A. The 

percent bioaccessible Pb was calculated from the relative amount in the bioaccessible extract 

as compared with the total extractable amount.

Synthetic Turf Field Tire Crumb Infill. Tire rubber infill was collected randomly at the 

synthetic turf fields. In this study, it was decided to collect infill material that was readily 

available at the surface rather than dislodging material trapped deep within the turf blades. This 

decision was based partly on avoiding potential damage to field components but primarily 

because the material on the surface was more available for potential human contact. Infill 

material was not available uniformly across the field surface. 

Synthetic Turf Field Blades. Blades were randomly collected at the synthetic turf fields. 

Collecting blades of each color present at the field was attempted. Turf blade collection relied on 

the availability of loose blades found on the field surface in lieu of a destructive (i.e., cutting) 

method. Collection and analysis decisions were complicated by the limited availability of loose 

blades and a later determination that a minimum of 0.7 g of material was required for analysis. 

Playground Tire Crumb Rubber. Tire crumb samples were obtained from two 

playground sites. It was not clear how many pieces needed to be collected nor at what depth 

(surface/subsurface) for site characterization, as the crumb shifts with mechanical action. A 

further challenge is that relatively small amounts (1 g or less) are required for analysis; large 

amounts may overwhelm the digestion and analytical systems. Intact tire crumb rubber pieces 

were larger than 1 g. A decision was made not to cut samples, as this would expose 

unweathered surfaces and possibly impact the bioaccessible Pb estimate. 

Conclusions 

The key study findings are summarized below. The narrative and appendixes that follow 

this Executive Summary provide additional details regarding the study, along with all of the 

measurement and laboratory data. This descriptive report focuses on the study design and 

methodologies; assessing the methodology for characterizing environmental concentrations of 

tire crumb constituents in future studies; describing the quality of the scoping study data; and 

providing recommendations for consideration in the design of any future research, if needed. 

In general, the study protocol is expected to reliably yield data for assessing environmental 

concentrations of selected tire crumb constituents and understanding potential exposure routes 

and pathways. However, when considering future study designs and implementation, the 

research needs to carefully consider issues associated with identifying and gaining site access, 

the cost benefit of obtaining the data versus the resource burden, and the implementation of 

other methods for generating data to address specific research hypotheses. Future studies will 

need a carefully developed and implemented communications plan to promote the value of the 

research and gain access to the required facilities. 

(1) The study protocol and many of the methods were found to be reliable and could be 

implemented in the field. Several limitations are noted as follows. 

• Collecting integrated air samples provided a high burden in terms of time and equipment. 

• SVOCs were not measured. 

• At any single site, there can be substantial variability in the materials used and the 

concentrations of contaminants measured. More work is needed to determine where to 

collect samples and how many samples to collect to fully characterize a given site. 

xiv
• It was difficult to obtain access and permission to sample at playgrounds and recreational 

fields. More work is needed to increase public and private owner participation if these 

studies are to be implemented. 

(2) Methods used to measure air concentrations of PM10 and metals were found to be reliable. 

• Concentrations of PM10 and metals (including Pb) measured in air above the turf fields 

were similar to background concentrations. 

• Concentrations of PM10 and metals at the playground site with high play activity were 

higher than background levels. 

• All PM10 air concentrations were well below the National Ambient Air Quality Standards 

(NAAQS) for PM10 (150 μg/m3

). All air concentrations for Pb were well below the NAAQS 

for Pb (150 ng/m3

). 

(3) Methods used to measure VOCs in air were found to be reliable. 

• All VOCs were measured at extremely low concentrations that are typical of ambient air 

concentrations. 

• One VOC associated with tire crumb materials (methyl isobutyl ketone) was detected in 

the samples collected on one synthetic turf field but was not detected in the corresponding 

background sample. 

(4) Methods used to measure extractable metals from turf field blades, tire crumb materials, and 

turf field wipe samples were found to be reliable. However, the aggressive acid extraction 

procedure likely will overestimate the concentration of metals that are readily available for 

human uptake. Because understanding uptake is a key component in understanding risk, 

methods to determine bioavailable metal concentrations are still needed. 

• Total extractable metal concentrations from the infill, turf blade samples, and tire crumb 

material were variable both between sites and at the same sites. 

• The average extractable lead concentrations for turf blade, tire crumb infill, and tire crumb 

rubber were low. Although there are no standards for Pb in recycled tire material or 

synthetic turf, average concentrations were well below the EPA standard for lead in soil 

(400 ppm). 

• Likewise the average extractable Pb concentrations for turf field wipe samples were low. 

Although there are no directly comparable standards, average concentrations were well 

below the EPA standard for lead in residential floor dust (40 μg/ft2

). 

(5) On average, concentrations of components monitored in this study were below levels of 

concern; however, given the very limited nature of this study (i.e., limited number of 

components monitored, samples sites, and samples taken at each site) and the wide 

diversity of tire crumb material, it is not possible to reach any more comprehensive 

conclusions without the consideration of additional data. 

xv
xvi
1. Introduction

1.1 Background 

Tire crumb or crumb rubber is produced from scrap tires or from the tire retreading 

process. During the recycling process, steel and usually fiber are removed, and the remaining 

rubber material is processed either by mechanical means or through freeze cracking into “chips” 

or into various sizes of rubber mesh with a granular consistency. Tire crumb is used in several 

commercial applications, including road construction, sidewalks, automobile parts, and in a 

number of athletic and recreational applications. Recreational uses include ground cover (chips) 

under playground equipment, landscaping mulch (chips), running track material (granular or 

molded), and filler material used with many synthetic turf sports and playing fields (granular). 

The use of tire crumb materials for playground and turf fields provides numerous 

benefits. First, it cushions falls, reducing sports injuries when compared with other playground 

or athletic surfaces. Second, synthetic turf is a low-maintenance alternative to natural grass, as 

there is no or reduced need for water, fertilizers, or pesticides. Because turf fields are installed 

with below-ground drainage systems, there is reduced waiting time after storms, which 

promotes their use. Third, reusing expended tires reduces their potential as disease vectors 

(e.g., water hosting mosquitoes) and reduces the burden on landfills. 

There have been increased reports in the media of parents becoming alarmed when 

their children returned home with tire crumb particles or fragments adhering to their socks and 

clothing picked up while playing on tire-crumb-surfaced playgrounds and turf fields. The U.S. 

Environmental Protection Agency (EPA) Region 8 asked several EPA program offices to help 

understand the extent of crumb rubber recreational uses, fill critical data gaps, and assess the 

available data to determine if there was any unreasonable exposure or risk, particularly to 

children. In response to this request, an Agency-wide workgroup was formed to assess the 

existing information and determine whether the Agency needed to collect additional information. 

The workgroup included representatives from the various program, policy, scientific, and 

communications staff, including the Office of Children’s Health Protection and Environmental 

Education (co-lead), the Office of Pollution Prevention and Toxic Substances, the Office of Solid 

Waste and Emergency Response, the Office of Research and Development (ORD; co-lead), 

and several EPA regional offices. The workgroup requested that a smaller science workgroup 

familiar with planning and conducting environmental field studies be formed to consider the 

quality of the current science and make recommendations regarding the need for future 

research, if any is needed. 

 This scoping study was proposed, designed, and recommended by the science 

workgroup as a means for evaluating readily available methods and to generate consistently 

collected U.S. data that could be used to help inform decisions regarding possible next steps to 

address questions from the public regarding the safety of tire crumb infill used in ball fields and 

playgrounds. This study was not intended to address the very large number of variables that 

might impact environmental concentrations or potential exposures (e.g., manufacturers, 

materials, installation practices, spatial/temporal differences, age, use). The limited study data 

were intended to complement data collected or planned for collection by other State and 

Federal agencies. Although this study included collection and analysis of environmental 

samples that may be associated with several synthetic turf components, the focus of EPA’s 

work is developing and evaluating methods for characterizing tire crumb constituents. Analysis 

of the other components was included to better understand the relative portion of any observed 

tire crumb constituent environmental levels measured in the various samples. This study may 

complement research performed by the Consumer Product Safety Commission (CPSC); the 

States of California, New Jersey, New York, and Connecticut; and New York City regarding 

synthetic turf, but is distinct from the other studies in that the focus is on the tire crumb material. 

1
2

Prior to preparing for a scoping study, a search of the scientific literature revealed limited 

environmental or exposure measurement data associated with the use of tire crumb rubber for 

U.S. recreational fields. Only a few peer reviewed laboratory or environmental studies were 

reported, with many of these studies conducted in Europe. 

Although the results were limited, the search identified a number of compounds and 

metals that may be found in tires, although not all of these compounds and metals are 

contained in every tire nor are they contained in the same concentration in any tire at any given 

time. These compounds and metals include those that follow.

Acetone 

Aniline 

Benzene 

Benzothiazole 

Chloroethane 

Halogenated flame 

 retardants 

Isoprene 

Methyl ethyl ketone 

Methyl isobutyl ketone 

Naphthalene 

Phenol 

Polycyclic aromatic 

 hydrocarbons 

Styrene-butadiene 

Toluene 

Trichloroethylene 

Arsenic 

Barium 

Cadmium 

Chromium 

Cobalt 

Copper 

Lead 

Manganese 

Mercury 

Nickel 

Sulfur 

Zinc 

Pigments 

Nylon 

Polyester 

Rayon 

Latex

1.2 Exposure Science Questions 

A series of general science questions was considered before the study protocol was 

developed; they include the following ones. 

• Can existing collection and analysis approaches and methods be used to assess 

environmental concentrations of tire crumb rubber constituents at synthetic turf fields and 

playgrounds? 

• How well do such methods perform under real-world conditions? 

• Do the methods produce data of sufficient quality to characterize potential exposure routes 

and pathways? 

• Do the methods produce data of sufficient quality to characterize the contribution of 

constituents to various sources? 

• Are the data and information produced through this research, when included with data from 

other studies, useful for developing hypotheses and informing the design of future research, if 

needed? 

• What new methods are needed to fully characterize tire crumb environmental concentrations 

and to understand potential exposure routes and pathways? 

1.3 Project Objectives 

The science workgroup planned a very limited scoping-level field measurement study 

during the 2008 summer/fall season to 

• evaluate, through real-world measurements, the application of readily available sampling and 

analysis methods for characterizing environmental concentrations of selected tire crumb 

contaminants in and around playgrounds and synthetic turf fields; 

• evaluate the overall study protocol (monitoring, analytical, and QC procedures) for generating 

the quantity and quality of environmental measurement data needed to characterize the 

contribution of the tire crumb constituents to environmental concentrations; 

• generate a limited set of consistently collected field measurement data from a few 

playgrounds and synthetic turf fields that, along with other study data, may be used to 
develop insights regarding the importance of the various exposure routes and pathways and 

inform the decision regarding future research, if any is needed; and 

• understand the factors influencing the development and implementation of future study 

protocols. 

1.4 Study Limitations 

This study was designed as a limited scoping-level methods evaluation study. It was 

planned based on readily available resources (personnel, equipment, media, etc.) and in 

consideration of the workgroup’s desired study time period, the 2008 summer and early fall 

months when high ambient temperatures should result in conditions promoting the greatest 

potential for release of tire-related constituents. The study collected limited environmental data 

to help understand and assess methods for characterizing potential route and pathway-specific 

exposures (inhalation, ingestion, and dermal) based on selected sentinel species. This study 

and the resulting data have many limitations, which are described below. 

• The study was not designed to provide representative U.S. environmental measurement data 

for all tire crumb constituents or applications, nor to make conclusions regarding differences 

in environmental concentrations or potential U.S. exposures to field and playground tire 

crumb constituents based on geographical location, type of recreational field, manufacturing 

materials, age, use, or conditions. Resource constraints prohibited the survey, coordination, 

and random selection of U.S. playgrounds and turf fields and the use of the study data in 

supporting statistical analysis or making statistical inferences. The study results can be used 

only to describe the playgrounds and turf fields monitored. 

• The number of samples collected at each site was relatively small and will not necessarily 

support the spatial characterization of the species concentrations across the monitored area. 

• Sampling was planned to be conducted only on one day. Therefore, temporal characterization 

of the targeted environmental contaminants will not be supported. 

• No personal exposure data or related information were collected. 

• No scripted activities were planned or conducted. The study results were dependent on 

normal activity levels by the individuals using the playground or turf field. However, the limited 

data collected in this study likely will not be useful in characterizing differences associated 

with these factors. 

• The study did not evaluate methods for all the reported tire crumb constituents. Sampling and 

analysis of semivolatile organic compounds (SVOCs; e.g., benzothiazole, aniline, polycyclic 

aromatic hydrocarbons [PAHs]), reported in many studies, were not performed because of 

resource limitations. 

• Validated sampling approaches and analysis methods were not available for real-world 

playground and synthetic turf field conditions. Currently accepted methods for measurement 

and analysis of the targeted species in indoor and outdoor microenvironments and in soils 

were used, with modifications required in some cases.

• QC/QA activities were implemented to document the quality of the sampling and analysis 

measurements; however, suitable QA/QC materials and standards were not available for 

some of the types of samples.

3
2. Conclusions and Recommendations 

The following narrative provides key highlights regarding the approach and methods that 

were applied and assessed in this scoping study. The study results are being provided to the 

workgroup for assessment and interpretation. 

2.1 Implementation of the Study Protocol 

• A small scoping-level study protocol was fully implemented at two synthetic turf fields and one 

playground. The protocol was successfully implemented at one of these fields on a second 

day, providing a set of unplanned consecutive day data. Additional data were collected from 

four turf fields and for tire crumb from a second playground. 

• The study’s success reflects the excellent collaborations and contributions of scientists and 

staff across many program offices, regions, States, and ORD. 

• The protocol, and a majority of the corresponding methods employed in this study, generated 

quantitative data that can be used to characterize the contribution of tire crumb constituents to 

the environmental concentrations measured at the synthetic turf field, playground, and 

background sampling locations. 

• Although none of the methods have been validated for this specific application, most methods 

were able to provide measurement data of known quality and at concentrations adequate for 

assessing potential tire crumb constituents. 

• Air particle collection required considerable time, equipment, and expertise. 

• Other collection procedures (air volatile organic compounds [VOCs]), wipe, and material 

collection) required much less time, equipment, and expertise. 

• In general, the study protocol can be implemented and will yield data for assessing 

environmental concentrations and potential exposures for tire crumb constituents for various 

routes and pathways. However, when considering the design and implementation of future 

studies, the research needs to carefully consider 

- issues associated with identifying and gaining site access, 

- the value of the data being generated versus the resource burden, and 

- the implementation of other methods for generating data to address specific research 

hypotheses. 

• Any future study will need a corresponding carefully developed and implemented 

communications plan to help promote the value of the research and gain access to the 

required facilities. 

2.2 Air Sampling and Analysis

• The air sample collection and analysis methods provided data suitable (both quality and 

concentration levels) for assessing environmental levels of particles, metals, and VOCs in air. 

• Air particulate matter sampling employing relatively large (carry-on-size suitcase), batteryoperated pumps and size selective inlets yielded sufficient particle mass for measuring 

selected metals at commonly reported ambient air levels. This sampling approach required 

significant resources (equipment and experienced field staff) and long setup and sampling 

durations (8 to 10 h). 

• Collecting air VOCs via grab sampling during the hottest daytime period (conditions when the 

greatest emissions from tire crumb material were anticipated) was simple and required little 

time (~1 h). 

• The air VOCs methods generated concentration data for many compounds. Slightly elevated 

MIBK levels were found at one turf field. The reproducibility in the data approximates what 

previously has been reported in other field measurement studies. The use of an integrated 

4
sampling pump method likely would increase the number of species with reportable data but 

would not necessarily generate substantially different data for characterizing tire crumb 

source contributions, environmental concentrations, or potential exposures. 

• The air particulate matter (PM) mass and metals methods yielded reproducible results, with 

the turf field concentrations approximating the background levels. Concentrations on one 

playground site were somewhat higher than the background concentration. 

• Tire crumb related fibers were not observed in the air samples analyzed by scanning electron 

microscopy (SEM). The SEM data were not sufficient for source apportionment or attribution 

of the data to any tire crumb constituent because of the variability of compositional or 

morphological characteristics of particles associated with the tire crumb material collected in 

this study. 

2.3 Surface Wipe, Tire Crumb, and Turf Blade Sampling and Analysis

• No evaluated method was available for assessing dermal and indirect ingestion from tire 

crumb constituents in turf field or playground surfaces. A standard surface wet wipe sample 

collection method for residential lead (Pb) measurement was used at the synthetic turf fields. 

This method performed reasonably well for assessing extractable metals and required modest 

skills and time (~1 h). 

• Collection of tire crumb infill and turf blade material at synthetic turf fields and tire crumb at 

playgrounds was straightforward, requiring minimal skills and resources (~1 h). Convenience 

samples were collected in this study based on the materials being readily available on the 

surface. There is evidence that the material is not homogeneous with regard to some 

constituents (Pb for example). Future site characterization studies should be considered to 

evaluate the issue of sample heterogeneity and the impact on data interpretation. 

• Wipe, tire crumb, and turf blade samples were extracted using EPA Method 9200.1-86 for in 

vitro Pb bioaccessibility and EPA Method 3050B for total extractable Pb (and other metals). 

Both extraction techniques were combined with EPA inductively coupled plasma (ICP)/MS 

Method 6020A. These methods require extensive skill and resources. Multiple analyses of 

sample extracts with varying dilutions were required to capture the range of elements and 

concentrations within appropriate calibration parameters. 

• The in vitro Pb bioaccessibility method was judged not appropriate for the surface wipe 

samples. Because the in vitro method has been validated only for soil samples, additional 

validation studies would be required to fully demonstrate the relevance of the method for tire 

crumb and turf blade materials. 

• Although the methods appeared to perform reasonably well, a number of sample handling, 

size, and heterogeneity issues were discovered that may affect method performance and data 

interpretation. 

• There is a lack of appropriate QC/QA materials and spiking methods. QA/QC materials and 

procedures need further development for the methods as applied to these materials. 

• The wipe, tire crumb, and turf blade data identified a potentially significant variability in source 

contribution based on turf field blade color and type, along with the tire crumb fraction being 

analyzed. Additional research is needed to understand the factors influencing the reported 

variability before future studies are designed and conducted. Understanding the variability is 

important in developing improved approaches for site characterization. 

2.4 Conclusions with Regard to the Exposure Science Questions

• Can existing collection and analysis approaches and methods be used to assess 

environmental concentrations of tire crumb rubber constituents at synthetic turf fields and 

playgrounds? Yes, existing air sampling and analysis methods can be used. Existing methods 

5
for analysis of metals in synthetic turf field and playground components can be successfully 

applied, but may require additional validation assessments. 

• How well do such methods perform under real-world conditions? The air sampling and 

analysis methods evaluated performed well. Methods for analysis of metals in synthetic turf 

field and playground components showed good precision, but the assessment of recovery for 

some metals was difficult because of the nonhomogeneity of the bulk materials. 

• Do the methods produce data of sufficient quality to characterize potential exposure routes 

and pathways? In most cases, the methods appeared to produce data of sufficient quality with 

regard to sensitivity, precision, and accuracy. Additional validation efforts may be needed to 

interpret measurement results, particularly with regard to bioaccessibility of metals in 

synthetic turf field and playground components. 

• Do the methods produce data of sufficient quality to characterize the contribution of 

constituents to various sources? Some of the methods generated data of sufficient quantity 

and quality. Research is needed to better understand relative source contributions, in 

particular for the wipe and air particle samples. 

• Are the data and information produced useful, when included with data from other studies, for 

developing hypotheses and informing the design of future research, if needed? The 

assessment of approaches and methods tested in this scoping study, in combination with 

research recently completed and ongoing by other organizations, will be very useful for 

developing hypotheses and informing the design of future research, if needed. 

• What new methods are needed to fully characterize tire crumb environmental concentrations 

and to understanding potential exposure routes and pathways? Testing and application of 

personal sampling methods would provide a more complete understanding of how 

environmental concentrations translate into potential exposures. Methods for collection and 

analysis of SVOCs were not tested in this scoping study but would be needed for a full 

characterization. 

6
3. Scoping Study Approach 

3.1 Scoping Study Goals 

The primary goal of this scoping study was to evaluate readily available methods and 

approaches for characterizing environmentally available concentrations of selected 

contaminants at synthetic turf fields and playgrounds that include tire crumb material. There are 

currently no known validated sampling and analysis methods for these types of installations and 

materials. Integrated and/or grab air, wipe, and material sample collection and analysis methods 

(Table 1) were selected based on professional evaluation. Where available, standard methods 

used routinely to characterize the targeted environmental contaminants in other 

microenvironments were selected. However, because of time and resource constraints, none of 

these methods were evaluated for the intended study application. A list of the sample collection 

and analysis methods used or developed for this study is provided in Appendix A. The detailed 

methods were included in the approved study QA project plan. 

A number of constraints influenced the decisions on proposed methodologies. These 

included limited resources (e.g., time, people); an anticipated lack of readily available electrical 

power at the sites; uncertainty in sample collection times because of site availability or activity 

issues; the need for equipment that can be shipped to multiple sites across the country; and the 

need for rugged, simple methods that could be implemented consistently by minimally trained 

technical staff at several sites. 

3.2 Organizations 

The scoping study approach was developed based on the cross-Agency collaborative 

effort outlined below. 

• National Exposure Research Laboratory (NERL): Prepare and ship sample collection 

equipment and media (less VOCs [see below]). Provide technical support for measurements. 

Analyze air filter media for mass, metals, and morphology. Analyze tire crumb material, turf 

blade material, and surface wipes for metals. 

• EPA Regions 4, 5, and 9: Identify, assess, and coordinate access to the study sites. 

Communicate study to the public. 

• EPA Region 1: Prepare VOC sampling media (canisters) and conduct TO-15 analyses. 

• Workgroup: Assessment and interpretation of the study data provided in this report in context 

with other research data and Agency compliance guidelines following receipt of this report. 

3.3 Selection of Target Analytes 

Target analytes in this study were selected based on a combination of three factors: 

(1) chemicals that have been associated with tire material (see Section 1.1); (2) chemicals that 

have been reported in other measurement studies at synthetic turf fields or playgrounds or are 

of interest for these types of facilities; and (3) chemicals that could be analyzed using the 

methods and resources that were readily available for this study. Methyl isobutyl ketone (MIBK) 

was selected as a potential marker for emissions of volatile tire components into the air. PM10

was selected because it may occur from physical degradation of tire crumb material and its 

potential for activity-related suspension into the air. PM10 particles are of interest because they 

may be inhaled and also swallowed following trapping by mucus membranes. The metals Pb 

and chromium (Cr) were of interest both because of their potential presence in tire material, and 

also because they have been shown to be associated with pigments used in some types of 

synthetic turf blades. 

The metal zinc (Zn) was of interest as a potential marker for tire crumb material. Other metals 

were of secondary interest because of their potential association with tire material or because 

they can provide additional particle source information. In some cases, additional VOC or metal 

7
Table 1. Summary of Sample Collection and Analysis Methods

Sample Type Sites Sampling Method Analytical Method Target Analytes 

Air Particulate 

Matter (PM10―

particles with 

aerodynamic 

size <10 μm) 

Synthetic 

turf fields 

Playgrounds 

ORD/NERL Research 

Protocol 

SKC pump, gel-cell 

battery, Harvard 

10-μm impactor, 

37-mm Teflon filter, 

20-L/min flow rate 

1-m sampling height, 

three sites on/near 

playground/field, one 

site for background 

ORD/NERL Research 

Protocol 

Gravimetric analysis 

PM10 mass 

Air Metals in 

PM10

Synthetic 

turf fields 

Playgrounds 

Same sample as 

collected for PM10 

mass. 

ORD/NERL Research 

Protocol 

XRF (X-ray fluorescence) 

Primary: 

Pb, Cr, Zn 

Secondary: 

Ca, Cl, Cu, Fe, 

K, Mn, S, Si, Ti 

Air Particles/ 

Fibers for 

Scanning 

Electron 

Microscopy 

(SEM) 

Synthetic 

turf fields 

Playgrounds 

ORD/NERL Research 

Protocol 

SKC pump, gel-cell 

battery, Harvard 

10-μm impactor, 

polycarbonate filter, 

10 L/min 

Same sites and 

height as PM10

ORD/NERL Research 

Protocol 

SEM (scanning electron 

microscopy) 

Particle 

morphology 

Particle size 

distribution 

Attempt to 

characterize tire 

crumb 

composition 

signature 

Air Volatile 

Organic 

Compounds 

(VOCs) 

Synthetic 

turf fields 

Playgrounds 

Method TO-15 

6-L Summa canisters 

Grab sample 

collected at approx. 

2:00 pm, or hottest 

time of day when 

access to the field is 

possible. 

1-m sampling height, 

three sites “on 

playground/field”, one 

site for background 

TO-15 GC/MS (gas 

chromatography/mass 

spectrometry) 

Primary: 

Methyl-isobutylketone 

Secondary: 

55 other alkane, 

aromatic, 

oxygenated, and 

halogenated 

compounds 

8
Table 1. Summary of Sample Collection and Analysis Methods (cont’d.)

Sample Type Sites Sampling Method Analytical Method Target Analytes 

Surface Wipe Synthetic 

turf fields 

ASTM E1792 wipes 

(Ghost Wipes) and 

ASTM E1728 dust 

collection method. 

This is a standard wet 

wipe method. 

Collect wipes from 

three 1-ft2 sites on turf 

fields. 

Wipes placed in 

precleaned 50-mL 

polyethylene 

container. 

Collect a second 

sample wipe next to 

each original 

sampling location for 

archival or possible 

metals bioavailability 

analysis 

EPA Method 3050B, acid 

digestion with 

determination by EPA 

Method 6020A (ICP/MS 

inductively coupled 

plasma mass 

spectrometry) 

RBALP in vitro extraction 

(EPA Method 9200.1-86) 

for bioaccessible lead, 

and determination using 

ICP/MS by EPA Method 

6020A 

Primary: 

Pb, Cr, Zn 

Secondary: 

Al, As, Ba, Cd, 

Cu, Fe, Mn, Ni 

Pb 

Tire Crumb 

Material 

(crumbs from 

playgrounds 

and infill 

material from 

synthetic turf 

fields) 

Synthetic 

turf fields 

Playgrounds 

ORD/NERL Research 

Protocol 

Collect samples of 

crumb material from 

three sampling 

locations on each 

playground or field. 

Add material to clean 

HDPE bottle. 

Collect a second set 

of samples for 

archival for possible 

metals bioavailability 

analysis or SVOC 

analysis. 

EPA Method 3050B, acid 

digestion, and 

determination by EPA 

Method 6020A (ICP/MS) 

RBALP in vitro extraction 

(EPA Method 9200.1-86) 

for bioaccessible lead, 

and determination using 

ICP/MS by EPA Method 

6020A 

Primary: 

Pb, Cr, Zn 

Secondary: 

Al, As, Ba, Cd, 

Cu, Fe, Mn, Ni 

Pb 

9
Table 1. Summary of Sample Collection and Analysis Methods (cont’d.)

Sample Type Sites Sampling Method Analytical Method Target Analytes 

Turf Blades Synthetic 

turf fields 

ORD/NERL Research 

Protocol 

Collect loose blades 

from field surface in 

several sampling 

locations on the field, 

collect samples of 

different colors where 

possible, place blades 

in a clean 

50-mL polyethylene 

container. 

Where there is 

sufficient material, 

archive material for 

possible metals 

bioavailability 

analysis. 

EPA Method 3050B, acid 

digestion, and 

determination by EPA 

Method 6020A (ICP/MS) 

RBALP in vitro extraction 

(EPA Method 9200.1-86) 

for bioaccessible Pb, and 

determination using 

ICP/MS by EPA Method 

6020A 

Primary: 

Pb, Cr, Zn 

Secondary: 

Al, As, Ba, Cd, 

Cu, Fe, Mn, Ni 

Pb 

analytes were included because they could be measured as part of the routine analysis of 

analytes of higher interest. As noted earlier, semivolatile chemicals, such as benzothiazole and 

PAHs, were of interest but were not measured in this scoping study because of the lack of 

readily available resources. 

3.4 Proposed Sampling Sites and Sampling Locations 

A study goal was to collect real-world environmental samples in four geographical areas 

across the United States (located near the four NERL laboratory locations) in late summer and 

fall of 2008: 

• Athens, GA (EPA Region 4), 

• Research Triangle Park, NC (EPA Region 4), 

• Cincinnati, OH (EPA Region 5), and 

• Las Vegas, NV (EPA Region 9). 

The recommended approach relied on available NERL technical staff to implement the 

sampling protocol and the use of the laboratories’ facilities as staging areas. In each 

geographical region, two sampling sites were to be defined: (1) a playground with crumb rubber 

material and (2) a synthetic turf field with tire crumb rubber infill. The proposed design would 

result in sampling at four playground sites and four synthetic turf field sites. Based on availability 

and access, alternate approaches were to be considered regarding the number of sites to be 

monitored in an area. 

At a given sampling site (turf field or playground), four sampling locations were to be 

selected: three “on field” sampling locations and a background sampling location. The proposed 

“on field” sampling location configuration was an isosceles triangle, with one sampling location 

near the center of the playground or field and the other two at approximately equally distanced 

downwind positions. Actual deployment configuration was dependent on the site layout, planned 

activities, and wind direction. The background sampling location was intended to be within 

100 m of the field or playground, over a natural grass surface when possible, and not in close 

proximity to likely pollutant sources. At each of the four sampling locations, all the following 

environmental samples and measures were to be collected (nominal, except where noted): 

10
• integrated air PM10 sample for particle mass and metals composition, 

• integrated air PM10 sample for particle morphology (size and shape), 

• grab air sample for VOCs, 

• wet wipe for metals composition (not at the background sampling location), and 

• materials (tire crumb and turf fibers). 

All air sampling was to be conducted with the inlet at a height of 1 m. Additional 

duplicate samples and measures were collected at one sampling location at each site. Standard 

meteorological measures (temperature, relative humidity [RH], and wind speed and direction) 

were taken periodically at each site sampling location. Activity levels (e.g., number of activities, 

number of individuals, type of activity) also were recorded. A 1-m2

 square plastic child barrier 

was set up around each sampling location to prevent the participants from running into or falling 

on the sampling equipment. 

3.5 Sampling Considerations 

There is no standard approach for determining the number of sample collection locations 

or the timing of sample collection at any one playground or synthetic turf field site. Key factors 

that were considered included 

• potential variability of materials and chemical concentrations within a site; 

• potential variability of activities at a site over time; 

• meteorological conditions, particularly moisture, temperature, and wind speed and direction; 

and 

• contribution of ambient background levels or nearby source contribution of the targeted 

chemicals to onsite measurements. 

Each key factor is briefly described below, along with the proposed approach taken to minimize 

or characterize the impact on the resulting data. 

3.5.1 Material Variability 

 Factor: Materials and chemical concentrations could vary within a site resulting in 

variation of targeted species across space and time at the playground or turf field. However, few 

data were available regarding the variability in contaminant concentrations within a playground 

or synthetic turf field site. Also, there was little information available to guide optimum locations 

for sampling at a site. 

Proposed Approach: Three sampling locations were selected within the boundaries of 

the playground or turf field in areas close to the anticipated activity. These sampling locations 

were positioned such as to not interfere with normal activity or use. An additional background 

sampling location was selected near (~20 to 100 m) and upwind from the playground or turf field 

to characterize ambient background levels. This approach was implemented successfully for air 

samples with the exception that only two “on playground” sampling locations were set up at the 

playground because of the small size of the area. In addition, the tire crumb infill material and 

synthetic turf blades were collected where available, rather than at predetermined locations. 

3.5.2 Activity Variability 

 Factor: Activities could vary over time at a site. Activity levels for the sites and sample 

collection locations could be highly variable within and between sites. This study was a scoping 

environmental measurement and methods development study. Therefore, no scripted activities 

and no personal measurements were implemented. Activity levels may affect air particle 

measurements. However, activity levels are unlikely to affect air VOC measurements, surface 

wipes, and tire crumb and turf blade material grab sampling. The normal use or activities at one 

site might require one or more of the samplers to be deployed near but not directly on the 

11
playground or turf field. In this case, the samplers were placed as close to the activity as 

permitted. 

3.5.3 Sample Volume for Detection Limit 

Adequate sample volumes are needed to obtain reasonable detection limits for airborne 

particles and metals on particles. Therefore, equipment and methods for particle air sampling 

were selected to provide flow rates of 20 L/min over a nominal 8-h sample collection period. If 

the particle air sampling duration was applied to match an ongoing site activity of less than 8 h, 

then detection limits for those samples would be higher. A minimum sample collection time of 

2 h for air particle samples was selected. 

Proposed Approach: Where practical and permitted, air particle samples were collected 

in close proximity to where activities were ongoing, but without interfering with the normal 

activities or use of the playground or turf field. Information about extant activities at each site 

was collected. This approach was implemented successfully. 

3.5.4 Meteorological Conditions 

 Factor: Meteorological conditions, particularly moisture, temperature, and wind speed 

and direction, might impact sample collection decisions and potential emissions. Meteorological 

conditions may influence air particle and air VOC measurements at playground and turf field 

sites. Wind will transport airborne pollutant species away from the site and will transport ambient 

pollutant species onto the site. Suspension and resuspension of particles likely will be affected 

by meteorological conditions. Temperature likely will influence the VOCs that might be emitted 

from tire crumb or other synthetic turf materials. With higher temperatures, higher levels of 

VOCs emissions would be anticipated. 

Proposed Approach: This study was designed to collect air samples during those 

meteorological conditions that likely would result in the highest emissions (i.e., hot, dry, and 

calm days). Sampling was scheduled in August and September on days when no rain had 

occurred on the previous day and when no rain was anticipated, with anticipated wind speeds 

<10 mph. Air VOC samples were collected during the hottest time of day (~2 p.m.) at each “on 

field” or “on playground” sampling location at the site. Air sampling locations were selected, 

where possible, to offset potential changes in wind direction. Portable meteorological 

measurement stations were not deployed. Basic information about meteorological conditions 

(temperature, wind speed, and approximate wind direction) was collected at each site using a 

handheld measurement device. In general, this approach was implemented successfully. 

3.5.5 Background Contribution 

Factor: Ambient background pollutant levels could contribute to onsite measurements, 

particularly for air samples. Ambient contaminants also may contribute to the total burden at the 

playground or turf field as a result of aerosol or dust deposition. 

Proposed Approach: At each playground or synthetic turf field site, one background 

sampling location was collected upwind from the playground or turf field. A set of air samples 

identical to the other sample collection locations was collected at the background sample 

collection location. The resulting data were intended to be used to characterize the potential 

contribution of ambient or background air contaminants to the playground or turf field. This 

approach was implemented successfully. 

12
4. Methods 

4.1 Air VOC Samples 

Grab air samples for VOCs were collected using evacuated 6-L Summa-polished 

stainless steel canisters during the hottest time of day (~2 p.m.). This collection time was 

selected for likely highest air and surface temperature conditions promoting VOC emissions. Air 

temperature and surface temperature were measured and recorded at the time the samples 

were collected. Each sample was collected by opening the canister valve and allowing the 

evacuated canister to fill with air over an interval of approximately 20 s. The canister valve then 

was closed, and the canisters stored at ambient temperature until analysis. The canister 

samples were analyzed at the EPA Region 1 Office of Environmental Measurement and 

Evaluation for 56 VOCs by gas chromatography/mass spectrometry (GC/MS) following EPA 

Method TO-15. 

4.2 Air PM10 Particle Samples for Mass and Metals Concentrations 

PM10 is defined as airborne particulate matter with an aerodynamic size less than 10 

μm. Ambient air was sampled at a nominal flow rate of 20 L/min (LPM) using metered, dir

current-supplied active samplers (SKC-HV-30 air pumps) and Harvard Impactor inlets (Air 

Diagnostic and Engineering), enabling PM

ect10 mass loading on 47-mm Teflo filter media (Williams 

et al., 2008). Air monitoring was initiated for all monitors in quick order on their setup and 

calibration and continued without interruption through the monitoring event (day). At the 

conclusion of the sampling event, filter samples were recovered, stored in sealed transportation 

containers, and returned to the laboratory under ambient temperatures. The sampler ending 

flow rate was checked. 

Filters were returned to the NERL Research Triangle Park, NC, gravimetric weighing 

facility, which operates under Federal Reference guidelines for temperature and relative 

humidity specifications (22 ± 0.5 °C, 35 ± 1% RH). The filters underwent a 24-h equilibration 

period prior to mass loading determination (Chen et al., 2007). Filter mass loadings were 

determined as the difference between presampling (tare) weights and those obtained following 

postsampling using a Sartorius MC 5 microbalance. The differential mass loading and data 

pertaining to the total volume of air sampled through each individual filter then was used to 

calculate the air mass PM10 concentration in units of micrograms per cubic meter for each 

sampling location. Immediately following gravimetric analysis, the PM10 mass concentration 

filters were released to the NERL X-ray fluorescence (XRF) laboratory for metals analysis. 

Metals analysis was performed for 44 selected metals using the NERL’s unique Lawrence 

Berkeley National Laboratory-designed spectrometer (Williams et al., 2008). 

4.3 Air PM10 Particle Sample Collection for Scanning Electron Microscopy 

Sample collection for assessing air particle morphology and selected particle metals 

composition using SEM was conducted similarly to the primary PM10 mass and metals sample 

collection method. Identical SKC HV-30 pumps and similar Harvard Impactor samplers were 

used, the only differences being the operation of the units at a lower flow rate (10 LPM) to 

overcome observed filter pressure drop issues affecting pump battery life and run time. 

Specialized 37-mm polycarbonate filter material (Nuclepore) needed for SEM analyses was 

used. 

4.4 Surface Wipe Sample Collection―Synthetic Turf Fields 

Surface wipe samples were collected at synthetic turf field sites using a wet (water) wipe 

(Environmental Express, Ghost Wipe No. 4210) conforming to American Society for Testing and 

Materials (ASTM) E1792-03 requirements. Samples were collected at times when it was safe to 

13
do so with regard to any activities occurring on the field. Sample collection time was not critical 

for these samples. Two co-located samples were scheduled for collection at the three ”on field” 

sampling locations. No background sampling location wipe sample was collected. Samples 

were collected following the ASTM E1728-03 method, a standard wet-wipe method for collecting 

dust from indoor floor surfaces that used water as the wetting agent. Specifically, a 1-ft2 

template was placed on the surface of the field. Using clean, powderless plastic gloves, the field 

sampling technician removed the wet wipe from the foil packet. Using one side of the wipe, the 

turf surface was wiped in a U-shaped pattern within the template area. After folding the wipe in 

half to get a fresh wipe surface, the area was wiped again in a U-shaped pattern perpendicular 

to the first wipe pattern. The wipe was then folded in half again and the edges near the interior 

portion of the template were wiped. Finally, the wipe was folded again and placed in a 

precleaned 50-mL polyethylene tube (Environmental Express, Disposable Digestion Cup No. 

SC475) for storage. The tube was tightly capped and transported at ambient temperature to the 

laboratory, where the samples were placed in a freezer at -20 °C. 

4.5 Tire Crumb Infill Material Sample Collection―Synthetic Turf Fields 

Tire crumb infill material was collected at the synthetic turf field sites. Samples were 

collected from one or more areas primarily based on availability of infill material (small tire 

crumb granules) at the surface of the field. These sampling locations did not necessarily 

correspond to the air particle sampling sites. Samples were collected at times when it was safe 

to do so with regard to any activities occurring on the field. Sample collection time was not 

critical for these samples. No background sample was collected. Infill material was scooped into 

a precleaned 50-mL polyethylene tube (Environmental Express, Disposable Digestion Cup No. 

SC475) for storage. The tube was tightly capped and transported at ambient temperature to the 

laboratory, where the samples were placed in a freezer at -20 °C. 

4.6 Blade Material Sample Collection―Synthetic Turf Fields 

An attempt was made to collect samples of the loose “grass blades” at synthetic turf field 

sites. No destructive sample collection was allowed, so blades were not cut or harvested from 

the turf fields. Where possible, samples were to be taken for each color of turf blades on the 

field. Sampling locations did not necessarily correspond to the air particle sampling sites. 

Samples were collected at times when it was safe to do so with regard to any activities 

occurring on the field. Sample collection time was not critical for these samples. No background 

sample was collected. Blades were collected using cleaned plastic forceps and were placed into 

a precleaned 50-mL polyethylene tube (Environmental Express, Disposable Digestion Cup No. 

SC475) for storage. The tube was tightly capped and transported at ambient temperature to the 

laboratory, where the samples were placed in a freezer at -20 °C. 

4.7 Tire Crumb Material Sample Collection―Playgrounds 

Two different approaches were used for sample collection at playgrounds. For the first 

approach, sample collection locations were approximately adjacent to the “on playground” 

sampling locations. Sample collection time was not critical for these samples. No background 

sample was collected. Tire crumb material was intended for collection from an approximate 

4” x 4” square, with material collected from the surface down to ground level at each site. 

Material was collected using forceps or another appropriate tool, and crumbs were placed into a 

250- or precleaned 500-mL, high-density polyethylene wide-mouth bottle (SciSpec Scientific 

Specialties Service, Inc, No. 353008 or No. 353016) for storage. The bottle was tightly capped 

and transported at ambient temperature to the laboratory, where the samples were placed in a 

freezer at -20 °C. At the second playground, a simple collection of tire crumb rubber material 

was performed. Samples were placed in polyethylene bags and were mailed to the laboratory. 

14
Once received there, the samples were placed into high-density polyethylene bottles and stored 

in a freezer at -20 °C. 

4.8 SEM Sample Preparation and Analysis 

4.8.1 Sample Preparation 

Ambient samples: 5 mm x 5 mm sections were cut from each polycarbonate filter using a 

stainless steel scalpel. Each section was affixed to a standard 12-mm aluminum specimen stub 

using a double-sided, sticky C tab. The samples were then coated with ~200 Å of C to minimize 

sample charging by the electron beam during SEM analysis. 

Source material samples: Individual crumbs from the bulk material sample, typically 2 to 

3 mm in size, were deposited “as is” on a sticky C tab. Source particles closer in size to the 

ambient sample were generated by shaving pieces from larger crumbs using a stainless steel 

razor blade. Source samples were coated with ~200-Å film of conductive C to minimize charge 

buildup on the sample during SEM analysis. 

4.8.2 SEM Sample Analysis 

Samples were analyzed by SEM and Energy-Dispersive X-ray Spectrometry (EDX) 

using the Personal SEM (R.J. Lee Instruments Ltd.) in the NERL Electron Microscopy 

Laboratory. Manual SEM/EDX analysis was first conducted on the bulk tire crumb source 

samples. Chemistry and morphological features characteristic of the tire crumb material were 

identified to help identify tire crumb particles in the ambient samples. Ambient samples were 

analyzed by computer-controlled SEM (CCSEM/EDX). Instrument parameters for the CCSEM 

analyses included 20-kV accelerating voltage, backscattered electron (BSE) imaging mode, 

16-mm working distance, and zero tilt. The BSE mode yields a more uniform background than 

the secondary electron (SE) mode, necessary for computer-controlled SEM, but at the expense 

of some loss in sensitivity for small carbonaceous particles; carbonaceous tire crumb particles 

about 1 μm or smaller can be difficult to distinguish from the polycarbonate filter substrate in 

CCSEM analyses. Thus, small carbonaceous particles may be underreported in these analyses. 

The CCSEM analysis was set up to analyze particles with average diameters between 

1 and 20 μm. Few particles >10 μm, however, were observed in any sample. All particles within 

this size range were sized automatically and analyzed by EDX for chemistry. Based on the 

analyses of the tire crumb source samples sulfur (S), Zn, and C were identified as possible 

indicators of tire crumb material. Rules were developed to optimize the search for tire-crumb-like 

particles by extending the X-ray analysis time (10 s) and saving low-resolution images for all 

particles containing S, Zn, or C. Images and spectra for these particle types were reviewed 

manually offline, and particles were judged subjectively to be either tire-crumb-like, or not tire 

crumb material based on the particle morphology and chemistry. 

Only a small fraction of the 6.7 cm2

 deposit area of each ambient filter was analyzed by 

CCSEM, typically about 1 mm2

, to complete each analysis in a reasonable time. Following 

CCSEM analyses, the EDX spectra and images of the particles of interest were reviewed 

manually, particles were relocated in the SEM for further examination, and suspected tire crumb 

particles were flagged.

4.9 Surface Wipe, Tire Crumb, and Turf Blade Sample Metals Analysis 

Surface wipe samples, tire infill, tire crumb, and turf blade samples were received and 

prepared for analysis. Detailed sample descriptions were recorded because it was observed 

that the blade, infill, and crumb samples were not homogeneous. The playground tire crumb 

sample pieces were quite large and heavier than the normal sample size used for Pb in vitro 

15
bioaccessibility extractions (typically 1 g). Five turf blade samples were not processed because 

they did not meet the minimum sample size of 0.7 g. 

Sample Selection and Processing. For wipe samples, the entire wipe was used after 

removing any obvious turf blades or pieces of the infill material. For the crumb rubber infill 

samples from synthetic turf fields, 1.0 g aliquots were weighed out after rotating the field 

collection tubes in the x, y, and z axes for 1 min. For synthetic turf blade samples, the samples 

were processed with consideration of blade color. If more than one color of blade was present in 

the sample, representative blades of each color were selected for extraction. For the crumb 

rubber samples from playgrounds, pieces that appeared representative of the entire sample 

were chosen for extraction. In the situation where all pieces were very heavy, the piece closest 

to 1 g was used. A decision was made not to cut the samples as that would introduce fresh 

unaged surfaces, which potentially could impact the Pb bioaccessibility of the sample. Duplicate 

sample aliquots were chosen for extraction and spiking where there were adequate quantities. 

Sample Extraction. The samples were treated as “soil” for the scoping study. Existing 

extraction procedures already in place were used. A consecutive extraction approach was taken 

because of the small number and amount of samples collected in the field. 

First, the Pb in vitro extraction procedure EPA 9200.1-86 May 2008 “Standard Operating 

Procedure for an In Vitro Bioaccessibility Assay for Lead in Soil” was used. Two 10-mL aliquots 

from the 100-mL extract total were removed for analysis and storage. The extracts were 

adjusted to 2% nitric acid (HNO3; v/v) prior to analysis. 

To obtain total leachable metals, SW-846 Method EPA 3050B “Acid Digestion of 

Sediments, Sludges and Soils” was used next. The method was used as written with the 

following minor modifications. 

• After quantitative transfer of the 80 mL of Pb in vitro extract and solids from the in vitro 

extraction bottles to 250-mL glass beakers, 5 mL of concentrated HNO3 was added to the in 

vitro extracts, and the extracts were reduced in volume to 5 mL on a hot plate. 

• A maximum of 2 h of acid refluxing was performed (similar to the hot block option extraction 

time). Neither the tire crumb infill nor tire crumb samples from playgrounds completely 

dissolved. 

• Samples were filtered through a Whatman 25-mm GD/X 0.45-μm cellulose acetate membrane 

syringe filter, as centrifugation was not adequate to separate the particulates from the solution 

for analysis. 

• Final samples extracts for EPA Method 3050B were in 5% HNO3 (v/v). 

Analysis by ICP/MS. A new X-Series II quadrapole ICP/MS was designated as the 

preferred instrument despite it still being in “start-up” mode. Therefore, instrument, software, 

and data processing routines were developed and evaluated concurrent with the samples’ 

analysis. After dilution, the in vitro extracts were 2% HNO3 (v/v). The EPA 3050B extracts were 

received as 5% HNO3 (v/v), and all subsequent dilutions were made by weight with 5% HNO3

(v/v). 

Quantitative analysis for total extractable mass concentration was performed for the 

primary metals of interest: Cr, Pb, and Zn. In addition, the metals aluminum (Al), arsenic (As), 

barium (Ba), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), and nickel (Ni) were 

reported; however, QC assessment was not as extensive for these metals. 

 The instrumental details for the Thermo X-Series ICP/MS are shown in Appendix B as 

follows: Table B-4 lists the operating parameters, Table B-5 lists masses used and interference 

correction information, Table B-6 lists the calibration standards used, and Table B-7 lists 

method detection limits. 

The sample extract analysis followed procedures outlined in EPA SW-846 Method 

6020A (http://www.epa.gov/epawaste/hazard/testmethods/sw846/online/index.htm). Instrument 

performance indicators are the QC solutions listed in Appendix B, Table B-8. For samples that 

16
needed multiple dilutions to insure that all metals of interest were in the calibration range, the 

lowest dilution was used for a metal, where it did not exceed the top standard. Total extractable 

concentrations are calculated from the prorated combination of the in vitro extract 

concentrations and the EPA 3050B extract concentrations. 

4.10 Pb Bioaccessibility Analysis 

4.10.1 In Vitro Bioaccessibility Background Information 

Methods for assessing Pb bioavailability in soil include in vivo animal studies, in vitro 

(referred to as bioaccessibility) studies, and mineralogical/speciation studies. In vivo studies 

quantify the metal present in various tissues and excreta of animals after an animal feeding 

bioassay is conducted. In vitro methodologies are physiologically based extraction tests 

designed to mimic the human gastrointestinal system. In vitro methods measure the 

bioaccessibility (e.g., solubility) of metals during a simulated gastric extraction process. 

Bioavailability for this study is defined in the Guidance for Evaluating the Oral 

Bioavailability of Metals in Soils for Use in Human Health Risk Assessment (OSWER 9285. 

7-80) as “The fraction of an ingested dose that crosses the gastrointestinal epithelium and 

becomes available for distribution to internal target tissues and organs 

(http://www.epa.gov/superfund/bioavailability/guidance.htm).” A related term pertaining to 

bioavailability assessment is bioaccessibility. Bioaccessibility refers to a measure of the 

physiological solubility of the metal at the portal of entry into the body (NRC, 2003). The U.S. 

EPA guidance document describes the methodologies for predicting lead bioavailability in soil 

using either an in vivo swine bioavailability bioassay or an in vitro bioaccessibility assay (IVBA). 

These methods have undergone extensive testing and evaluation, and they “are scientifically 

sound and feasible methodologies for predicting bioavailability of lead in soil” (OSWER 9285. 

7-77). EPA recently published a standard operating procedure (SOP) for an in vitro 

bioaccessibility extraction for Pb that has been validated against the juvenile swine model (EPA 

Method 9200.1-86). The in vivo and in vitro methods described are specific to Pb-contaminated 

soils and Pb bioavailability. Currently, these methods have not been validated for testing other 

contaminants or media (e.g., tire crumb materials), and these have only been validated by EPA 

for Pb in soil. 

4.10.2 In Vitro Pb Bioaccessibility Methodology 

As noted above, validated in vitro methods did not exist for tire crumb samples when this 

study was conducted. The samples were extracted according to EPA Method 9200.1-86 May 

2008 “Standard Operating Procedure for an In Vitro Bioaccessibility Assay for Lead in Soil.” This 

SOP defines the proper analytical procedure for the validated in vitro bioaccessibility assay for 

Pb in soil (soil which has been homogenized and processed for optimal reproducibility) to 

describe the typical working range and limits of the assay and to indicate potential interferences. 

Users of this SOP are cautioned that deviations in the assay method may impact the results 

(and the validity of the method). Two 10-mL aliquots were removed from the 100-mL extract for 

analysis and storage. Samples were analyzed by ICP/MS following procedures outlined in EPA 

SW-846 Method 6020A.

Calculations. The amount of Pb in the in vitro bioaccessibility extraction is calculated by 

multiplying the extract concentration by the total volume of the bioaccessible extract, which was 

100 mL. The in vitro percent bioaccessibility values were determined by dividing the amount of 

Pb extracted in the in vitro extraction by the total extractable amount of Pb in the sample and 

multiplying by 100. 

17
4.11 Meteorological and Activity Information 

Meteorological information, including air and surface temperatures, wind speed, and 

wind direction information was collected periodically during each monitoring period when 

integrated air sampling was conducted. Air and surface temperatures were always measured at 

the time of air VOC sample collection. Meteorological measurements were made using a 

handheld Kestral 3000 device. This portable device was used so that multiple measurements 

could be made at various sampling locations on and around a site. Surface temperatures were 

made by laying the device on the field or playground surface and waiting for the temperature 

reading to stabilize. Activities occurring at the synthetic turf field and playground locations, if 

any, were noted periodically during each monitoring daytime period. 

18
5. Quality Control and Quality Assurance 

Appendix B includes the data resulting from the QC/QA procedures implemented in this 

study and as outlined in the approved QA project plan developed for this study (U.S. EPA 

2008). The following narrative summarizes these results. 

5.1 Air VOC Quality Control 

Air VOC QC results are shown in Tables B-1, B-2, and B-3. Potential background 

contamination in the sampling and analysis procedure was assessed using field and laboratory 

blanks (Table B-1). Field blanks were 6-L canisters filled with clean air at the laboratory and 

transported and stored with the samples collected at three sampling locations. Potential 

background in the laboratory was assessed using laboratory blanks that were clean air 

delivered to the analytical system. A laboratory blank was analyzed with each of the five sets of 

samples. Except for methyl ethyl ketone (MEK), no analytes were detected in any laboratory 

blank. MEK was measured at levels below the method detection limit in two of the five 

laboratory blanks. MEK was the only analyte detected in two of the three field blanks, at levels 

that were about 5 to 10 times lower than the concentrations measured in air samples. The third 

field blank contained numerous target analytes, often at concentrations exceeding those 

measured in the samples. For example, the concentration of benzene was 1.1 ppbV, and the 

concentration of toluene was 29 ppbV. It is possible that this canister had a leak and was 

contaminated during the storage and transport process. The pressure of each evacuated 

canister used for sample collection was measured prior to collecting the sample to ensure that 

the canister did not leak. Two canisters intended for sampling were found to be at ambient 

pressure prior to use and were not used for sample collection. It is possible that this field blank 

canister also had a leak, but, because it was filled to ambient pressure at the laboratory, it was 

not possible to directly assess this prior to field deployment. 

Recovery of target analytes (Table B-2) was assessed through the analysis of field and 

laboratory controls. Field controls were 6-L canisters filled with air fortified with a subset of 30 

target analytes. These field controls were transported and stored with the samples collected at 

three sampling locations. The same mixture of analytes also was analyzed as three laboratory 

controls to assess recoveries at the analytical step. Except for 1,1,1-trichloroethane and 

1,2,4-trichlorobenzene, the mean recoveries of target analytes in field and laboratory controls 

were within the range of 84% to 114%. The mean recoveries for 1,1,1-trichloroethane and 

1,2,4-trichlorobenzene in field controls were 125% and 62%, respectively. 

Sampling and analysis precision was assessed using duplicate sample collection and 

repeat analysis of samples in the laboratory (Table B-3). Duplicate samples were collected at 

the same site and within a minute of the collection time of the primary sample at three sampling 

locations to assess the precision of the sampling and analysis procedures. Air collected in 

sample canisters at three sampling locations was analyzed a second time to assess laboratory 

analysis precision. Laboratory precision was assessed for 11 analytes with sufficient 

measureable results. Mean relative percent differences (RPDs) ranged from 2.9% to 15.6% for 

repeat analyses. Field sampling and analysis precision was assessed for 12 analytes with 

measurable results. For eight of those analytes, mean RPD values ranged from 1.8 to 21.1%. 

The mean RPD values were higher for four analytes, including hexane (59.7%), meta- and 

para-(m&p)-xylenes (38.4%), toluene (85.8%), and methylene chloride (32.4%). Two of the 

duplicate samples had concentrations of hexane, toluene, and m&p-xylenes that were much 

lower than their corresponding samples. As discussed below, these two field samples also had 

higher concentrations of these three analytes than the other samples collected at different sites 

at the same sampling locations. It is possible that these two field samples were contaminated, 

resulting in the poor measurement precision. 

19
5.2 Air PM10 Mass Quality Control

A single certified flow calibration device (Bios) was used to document the set point and 

final flow rate of each sampler deployed in this effort. Flow rates, start and stop times, and 

sample identification notations were logged into predesignated data collection sheets employed 

for the field effort. A two-party check system was used during the field sampling effort to ensure 

that proper recovery of this data was performed, and that sample identification was correct. 

Two-party checks involved the primary researcher making the initial notation with the reviewer 

(second party) checking the notation independently for correctness. In addition to the data 

review conducted in the field, duplicate (collocated) samples were collected during each 

monitoring episode. This involved setting up a second monitoring station beside the original unit 

at one of the designated site sampling locations (A,B,C,D). The duplicate sampler was run 

under the same conditions as the primary unit, and its data were used to determine the 

precision of the employed methodology. Likewise, field and laboratory blank samples were 

utilized. Laboratory blanks (filter samples from the same single lot of filters used in the study) 

were maintained in the gravimetric laboratory to determine the amount of filter mass changes 

under control conditions. Similarly, field blank samples were deployed in the field at all sites. 

These samples were transported to the field, placed in the sampling apparatus but did not have 

any volume of air pulled through them. Filters treated in such a manner would represent the 

“artifact” mass associated with the sampling effort itself. Following the review of the data 

validation component of this study, it was determined that both the laboratory blanks and the 

field blanks had consistently insignificant quantities of mass loadings (≤2 μg/m3

), and, therefore, 

no blank correction was performed on the sample data. Results from comparisons of the field 

duplicate samples indicate that precision errors ≤10% or mass concentration differences of ~1 

to 2 μg/m3

 were observed between replicates across all sites. All of these are highly acceptable 

values relative to normal data quality indicators for field monitoring efforts. 

5.3 Air PM10 Metals Quality Control

The NERL XRF laboratory employs a sophisticated QA/QC review of instrumentation 

during all analyses. For example, the unit associated with this analysis underwent audit trials 

during the sample analysis runs. Such audits, using National Bureau of Standards or other 

reference materials, provide the means to determine the accuracy of the current instrument 

calibration, as well as other parameters. The instrument has to have both precision (±5%) and 

accuracy (±10%) values from such trials to be considered operational. All such parameters were 

achieved for the reported analysis results. 

5.4 Air PM10 SEM Quality Control

As previously described for the PM10 gravimetric sample collections, field checks were 

conducted pre- and postsampling relative to flow rates. Duplicate samples were collected at 

every regional site to assess precision. The two-party review system again was used to ensure 

proper documentation of field data collections. Laboratory and field blanks were obtained and 

used to assess data quality (reported in Appendix D. These samples indicate that no sample 

handling or storage issues impacted SEM data quality. 

5.5 Wipe, Tire Crumb, and Turf Blade Sample Quality Control and Quality 

Assurance 

5.5.1 Instrument Performance 

Data summarizing the ICP/MS operating parameters, calibration, and method detection 

limits are provided in Tables B-4 through B-7. Table B-8 provides the ICP/MS criteria for 

acceptable data. All ICP/MS instrument QCs met the criteria shown in Table B-8 with the 

20
exception of one serial dilution result for Zn (15%) and one serial dilution result for Al (26%) that 

exceeded the 10% target value. Additional data regarding the results of instrument duplicate 

aliquot analysis, postdigestion spike recoveries, and agreement between serial dilutions are 

provided in the sections below. 

5.5.2 Recoveries 

Extraction performance indicators consisted of recoveries from solution spikes and 

spikes of sample media (Tables B-9, B-10, and B-11 and National Institute of Standards and 

Technology (NIST) Standard Reference Material (SRM) 2710 spikes (Tables B-12 and B-13). 

For the eight spikes prepared in the extraction reagent blank (Table B-10), recoveries for Cr, Pb, 

and Zn were all above 92%. Results for analyte recovery from solutions spiked onto the media 

of interest varied by media (Table B-11). The Ghost wipes were a uniform media. Recoveries for 

the three Ghost wipe spiked samples for Cr, Pb, and Zn were greater than 93%. For the tire 

crumb rubber infill and tire crumb material from playgrounds, there was considerable 

heterogeneity of the material. There was a visual difference between the sample aliquot used 

for spiking and the aliquot designated as “sample,” which was used to correct for the sample’s 

contribution to the total spiked sample concentration. Recoveries for the four spiked tire crumb 

rubber infill samples for the three metals of interest varied from 16% to 553%. For the tire crumb 

samples from playground samples, recoveries range from 17% to 255%. It is probable that 

these recovery ranges reflect the variability in existing metal content across samples and the 

inability to correctly subtract the existing content uniformly without additional sample 

homogenization. 

Extraction reagent blanks and Ghost wipe samples were spiked with NIST SRM 2710, 

where the values for Pb and Zn are certified, and the Cr concentration is provided as 

“information only” in Tables B-12 and B-13, respectively. For the six extraction reagent blanks 

spiked with NIST SRM 2710 (Table B-12), the average recoveries for Pb, Zn, and Cr were 87%, 

76%, and 37%, respectively. For the three Ghost wipe samples spiked with NIST SRM 2710 

(Table B-13), average recoveries for Pb, Zn, and Cr, were 87%, 79%, and 32%, respectively. 

According to the NIST SRM 2710 certificate addendum and EPA 3050B,the median recoveries 

for Pb, Zn, and Cr in 2710 using EPA 3050B are 92%, 85%, and 49%, respectively. Note that 

EPA 3050B is a not total digestion technique but designed to dissolve almost all metals that 

could become “environmentally available.” By design, metals bound in silicate structures 

normally are not dissolved by the EPA 3050B procedure, as they are not usually mobile in the 

environment. 

5.5.3 Analysis of Blank Materials

Nine extraction reagent blanks (identified as “bottle blanks”), one with each batch of 

samples, were processed with the samples (Table B-14). The sample data are reagent blank 

corrected using the bottle blank for the specific batch. Contamination in bottle blanks used for 

correction may cause overcorrection for some samples on some metals. However, the field 

samples also may be subject to this apparently random contamination. Table B-14 shows some 

situations where some metals, such as Cr, Fe, Mn, and Ni, are quite high in the 3050B bottle 

blank data compared to other bottle blank concentrations. The in vitro bottle blanks overall had 

very low concentrations but also showed a few high values. 

Five 3050B-only reagent blanks were prepared with processing beginning at the hotplate 

step. Data from these samples were not used for sample correction. Results were similar to the 

3050B bottle blanks. However, one sample did show very elevated concentrations of Cd, Cr, Fe, 

Mn, and Ni. 

Three laboratory and three field blank ghost wipes were analyzed as samples 

(Table B-15). The two sets of wipes show similar concentrations. The 3050B extracts also 

21
showed a few very high concentrations. The data from these blanks were not used to correct 

the ghost wipe sample data. 

5.5.4 Measures of Precision 

Analytical precision was assessed through the repeat analysis of sample extracts. The 

RPD for repeat analyses was less than the <20% target for the eleven metals (Table B-9). 

Sampling precision also often is assessed by the collection of duplicate (collocated) 

samples. For the surface wipe and tire crumb material collected in this scoping study, this type 

of precision assessment also may assess the homogeneity of the sample media. Results for 

analysis of duplicate aliquots of tire infill material from a sample container or from different 

pieces of tire crumb collected from a playground are reported in Table B-16. For some media, 

there was a large RPD. Given the good analytical precision, the large RPD for duplicate sample 

aliquots or pieces strongly suggests that the materials, as collected and analyzed in this study, 

were not homogeneous with regard to the total extractable amount of some metals. 

5.6 In Vitro Bioaccessibility Analysis Quality Control and Quality Assurance 

A series of procedures and limits were followed to ensure the quality of the in vitro 

extractions and analyses. These QA/QC protocols are reviewed below, and any occurrence of 

nonconformance is noted and addressed. QA/QC for the extraction procedure consisted of a 

series of QC samples (controls, control limits, and corrective actions), as listed in Table B-17. 

All bioaccessibility QC results are summarized in Tables B-18 through B-24) and meet 

the criteria shown in Table B-18, with the exception of the RPD values for the tire crumb 

duplicates (Tables B-23 and B-24) that is believed to result from sample heterogeneity issues. 

This extraction method was designed specifically for soils that have been processed in a 

manner used to create homogeneous samples. The RPD between duplicate extractions of 

these samples ranged from 2.7% to 124% for the infill samples and 4% to 183% for the crumb 

samples. Duplicate extractions of the wipes and blades were not possible either because there 

was a unique sample (wipes) or insufficient sample quantity (blades). 

For the eight Pb spikes prepared in the in vitro extraction solutions (Table B-19), 

recoveries for Pb were all above 90%. The six NIST SRM 2710 extractions (Table B-20) 

resulted in an average RPD of 4.5% (range 0.4% to 8.9%). The RPDs for the three Ghost wipes 

spiked with NIST SRM 2710 (Table B-21) resulted in an average of 4.7% (range 3.5% to 6.2%). 

The NIST SRM RPD values are based on the mean in vitro bioaccessibility values of 75% for 

this SRM (EPA Method 9200.1-86). 

Recoveries for blank Ghost wipes and tire crumb samples spiked with Pb solutions are 

listed in Table B-22. The media were extracted without spikes and used to correct for the 

sample’s contribution to the total spiked samples. Recoveries for the four spiked infill samples 

for Pb ranged from 89% to 104%. Recoveries for the spiked crumb samples, ranged from 87% 

to 103% for Pb, whereas the recoveries for the spiked wipe samples ranged from 87% to 99%. 

Analysis of duplicate tire crumb infill and playground tire crumb aliquots (Tables B-23 and B-24, 

respectively) likely reflects the significant difference in heterogeneity of these samples. 

5.7 Data Quality Assurance Review 

Data generated in NERL/ORD laboratories in this scoping study were reviewed 

independently by a trained QA officer. The review included data generation, calculations, and 

transcriptions for a subset of the data. The Region 1 laboratory followed established laboratory 

QA/QC procedures in their analysis and review of air VOC results. 

22
6. Results 

6.1 Sampling Sites

The full study protocol (collection of all planned air, wipe, and material samples) was 

completed at two synthetic turf field sites (including repeated sampling on a second consecutive 

day at one site, F1). A reduced set of samples that did not include the integrated air particle 

sampling systems was completed at a third synthetic turf field site (F2). In addition, there were 

multiple synthetic turf fields at two sites (F2 and F3 at one site and F4, F5, and F6 at the other), 

and selected wipe and material samples were collected across different fields at these sites. 

The full study protocol, including collection of air samples, was completed at one playground 

(P1). However, because of the size of this playground, only two “on playground” sampling 

locations were operated instead of the three planned. Tire crumb material was obtained from a 

second playground, but no other sampling or site characterization was performed at this 

playground site. Information about each sampling site is provided in Table 2. The samples 

collected at each site are shown in Table 3. 

Table 2. Sampling Site Information and Assigned Codes

Site Type Assigned Code 

EPA Region 5, Field 1, Day 1a Synthetic turf field F1D1 

EPA Region 5, Field 1, Day 2 Synthetic turf field F1D2 

EPA Region 4, Field 2b Synthetic turf field F2 

EPA Region 4, Field 3 Synthetic turf field F3 

EPA Region 4, Field 4c Synthetic turf field F4 

EPA Region 4, Field 5 Synthetic turf field F5 

EPA Region 4, Field 6 Synthetic turf field F6 

EPA Region 3 Playground P1 

EPA Region 4 Playground P2 a

Samples were collected at one synthetic turf field on 2 consecutive days. b

Two synthetic turf fields (F2 and F3) were part of the complex at this site. c

Three synthetic turf fields (F4, F5, and F6) were part of the complex at this site. 

Table 3. Overview of the Types of Samples Collected at Each Site 

Site 

Air 

VOC 

Air 

PM10

Mass 

Air 

PM10

Metals 

Air 

PM10

SEM 

Surface 

Wipes 

Tire 

Infill 

Turf 

Blades 

Tire 

Crumb 

F1, Day 1 ● ● ● ● ● ● ●

F1, Day 2 ● ● ● ● ●

F2 ● ● ● ●

F3 ●

F4 ● ● ● ● ● ● ●

F5 ● ● ●

F6 ● ● ●

P1 ● ● ● ● ●

P2 ●

23
Fewer synthetic turf fields and playgrounds were monitored than originally planned, and 

at sites near only three of the four NERL facilities. This was primarily because of difficulties in 

identifying and arranging access to sites in combination with the logistical difficulties posed by 

the extensive array of equipment and skill required to operate the active particle sampling 

equipment at multiple sampling locations per site. Sampling at fewer sites had minimal impact 

on accomplishing the study goals, as the original design was very limited. Implementing the full 

protocol at only two synthetic turf field sites resulted in little impact in the methods evaluation 

study. Samples were collected at these two sites during relatively hot, dry days and with high 

activity levels (conditions favorable for the evaluation). The consecutive day measures at one 

site yielded additional data for assessing the methodology and understanding potential changes 

in site conditions from day to day. Sampling at only one playground site, although one with 

relatively high levels of activity, did provide insights regarding the practical issues regarding 

implementing the protocol at playground sites but resulted in limited data for the workgroup. 

6.2 Site Characteristics 

Descriptive information about each sampling site, including the age and type of material, 

maximum temperatures, wind speed, and activity information is provided in Table 4. Some 

anecdotal information may be relevant with regard to interpreting the study results. Sampling 

was conducted at field F1 on 2 consecutive days (F1D1 for day 1 and F1D2 for day 2). New tire 

crumb infill material recently had been applied to field F1. During the first day at field F1 (F1D1), 

heat thermals were observed coming off of the field during the hottest times of day, and there 

was a smell that generally is associated with tires or tire crumbs. There was considerable 

activity on this field throughout the day, including multiple physical education classes, as well as 

football and soccer practices. On the second day at field F1 (F1D2), the temperature was 

somewhat cooler, no thermals were observed, a similar smell was noted, and there were lower 

activity levels. Air PM sampling equipment was either on or immediately adjacent to field F1 

during the activities. Fields F2 and F3 were adjacent fields at the same regional site. There was 

no activity at these fields during the monitoring period; therefore, no air PM samples were 

collected. Fields F4, F5, and F6 were collocated at another regional site. Air PM samples were 

collected on the sidelines of field F4. There was sporadic moderate activity on field F4 and on 

the immediately adjacent field (F5) during the monitoring day, including physical education 

classes, flag football, and a soccer game. One air PM sampling location was placed between 

fields F4 and F5. Two air PM sampling locations were placed on the opposite field F4 sideline 

based on wind direction at the beginning of the monitoring. The wind shifted later in the day and 

may have transported VOCs and particles to these two sampling locations (particularly to 

sampling location A) from the adjacent parking deck and nearby road with moderate commuter 

traffic. At playground P1, the playground was used by up to 60 preschool and early elementary 

students twice during the school day, and sampling continued for approximately 90 min into 

after-school use by approximately 12 to 20 students. The tire crumb material at playground P1, 

with embedded and visual fibers, was prepared and provided by a local supplier. 

The air monitoring equipment setup at one sampling location at site F1 is shown in 

Figure 1, wipe sampling is shown in Figure 2, the turf blade and tire crumb infill at the surface is 

shown in Figure 3, and the multiple colors of turf blade are shown in Figure 4. A laboratory 

close-up of a sample vial containing tire crumb infill granules collected at site F2 is shown in 

Figure 5. Tire crumb material at site P1 is shown in Figure 6, and a laboratory close-up of this 

tire crumb material, with exposed fibers, is shown in Figure 7. A laboratory close-up of the 

“wood bark” tire crumb material collected at site P2 is shown in Figure 8. 

24
Table 4. Site Information

Site 

Surface 

Age Type of Surface Material 

Temperature at 

Time of Air VOC 

Sample Collectiona

General Activity 

Levels on 

Monitoring Day 

F1 

Day 1 

(F1D1) 

2 yearsb Polyethylene turf bladesc

; green 

field, red end zones, black and 

white lines; with granular tire 

crumb rubber infill 

32 °C Air above field 

50 °C Field surface 

Wind 2-11 mph 

Est. number: 20-70 at 

a time 

Est. duration: 

45-120 min at a time 

F1 

Day 2 

(F1D2) 

2 yearsb Polyethylene turf bladesc

; green 

field, red end zones, black and 

white lines; with granular tire 

crumb rubber infill 

35 °C Air above field 

46 °C Field surface 

Wind 1-6 mph 

Est. number: 20-70 at 

a time 

Est. duration: 

30-45 min at a time 

F2 4 years Polyethylene turf bladesc; green 

field, red center circle, white 

lines; with tire crumb rubber 

infill 

28 °C Air above field 

44 °C Field surface 

Wind 1-11 mph 

Number: 0 

Duration: 0 

F3 5 years Polyethylene turf bladesc; green 

field, red center circle, white 

lines; with tire crumb rubber 

infill 

―d ―

F4 4 years Polyethylene turf bladesc; green 

field; yellow and white lines; 

with tire crumb rubber infill 

30 °C Air above field 

44 °C Field surface 

Wind calm (2 mph) 

Est. number: 10-35 at 

a time 

Est. duration: 

45-120 min at a time 

F5 3 years Polyethylene turf bladesc; green 

field, yellow and white lines; 

patched area appeared to be 

green nylon turf bladesc

; with 

tire crumb rubber infill 

― ―

F6 2 years Polyethylene turf bladesc; green 

field, yellow and white lines; 

with tire crumb rubber infill 

― ―

P1 4 years Shredded tire material; black 

color; much of the tire crumb 

had fiber material still included. 

30 °C Air above 

playground 

36 °C Playground 

surface 

Wind calm (1 mph) 

Est. number: 12-60 at 

a time 

Est. duration: 

30-90 min at a time 

P2 Not 

known 

Tire crumb material processed 

and formed to simulated bark 

appearance; multiple green and 

brown colors. 

― ―

a

VOC air samples collected at hottest time of day (~2 p.m.). b

Additional new tire infill applied during summer prior to sampling. 

c

Type of turf blade material based on visual assessment (not confirmed through material analysis). d

Not measured or not monitored. 

6.3 Sample Collection 

The numbers and types of samples collected at each site are shown in Table 5. Air samples for 

VOCs were collected in evacuated 6-L Summa-polished stainless steel canisters at a 1-m 

sampling height. Four air VOC samples were collected at each of three synthetic turf field sites 

25
Figures 1 through 4. Site F1 particle air samplers (top), surface wipe sample collection (left), green 

turf blade with black granular tire crumb (middle right), and multiple turf blade colors (lower right). 

(F1, F3, and F4) with tire rubber infill material. Three air samples were collected at one 

playground site (P1) with tire crumb rubber material. Samples were collected at three different 

sampling locations (designated as A, B, and C, respectively) directly above each of the synthetic 

turf fields and at two different sites (A and B) directly above the playground. A background 

sample (designated as D) also was collected at each site a short distance upwind from the field

26
Figures 5 through 8. Tire crumb infill granules from site F2 (top left), shredded tire crumb at site 

P1 (top and bottom right), and tire crumb material from site P2 (bottom left). 

or playground. With one exception, all air samples were collected at each site on 1 day and at 

approximately the same time of day. The exception was the collection of a set of four air 

samples on 2 consecutive days at one synthetic turf field. All grab air VOC samples were 

collected during the hottest time of day (~2 p.m.). In general, these grab air VOC samples were 

simple to collect, required little onsite collection time, and modest technical expertise. We found 

it was very important to verify the canister pressure prior to sampling to ensure that the 

evacuated canisters had not leaked prior to sample collection. 

Integrated air PM10 samples for mass and metals concentration measurement, as well 

as separate integrated air samples for SEM analysis, were collected at a 1-m sampling height at 

the four VOC sampling locations at synthetic turf field F1 on 2 consecutive days, and on 1 day 

at field F4. Air PM10 samples were collected at the three VOC sampling locations on 1 day at 

playground P1. The limited sampling performed at playground P1 was based on the small space 

that did not allow the full complement of the normal sampling routine to be performed. In all 

events, active sampling locations were established quickly on the site, as well as from a 

background sampling location. Air monitoring was initiated for all monitors in quick order on their 

setup and calibration and continued without interruption through the monitoring event (daytime). 

This resulted in sample collections ranging from approximately 5.8 to 7.8 h and corresponding 

individual air volumes ranging from approximately 7.0 to 9.2 m3

 over the course of a sampling 

day. Collection of up to 10 air particle samples at each site required considerable equipment 

(enough to fill a van), considerable setup and retrieval time (approximately 1 h each), extensive

staff time onsite (typically 8 to 10 h for two people), and moderate technical monitoring 

expertise. The monitoring approach, equipment, and sampling durations were selected to obtain

27
Table 5. Number of Samples Collected at Each Site 

a

F = synthetic turf field, D = day 1 or day 2, P = playground. 

Sitea 

Onsite 

Samples 

Background 

Samples 

Duplicate 

Samples 

Archival 

Samples 

Field 

Blanks 

Field 

Controls 

Air VOC 

 F1D1 3 1 1 ― 1 1 

 F1D2 3 1 ― ― ― ―

 F2 3 1 ― ― ― ―

 F4 3 1 1 ― 1 1 

 P1 2 1 1 ― 1 1 

Air PM10 for Mass and Metals 

 F1D1 3 1 1 ― 1 ―

 F1D2 3 1 1 ― 1 ―

 F4 3 1 1 ― 1 ―

 P1 2 1 1 ― 1 ―

Air PM10 for SEM 

 F1D1 3 1 1 ― 1 ―

 F1D2 3 1 1 ― 1 ―

 F4 3 1 1 ― 1 ―

 P1 2 1 1 ― 1 ―

Surface Wipes 

 F1D1 3 ― 3 3 1 ―

 F1D2 3 ― 3 3 ― ―

 F2 3 ― 3 ― 1 ―

 F4 1 ― 1 1 1 ―

 F5 1 ― ― 1 ― ―

 F6 1 ― ― 1 ― ―

Tire Infill 

 F1D1 3 ― ― ― ― ―

 F2 3 ― 3 ― ― ―

 F4 1 ― 1 ― ― ―

 F5 1 ― ― ― ― ―

 F6 1 ― ― ― ― ―

Turf Blades 

 F1D1 3 ― ―- ― ― ―

 F1D2 1 ― ― ― ― ―

 F2 3 ― ― ― ― ―

 F3 4 ― ― ― ― ―

 F4 1 ― ― ― ― ―

 F5 1 ― ― ― ― ―

 F6 1 ― ― ― ― ―

Tire Crumb 

 P1 2 ― 1 2 ― ―

 P2 1 ― ― ― ― ―

adequate limits of detection for PM10 mass and a range of metal analytes to ensure that levels 

typically found in ambient air would be measurable. 

Surface wipe samples were collected at three “on field” sampling locations at synthetic 

turf fields F1 (on 2 consecutive days) and F2. At a third site, a single surface wipe sample was 

28
collected from each of three fields (F4, F5, and F6), as the three fields making up this complex 

were of different ages. A standard wet-wipe method (ASTM E1728-03) that is used to measure 

residential surface dust Pb levels was employed for sample collection in this study. In the 

absence of a validated wipe method for synthetic turf surfaces, this method was selected for 

evaluation in this study. In general, the advantages of this method were the availability of 

standard wipe material and existing analytical methodology. In practice, samples could be 

collected by those with moderate technical expertise at multiple sampling locations in a 

relatively short period of time. However, the sampling procedure was not as simple as for 

smooth floor materials, with the synthetic turf blades requiring additional patience and control. 

The relationship between the dust collected on the wipe sample that comes from turf blades 

versus the dust from the infill and is available for human contact is not clear and may need 

further investigation. Most wipes also picked up a few pieces of the rubber infill material and turf 

blades. A decision was made to remove these relatively large discrete materials in the 

laboratory prior to extraction as these larger materials would be characterized as part of the 

additional material samples. It is not expected that removal of these large materials would 

impact the measurement of the small dust particles that the surface wipe sample is designed to 

collect. 

Tire crumb rubber infill used in these synthetic turf field installations was collected from 

three sampling locations at fields F1 and F2 and at single sampling locations from each of three 

fields (F4, F5, and F6) at the third site. Sample collection could be completed in a short time by 

persons with minimal technical expertise. In this study, it was decided to collect infill material 

that was already available at the surface rather than by dislodging material trapped deep within 

the turf blades. This decision was based partly on avoiding potential damage to field 

components but primarily because the material on the surface was more available for potential 

human contact. However, infill material was not available uniformly across the field surface. 

Synthetic turf blade samples were collected at all field sites in this study. The synthetic 

turf blades were not a primary interest in this study, as the characterization of this type of 

material is being performed by other organizations. However, samples of turf blades were 

collected to enable an improved understanding of the surface wipe measurements with regard 

to the potential differential contributions from the infill and blades. A decision was made not to 

perform destructive collection (i.e., there was no cutting of material from the fields). Instead, the 

collection relied on the availability of loose blades found at the surface of the fields. Collection 

and analysis decisions were complicated by the limited availability of loose blades and a later 

decision that a minimum of 0.7 g of material was required for analysis. Collection of blades of 

each color type was attempted. For fields F1, F2, and F3, the colors were collected separately 

and kept separate for analysis. None of the green blade samples from the site complex 

comprised of fields F2 and F3 achieved the “postsampling” requisite 0.7-g sample size, and 

they, therefore, were not analyzed. In retrospect, a decision to combine green blades from 

several different sampling locations would have enabled the analysis of a composite site 

sample. For fields F4, F5, and F6 the different colors for each field were mixed together in the 

sample to best achieve adequate sample sizes, while, at the same time, obtaining samples from 

fields of different ages. 

Tire crumb rubber samples were obtained from two playground sites. The material used 

at the P1 playground consisted of shredded tire particles containing fibers, whereas the material 

from playground P2 was processed and colored to simulate tree bark. Collection of tire crumb 

material is a simple process. However, the material is relatively heterogeneous and it is not 

clear how many pieces or which pieces need to be collected for site characterization. It is also 

not clear whether it is most appropriate to collect tire crumb pieces at the surface that may have 

experienced different weathering and contact than underlying pieces. A further challenge is that 

relatively small amounts (1 g or less) are required for analysis because larger amounts may 

overwhelm digestion and analytical systems. Intact tire crumb rubber pieces are generally larger 

29
30

than 1 g. A decision was made not to cut the tire crumb pieces because exposing unweathered 

surfaces might impact the Pb bioaccessibility measurement. 

6.4 Summary Measurement Results 

Tables 6 through 8 provide key data summaries for the synthetic turf field and 

playground sites. All of the individual site sample data are provided in Appendix C. 

6.5 Air VOC Measurement Results (Appendix C, Table C-1) 

Key highlights from the grab air VOC measurements are summarized below. 

• Twelve of the 56 target VOC analytes were present in multiple samples. Thirty-seven of the 

56 analytes were not detected in any sample. Seven of the remaining 19 analytes had 

detectable levels in only one or two samples. 

• Measured VOC concentrations were generally low. No analyte concentration exceeded 

1 ppbV in any sample. Detection limits ranged from 0.070 to 0.079 ppbV for most analytes, 

and 0.14 to 0.16 ppbV for 1,3-butadiene and m&p-xylenes. 

• MIBK previously has been identified as a tire-related VOC. MIBK was present in three “on 

field” samples collected at one synthetic turf field (F1) on the first monitoring day when heat 

thermals were observed and in two “on field” samples on the second consecutive day of 

monitoring. MIBK concentrations were low (<0.2 ppbV) in all five samples. MIBK was not 

detected in the background samples collected near the field on either day. MIBK was not 

detected at any other site in this study. 

• Concentrations of the other VOCs routinely measured over the field or playground sampling 

locations were similar to the concentrations measured in corresponding upwind background 

samples collected nearby, or they likely could be explained by documented local sources near 

the site.

• MEK was measured in all the study samples, with the “on field” MEK levels being similar to 

levels in the upwind background samples at each site. 

• Hexane was present in most of the “on field” and background samples. At the F4 synthetic 

turf field, the hexane concentrations at all three “on field” sites were higher than the 

background site, but all concentrations were low (<0.2 ppbV). 

• The aromatic analytes benzene, toluene, and m&p-xylenes are ubiquitous atmospheric 

pollutants and were present at measureable levels in most samples collected in this study. 

• Benzene concentrations were similar for the background and “on field” samples at all sites. 

The highest benzene concentration (0.32 ppbV) was measured at location A on site F4. This 

concentration was higher than at sites B or C or the background site D. Other aromatic VOC 

concentrations also were elevated somewhat at this sampling location and site. Sampling 

location A was closest to a parking garage exit and may have been impacted by traffic and 

vehicle exhaust. 

• Toluene, m&p-xylenes, and hexane concentrations at site P1 location B, and at site F1 

location B, were higher than concentrations at the other sampling locations for these sites. 

The reason for this is not clear; however, elevated levels (>4 ppbV) of these compounds were 

measured in one field blank, and contamination of the sampling canisters cannot be ruled out. 

Both of these samples had a corresponding duplicate sample collected at location B. 

Concentrations of these three analytes were present in the duplicate samples at ratios 

ranging from 0.15 to 0.63 of the concentrations in the samples. In fact, the concentrations 

measured in the duplicate samples were similar to the concentrations measured in the other 

samples at each site, further suggesting that these two samples with slightly higher 

concentrations may have been contaminated. 

• Several halogenated VOCs were measurable in all or most of the samples. These included 

carbon tetrachloride, methylchloride, methylene chloride, dichlorodifluoromethane (Freon 12), 
31

Table 6. Summary Results for Selected Analytes in Air Samples Collected at Synthetic Turf Fields and a 

Synthetic Turf Fields 

F1D1 F1D2 F2 F4 

On Back- On Back- On Back- On 

Air Samples Analyte Unit Fielda grnd.b Fielda grnd.b Fielda grnd.b Fielda Air PM Mass Particle Mass μg/m3 27.8 29.5 29.8 29.5 ― ― 31.8 Air PM Metals Pb ng/m3 NDc ND 7.7d 6.3 ― ― ND 

Cr ng/m3 2.9 2.0 3.6 3.3 ― ― ND 

Zn ng/m3 10.8 23.8 11.8 11.6 ― ― 31.4 

Air VOCs Methyl Isobutyl Ketone ppbV 0.13 ND 0.12 ND ND ND ND 

Benzene ppbV 0.09 0.07 0.08 0.09 0.11 0.12 0.20 

Toluene ppbV 0.42 0.15 0.11 0.12 0.18 0.19 0.28 

m&p-Xylenes ppbV 0.17 0.08 0.10 ND 0.07 0.08 0.14 

Hexane ppbV 0.21 0.06 0.08 0.08 0.08 0.05 0.14 

Methyl Ethyl Ketone ppbV 0.47 0.44 0.38 0.36 0.41 0.37 0.43 

Carbon Tetrachloride ppbV 0.09 0.10 0.10 0.10 0.09 0.08 0.09 

Dichlorodifluoromethane ppbV 0.52 0.55 0.50 0.56 0.56 0.51 0.48 

Methylchloride ppbV 0.47 0.48 0.47 0.46 0.45 0.45 0.48 

Trichloro-fluoromethane ppbV 0.26 0.28 0.26 0.27 0.27 0.25 0.24 Trichloro-trifluoroethane ppbV 0.08 0.08 0.08 0.08 0.08 0.07 0.07 

Methylene Chloride ppbV 0.07 0.06 ND ND 0.06 0.06 0.06 

aAverage of two or three “on field” or “on playground” measurements (any nondetect values were not included in the average). bSingle measurement from upwind background location. cNot detected. dPb was measured in only one of three “on field” samples at F1D2 and one of two “on playground” samples at P1. 
32

Table 7. Summary Results for Total Extractable Pb, Cr, and Zn in Samples Collected at Synthetic Turf FiPlaygrounds 

Synthetic Turf Fields 

F1D1 F1D2 F2, F3 F4, F5, F6 P

Sample Analyte Unit Range Range Range Range RanTurf Field Surface Wipe Samples Pb μg/ft2 0.3-1.9 0.4-1.4 0.3-0.5 0.1-0.2 NC

Cr μg/ft2 0.1-0.5 0.1-0.3 ND.b ND-0.3 N

Zn μg/ft2 21.3-43.3 26.4-40.6 9.2-19.3 4.3-13.6 N

Turf Field Infill Crumb Rubber Pb μg/g 13.1-34.7 NC 20.6-61.2 10.7-47.7 N

Cr μg/g 0.3-1.0 NC 0.4-0.9 0.3-1.0 N

Zn μg/g 5,050-19,200 NC 3,120-12,300 2,660-11,400 N

Turf Field Blades Pb μg/g 2.8-389c NC 2.4-2.8d 2.1-701e N

Cr μg/g 1.0-73.1 NC 1.2-1.9 3.7-177 N

Zn μg/g 316-730 NC 199-255 131-206 N

Playground Tire Crumb Pb μg/g NC NC NC NC 1.0-4

Cr μg/g NC NC NC NC 0.3-

Zn μg/g NC NC NC NC 4,300-1

aNot collected. bNot detected. cDifferences noted for different blade colors (red = 389 μg/g; white, green, and black all <4.3 μg/g). dAnalysis of red and white blades. eHighest level (701 μg/g) found in a field with a repaired area; levels in blades from two adjacent fields ranged from 2.0 to 77 μg/g. fAnalysis of seven pieces of tire crumb; six of those pieces had Pb levels <50 μg/g. 

es of tire crumb. gAnalysis of two piec
33

Table 8. Summary Results for Estimates of Pb Bioaccessibility in Samples Collected at Synthetic Turf FPlaygroundsa

Synthetic Turf Fields 

F1D1 F1D2 F2, F3 F4, F5, F6 P1 

Sample Analyte Range Range Range Range RangTurf Field Infill Crumb Rubber Pb 1.6%-9.6% NC b 1.7%-7.6% 1.7%-10.1% NC Turf Field Blades Pb 2.3%-86.8%c NC 38.7%-40.3%d 0.2%-54.4%e NC Playground Tire Crumb Pb NC NC NC NC 0.3%-10

aThe in vitro bioaccessibility method has not been validated for these materials. bNot collected. cDifferences noted for different blade colors (red = 2.3%, white and green = 40.9% to 43.0%, and black = 86.8%); also, the lowest bioacc

corresponds to the sample with the highest total extractable Pb (389 μg/g). dAnalysis of red and white blades. 

eLowest bioaccessibility value (0.2%) corresponds to the sample with the highest total extractable Pb (701 μg/g). 

 μg/g) fLowest bioaccessibility value (0.3%) corresponds to the sample with the highest total extractable Pb (443
trichlorofluoromethane (Freon 11), and trichlorotrifluoroethane (Freon 113). In all cases, the 

levels in the “on field” samples were similar to levels in the upwind background sample at 

each site. 

6.6 Air PM10 Mass Measurement Results (Appendix C, Table C-2)

PM10 concentrations observed across all of the sites ranged from approximately 24 to 

33 μg/m3

. PM10 mass concentrations collected on or adjacent to synthetic turf fields were 

generally equivalent to concentrations in ambient air measured at the upwind background sites. 

Mass concentrations across a given synthetic turf field or playground were often consistent 

within themselves. That is, PM10 concentrations from field sampling locations A, B, and C at a 

given site often varied by only 2 to 3 μg/m3

, which was within the precision error typically 

observed for the duplicates. This mass consistency was generally true regardless of the range 

of activities taking place on the field and the proximity of such activities to a given monitor. Such 

a statement, however, cannot be made for the one playground site monitored. Comparison of 

data from the P1 site indicates an approximately 15 μg/m3

 higher PM10 mass concentration was 

obtained from the monitor located near the highest density of playground activity (location B). 

6.7 Air PM10 Metal Measurement Results (Appendix C, Table C-3)

Air PM10 sample filters were analyzed for 44 metals. As part of the analysis, the statistical 

uncertainty of the measurement was determined; the measured metal concentrations must be at 

least three times the uncertainty concentration to be considered a measured result. Based on 

this assessment, the full list of 44 metals was reduced to 12 that are reported in Appendix C-3, 

including the primary analytes Pb, Cr, and Zn (see Table 6), as well as 8 other elements (Ca 

[calcium], Cl [chlorine], Cu, Fe, K [potassium], Mn, S, Si [silicon], and Ti [titanium]) with sufficient 

number of measurable results for assessment within and across sampling sites. 

Measurement results from synthetic turf field F1 show that upwind background levels of 

Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, and Pb were similar to the “on field” concentration 

measurements at thee sampling locations (A, B, and C). This would indicate that the infill tire 

crumb rubber and other materials on the turf field examined in F1 (on both day 1 and day 2) 

provided little contribution to the measured metal concentrations associated with airborne 

aerosols. Slightly higher concentrations of Ti (~36%), Cr (~90%), Mn (~100%), Fe (~74%), Cu, 

(~57%), and Zn (~65%) were measured at the “on field” monitors relative to the upwind 

background sampling location at the F4 synthetic turf field. This site was bordered by both a 

busy urban commuter road, as well as a parking deck. Because of this, the additional 

contribution of some of the metals to the collected "on field” air samples, notably those that often 

are observed in near-roadway air samples (Fe, Zn, and Cu) might not be singularly reflective of 

contributions from a single source (i.e., this might be indicative of near-road influence, as well as 

of any contribution from any resuspended tire crumb rubber infill aerosol). 

It would appear that the “on playground” samples associated with the P1 site had 

consistently higher levels of the 12 selected metals discussed above, as compared with the 

background site. For example, “on playground” aerosol metal concentrations for Si, Cl, K, and 

Ca were sometimes 50% to 700% higher, as compared with the background. These metals 

often are associated with crustal (soil) related sources. “On playground” samples had much 

higher levels of metals that might be of relevance to tire crumb rubber components. For 

example, Ti concentrations were more than four times higher for one “on playground” sampling 

location, with nonspeciated Cr concentrations (~3 ng/m3

) substantially higher than the 

background monitor. 

Mn concentrations were ~7 times higher (15 ng/m3

), with Fe as much as 4 times more 

concentrated (~1,000 ng/m3

). Of particular interest are Zn levels, which were 8 to 11 times 

higher than background levels for the two “on playground” monitors (82 to 117 ng/m3

). On the 

34
other hand, these metals also may be found in soils, so the relative contribution of tire crumb 

particles to the increased levels could not be determined readily from these results. 

Pb concentrations were at measurable levels in only 3 of the 18 air PM samples 

collected in this study. These three samples had concentrations (≤7.7 ng/m3

) that were near the 

method detection limit. The maximum concentration of 7.7 ng/m3

 was measured in a sample 

collected at a synthetic turf field and, given the precision of the method, is considered 

indistinguishable from the corresponding background level (6.3 ng/m3

). A Pb level of 5.1 ng/m3

was measured at one “on playground” sampling location; again, a level near the method 

detection limit. The samples for another “on playground” sample, its duplicate sample, and the 

background sampling location had Pb values below the method detection limit. 

6.8 Air PM10 SEM Measurement Results (Appendix C, Table C-4)

Air PM10 samples were collected on filters at three sites with tire crumb material for SEM 

analysis. Air samples collected at two “on field” or “on playground” sampling locations and at 

one upwind background sampling location were analyzed for synthetic turf fields F1 and F4 and 

playground P1. In preparation for analyzing the air samples, samples of the tire infill material 

from a field and the crumb material from a playground were analyzed to determine whether 

metal or morphological “source profiles” could be identified that would assist in identifying tire 

crumb-related particles in the air samples. A detailed report describing the SEM analysis 

procedure and measurement results is provided in Appendix D. Key findings from the SEM 

analysis are described below. 

• Prior to analyzing the air filter samples, particles were generated from the tire crumb materials 

collected at the turf fields and playground to try to identify a signature morphology and metals 

composition for tire crumb particles. These particles did not show a unique, easily identifiable 

X-ray spectrum for metals composition or supporting a definitive source attribution analysis. 

C and S were consistently present in the tire crumb particles. Zn usually but not always was 

observed in tire crumb particles, often at trace levels. Tire crumb particles from the source 

material varied considerably in morphology, making it difficult to identify a typical or 

characteristic tire crumb morphology. 

• Very few fibers were observed in any of these air samples, and none could be attributed to 

tire crumb. This was true even for the playground site (P1) air samples, which had tire crumbs 

with exposed and embedded fibrous material. 

• The ability to quantify the tire crumb concentration in these samples hinges on the tire crumb 

particles having a unique composition or morphology that would enable the analyst to identify 

tire crumb particles with a high degree of confidence. This does not seem to be the case for 

tire crumb particles collected in this study, as seen in the variety of morphologies and 

compositions on air filters. 

• At the two synthetic turf fields, mass concentrations for postulated tire crumb particles were 

estimated to be only a very small fraction of the total PM10 mass concentrations measured at 

these sites. At the playground site, estimated mass concentrations for postulated tire crumb 

particles were a relatively small fraction of the total PM10 mass concentrations, but a higher 

fraction than was measured at the synthetic turf fields. However, the variability in tire crumb 

particle composition and morphologies introduces large uncertainties in these results.

6.9 Total Extractable Metals in Synthetic Turf Field Surface Wipe, Tire Crumb 

Infill, and Turf Blade Samples and Playground Tire Crumb Rubber Samples 

(Appendix C, Tables C-5 through C-8) 

The total extractable measurement results for 11 metals in wipe, tire crumb, and 

synthetic turf blades collected in the scoping study are shown in Appendix C. Primary target 

metals were Pb, Cr, and Zn (see Table C-5), and metals of secondary interest included Al, As, 

35
Ba, Cd, Cu, Fe, Mn, and Ni. Results from surface wipe samples collected at synthetic turf fields 

are shown in Table C-5, those for tire crumb infill from synthetic turf fields are shown in 

Table C-6, and those for synthetic field turf blades are shown in Table C-7. Results for tire 

crumb material at playgrounds are shown in Table C-8. 

6.9.1 Surface Wipes from Synthetic Turf Fields (Table C-5) 

Surface wipe samples were collected at different sampling locations from several 

synthetic turf fields. The sampling locations were in close proximity to the air monitoring “on 

field” locations. In some cases, duplicate samples were collected side-by-side. Some wipe 

samples were collected from different color turf blade areas at one site (F1) where there were 

large areas of different color turf blades. A wipe sample also was collected at the field (F5) with 

visually different turf materials. Total extractable metal measurement result highlights include 

those that follow. 

• Total extractable Pb was less than 2.0 μg/ft2 in all surface wipe samples collected at the 

synthetic turf fields in this study. Most results were less than 1.0 μg/ft2

. 

• Many of the sample analysis results were similar to levels measured in field blanks, which had 

Pb values ranging from 0.14 to 0.54 μg/ft2

. 

• The highest total extractable Pb value (1.9 μg/ft2

) was measured on a surface wipe collected 

at site F1 on red synthetic turf blades. 

• Surface wipe samples collected side-by-side, in some cases, had similar total extractable Pb 

levels; in other cases, the differences in side-by-side measurements ranged up to 

approximately twofold. Some of the side-by-side measures taken at one turf field site (F1) 

were from an area of mixed turf blade colors. 

• Surface wipe samples collected at different locations on synthetic turf fields had up to sixfold 

differences in total extractable Pb concentrations. The greatest differences appeared to be 

associated with wipes taken from areas with different blade colors. 

• Total extractable Cr was <0.6 μg/ft2

 in all surface wipe samples. 

• Total extractable Zn in surface wipe samples ranged from 4.0 to 43 μg/ft2

. 

• Measurements of As were very low (≤0.1 μg/ft2

) and similar to amounts found on field blanks. 

• Most Cd measurements were less than the method detection limit; the remainder were 

≤0.025 μg/ft2

. 

6.9.2 Tire Crumb Infill at Synthetic Turf Fields (Table C-6) 

Samples of tire crumb infill granules were collected at different sampling locations from 

several synthetic turf fields. The sampling locations did not necessarily correspond to the 

sampling locations where the other samples were collected. In some cases, duplicate samples 

were collected side-by-side. In addition, second aliquots of material collected in each sample 

container were analyzed, so that there were two analysis results for each sample or duplicate 

sample. 

It is important to remember that the methods for collection and analysis have not been 

validated. Total extractable metal measurement result highlights include the following. 

• Total extractable Pb concentrations in tire crumb infill from synthetic turf fields ranged from 11 

to 61 μg/g. 

• There was considerable variability (up to an approximately fourfold difference) in total 

extractable Pb concentrations for different aliquots randomly taken from the same sample 

container. 

• The variability among locations at a site and among different sites was similar to the variability 

in Pb measurement results for aliquots taken from the same container (up to approximately 

fourfold). 

• Total extractable Cr concentrations ranged from not detected to 1.0 μg/g. 

36
• Total extractable Zn concentrations ranged from 2,600 to 19,000 μg/g. 

• The variability in Zn concentrations for aliquots taken from the same container was less than 

the variability observed in Pb concentrations. 

• Concentrations of As ranged from not detected to 0.55 μg/g. 

• Cd concentrations ranged from not detected to approximately 1.5 μg/g. 

6.9.3 Turf Blades at Synthetic Turf Fields (Table C-7) 

Characterization of the turf blade material was not a primary goal of this scoping study; the 

focus of this study was on the tire crumb components. However, these samples were collected 

and analyzed to help improve interpretation of the surface wipe measurements. It is important to 

remember that the methods for collection and analysis have not been validated for this material. 

Samples of synthetic turf blades were collected at different sampling locations from several 

synthetic turf fields. Where possible, samples of different colors were collected but, because of 

the small sample sizes, could not always be analyzed separately. The sampling locations did 

not necessarily correspond to the locations where the other samples were collected. Total 

extractable metal measurement result highlights are as follows. 

• Total extractable Pb concentrations from synthetic turf blades ranged from 2.4 to 700 μg/g. 

• The highest total extractable Pb concentration (700 μg/g) was measured from blades in a 

sample collected at a turf field (F5), which included an area that had apparently been repaired 

with a section of turf material visually different from the rest of the field. Mixed-color turf blade 

samples taken from two adjacent fields (F4 and F6) at the same site had Pb levels ranging 

from 2.0 to 77 μg/g. 

• The second highest total extractable Pb concentration (389 μg/g) was measured in red blades 

at another turf field site (F1). Pb concentrations for green, white, and black blades collected 

from this same site ranged from 2.8 to 4.3 μg/g. 

• Total extractable Cr concentrations ranged from 0.1 to 180 μg/g. The level of Cr generally 

appeared to be lower than but correlated with the corresponding Pb concentrations.

• Total extractable Zn concentrations ranged from 130 to 730 μg/g. Zn levels in white and black 

blades collected at one site (F1) were about twofold higher than in green and red blades at 

the same site and about three to five times higher than levels measured in blades from the 

other two synthetic turf field sites.

• Concentrations of As and Cd were less than 0.6 μg/g in all samples. 

6.9.4 Tire Crumb Material from Playgrounds (Table C-8) 

Samples of tire crumb pieces were collected at different sampling locations at two 

playgrounds. Seven pieces of crumb rubber from one playground (P1; shredded tires with 

exposed fibers) and two pieces from the second playground (P2; with simulated bark tire crumb 

material) were analyzed. It is important to remember that the methods for collection and 

analysis have not been assessed or validated. Total extractable metal measurement result 

highlights include those described below. 

• Total extractable Pb concentrations in five pieces of shredded tire crumb from P1, the 

playground with fibrous materials, ranged from 1.0 to 6.3 μg/g. A Pb concentration of 46 μg/g 

was measured in a sixth piece, and 440 μg/g Pb was measured in a seventh piece, 

documenting the heterogeneity of Pb in these site samples. 

• Total extractable Pb concentrations from two simulated bark tire crumb samples collected at a 

second playground (P2) were 3.4 and 7.8 μg/g. 

• Total extractable Cr concentrations ranged from 0.3 to 3.0 μg/g. 

• Total extractable Zn concentrations ranged from 4,300 to 18,000 μg/g. 

• The variability in Zn concentrations was less than the variability observed in Pb 

concentrations. 

37
• Concentrations of As ranged from 0.04 to 0.96 μg/g, except for a value of 15 μg/g that was 

measured in the same P1 crumb piece with the highest Pb level (440 μg/g Pb). 

• Cd concentrations ranged from 0.09 to 10.5 μg/g, with the highest concentrations 

corresponding to samples with the highest Pb concentrations. 

6.9.5 Lessons Learned with Regard to the Sampling and Analysis of Tire Crumb Materials 

Again, there are no validated sample collection and analytical procedures for 

characterizing tire crumb materials for assessing potential environmental concentrations or 

potential exposures by various routes and pathways at synthetic turf fields and playgrounds. An 

objective of this scoping study was to apply an existing wipe sample collection method and 

analytical procedures developed for soil media and to assess their performance. A few of the 

lessons learned are described below. 

• There was no evaluated protocol available for measuring tire crumb rubber constituents at turf 

fields and playgrounds. As such, this scoping study was conducted to evaluate the methods 

and identify key factors (e.g., resources, accessibility, practicality, activity levels) that would 

need to be considered in designing future studies. Some factors that may need to be 

considered for future research include the number and placement of sampling locations (i.e., 

how many samples at how many locations need to be collected and analyzed to adequately 

characterize a site), representative and duplicate wipe samples for turf fields with mixed 

colors, retaining or not retaining turf infill and fibers on wipe samples, representative material 

samples, the relationship between the wipe sample and material sample results. 

• In some cases, the amount of material available for analysis was not optimal, generally a 1-g 

sample is specified in methods. For tire crumb material from playgrounds, most of the crumb 

pieces were much larger than 1 g. It was decided that the material would not be cut because 

that would open fresh surfaces that potentially would result in different extractable amounts. 

Decisions not to cut up samples prevented sample size matching to extraction procedure 

requirements and prevented homogenization procedures. In addition, the larger samples 

created some extraction and analysis problems with regard to the extraction vessel and need 

for multiple dilutions of some sample extracts. On the other hand, some samples of synthetic 

turf blades collected in this study were not adequate for analysis. Only nondestructive 

collection of loose blades was performed in this study. In future work, sample sizes and 

decisions regarding tire crumb subsampling should be considered. 

• Information from this and other studies regarding the metals of most interest would improve 

analytical optimization, reporting, and the selection of appropriate QC materials. 

• The heterogeneity of these samples create analysis and data interpretation challenges. For 

example, multiple dilutions and reanalyses of many samples were required to obtain 

measurements in the instrument calibration range. Based on excellent results from analytical 

QC analyses (serial dilution and postdigestion spikes), the new ICP/MS instrument used for 

this study appeared to produce quantitative total extractable results for the wipe samples, turf 

blades, tire infill, and tire crumb media for multiple metals with low detection limits. 

• Spiking levels appropriate to the tire material and blade material concentrations need to be 

considered in future study designs to improve results. However, given the heterogeneity of 

the materials, it is not clear whether spiking samples to assess recoveries will be feasible. 

Spike recoveries need to be reevaluated with truly homogeneous samples to determine 

whether the extraction procedure or the sample heterogeneity was the source of variable 

recoveries during the scoping study. 

• Sporadic contamination of laboratory bottle blanks was found, especially for metals that might 

be associated with steel. In this study, the blank result for each analysis batch was subtracted 

from measured results, following the standard procedure. In the future, blank correction could 

be based on the average of the bottle blanks, with the option of removing outliers. 

38
Investigation is needed of possible sources of contamination and, perhaps, changing to a less 

“open” extraction process. 

6.10 Pb Bioaccessibility Results (Appendix C, Tables C-9, C-10, and C-11) 

6.10.1 Analysis of Turf Field Wipe, Tire Crumb, and Turf Blade Samples 

The bioaccessible values for Pb in the field samples are provided in Appendix C.

Because of the variability observed for different sample aliquots, duplicate samples, and 

analyses of multiple sample pieces, we have reported all analyses individually rather than 

averaging the results across the two measurements for each sample. It is important to 

recognize that different bioaccessibility procedures may yield different Pb bioaccessibility 

results. The EPA method employed in this study has been validated for Pb in soil, but no 

methods have been validated for tire crumb or synthetic turf blade materials. Highlights from the 

bioaccessability analyses include those below. 

• Synthetic turf field tire crumb infill Pb bioaccessibility ranged from 1.6% to 10.7% (mean 4.7%; 

Table C-9). 

• Synthetic turf field blade Pb bioaccessibility (Table C-10) ranged from 0.2% to 86.8% (mean 

34.2%). The three samples with the highest total extractable Pb (77 to 700 μg/g) had the 

lowest Pb bioaccessibility values (0.2% to 2.3%). Gaining a clear understanding of this 

observation requires additional research. 

• Playground tire crumb Pb bioaccessibility (Table C-11) ranged from 0.3% to 7.4% (mean 

4.3%). The two samples with the highest total extractable Pb (46 and 440 μg/g) had the 

lowest Pb bioaccessibility values (both 0.3%). Gaining a clear understanding of this 

observation requires additional research. 

• Up to a fourfold difference in Pb bioaccessibility was found between two aliquots of tire crumb 

infill analyzed from the same sample vial. Up to a 36-fold difference was found between the 

analyses of seven pieces of tire crumb material from the same playground. These results 

suggest substantial heterogeneity in Pb bioaccessibility from tire crumb rubber samples. 

Gaining a clear understanding of this observation requires additional research. 

• The in vitro Pb bioaccessibility method was judged to be inappropriate for the surface wipe 

samples. The blank media bioaccessible Pb values were similar to the values observed in the 

field samples. Given the relatively small amount of dust collected on the wipe, as compared 

with the large mass of wipe material, and the relatively low amounts of Pb measured, it is 

likely that any calculated bioaccessibility attributed to the dust likely is to be impacted 

significantly by the background levels in the sampling and analysis procedures. Gaining a 

clear understanding of this observation requires additional research. 

6.10.2 Lessons Learned with Regard to Bioaccessibility Data 

An objective of this scoping study was to apply existing wipe collection and material 

analytical procedures developed for soil media and to assess their performance. A few of the 

lessons learned are described below. 

• Sufficient quantities of samples are needed to meet extraction requirements for EPA SOP 

9200.1-86; this should be considered in sampling designs. 

• Limitations on cutting samples prevented further homogenization of samples. 

• Better method detection limits (MDLs) for the in vitro extractions were achieved relative to the 

EPA SOP 9200.1-86 requirements and values previously published.

• Additional methods development and validation research is recommended before this wipe 

method is applied in future studies. 

39
6.11 Methods Evaluation Summary 

A summary evaluation of the sample collection and analysis methods for the several 

types of samples collected in this scoping study is provided in Table 9. 

40
Table 9. Overall Summary and Assessment of Methods Applied in This Scoping Study

Sample Type Sample Collection Sample Analysis Other Comments 

Air VOCs • Grab samples simple to 

collect. 

• Short time needed. 

• Can be collected directly 

over field or playground. 

• Standard Method TO-15 

(GC/MS) provided data for 

56 analytes with good 

precision and accuracy. 

• Sensitivity was sufficient to 

measure analytes in ambient 

air. 

• Overall, this method 

was simple to 

implement and provided 

adequate data. 

Air PM10 

(mass, metals, 

SEM) 

• Large amount of 

equipment needed. 

• Technical expertise 

required. 

• Required 8-10 h of time 

to collect. 

• Could not always be 

placed directly on field 

because of activity. 

• Standard research methods 

provided data for mass 

concentration and for 

multiple metals. 

• Sensitivity sufficient to 

measure analytes in ambient 

air. 

• Precision and accuracy were 

good. 

• Overall, this method 

was somewhat complex 

and time consuming to 

implement and provided 

adequate data. 

• Identification of tire 

crumb particles was 

difficult because of lack 

of standard morphology 

or composition. 

Surface Wipes 

(turf fields) 

• Moderately simple to 

collect. 

• Short time needed. 

• Method not validated for 

synthetic turf surfaces. 

• Wipes can collect infill 

particles and turf blades 

(that were removed for 

these analyses). 

• Standard EPA Methods 

3050B and 6020 applied with 

good recovery and analytical 

precision. 

• Sensitivity was very good 

and sufficient to measure low 

levels of multiple metals. 

• EPA Pb in vitro 

bioaccessibility method 

9200.1-86 found not to be 

appropriate for wipe 

samples. 

• Overall, this method 

was relatively simple to 

implement. 

• The method provided 

quantitative 

measurement results, 

but the method has not 

been validated for use 

on synthetic turf field 

surfaces. 

• The in vitro Pb 

bioaccessibility method 

was judged to be 

inappropriate for the 

surface wipe samples. 

Tire Crumb 

Infill (turf fields) 

• Simple to collect. 

• Short time needed. 

• Decisions needed on 

area and depth of 

material collection. 

• Standard EPA Methods 

3050B and 6020 applied with 

good analytical precision. 

• EPA Pb in vitro 

bioaccessibility method 

9200.1-86 applied with good 

analytical precision. 

• Nonhomogeneous material 

made assessment of analyte 

recoveries difficult. 

• Sensitivity was very good 

and sufficient to measure low 

levels of multiple metals. 

• Overall, this method 

was relatively simple to 

implement. 

• The method provided 

quantitative 

measurement results, 

but the method has not 

been validated for use 

on tire crumb particles. 

• Improved quality control 

methods and materials 

required to assess 

metal recoveries. 

• Nonhomogeneity of Pb 

has implications for site 

sampling, analysis, and 

data interpretation. 

41
Table 9. Overall Summary and Assessment of Methods Applied in This Scoping Study 

(cont’d.)

Sample Type Sample Collection Sample Analysis Other Comments 

Blades 

(turf fields) 

• Simple to collect. 

• Relatively short time 

needed. 

• Limited in this study to 

collecting loose blades 

where available. 

• Larger sample size 

needed for analysis (>1 g 

each) than were collected 

for some samples in this 

study. 

• Collection of different 

colors revealed different 

Pb levels at some fields; 

this should be considered 

in site sampling plans. 

• Standard EPA Methods 

3050B and 6020 applied 

with good analytical 

precision. 

• EPA Pb in vitro 

bioaccessibility method 

9200.1-86 applied with 

good analytical 

precision. 

• Nonhomogeneous 

material made 

assessment of analyte 

recoveries difficult. 

• Sensitivity was very 

good and sufficient to 

measure low levels of 

multiple metals of 

interest. 

• Overall, this method 

was relatively simple to 

implement. 

• The method provided 

quantitative 

measurement results, 

but the method has not 

been validated for use 

on synthetic turf blades. 

• Improved quality control 

methods and materials 

required to assess 

metal recoveries. 

• Differences for Pb 

depending on blade 

color have implications 

for site sampling and 

analysis. 

Tire Crumb 

Rubber 

(playgrounds) 

• Simple to collect. 

• Short time needed. 

• Decisions required on site 

sampling plan with regard 

to location and number of 

areas and depth of 

material for collection. 

• Standard EPA Methods 

3050B and 6020 applied 

with good analytical 

precision. 

• EPA Pb in vitro 

bioaccessibility method 

9200.1-86 applied with 

good analytical 

precision. 

• Sensitivity was very 

good and sufficient to 

measure low levels of 

multiple metals of 

interest. 

• Nonhomogeneous 

material made 

assessment of analyte 

recoveries difficult. 

• Tire crumb pieces were 

larger than the 1 g 

desired for analysis; 

homogenization and 

subsampling may be 

needed in future work. 

• Overall, sample 

collection was simple to 

implement, but analysis 

was more difficult 

because of sample size 

issues. 

• The method provided 

quantitative 

measurement results, 

but the method has not 

been validated for use 

on tire crumb particles. 

• Improved quality control 

methods and materials 

required to assess 

metal recoveries. 

• Nonhomogeneity of Pb 

has implications for site 

sampling, analysis, and 

data interpretation. 

42
7. References 

Chen, F., Williams, R., Svendsen, E., Yeatts, K., Creason, J., Scott, J., Terrell, D., Case. M. (2007). 

Coarse particulate matter concentrations from residential outdoor sites associated with the North 

Carolina Asthma and Childrens Environment Studies (NC-ACES). Atmospheric Environment, 

41:1200-1208. 

National Research Council (2003). Bioavailability of Contaminants in Soils and Sediments: Processes, 

Tools, and Applications. National Academies Press: Washington, DC. 

http://www.nap.edu/openbook/0309086256/html/. 

U.S. EPA (2008). Quality Assurance Project Plan. Scoping Study: Evaluation of Exposure Methods and 

Approaches for Characterizing Environmental Concentrations Resulting from the Use of Tire 

Crumb Components in Playgrounds and Artificial Turf Fields. National Exposure Research 

Laboratory. 

Williams, R., Suggs, J., Rea., A., Leovic, K., Vette, A., Croghan, C., Sheldon, L., Rodes, C., 

Thornburg, J., Ejire, A., Herbst, M., Sanders, W. Jr. (2003). The Research Triangle Park 

particulate matter panel study: PM mass concentration relationships. Atmospheric Environment, 

37:5349-5363. 

Williams, R., Rea, A., Vette, A., Croghan C., Whitaker, D., Wilson, H., Stevens, C., McDow, S., Burke, J., 

Fortmann, R., Sheldon, L., Thornburg, J., Phillips, M., Lawless, P., Rodes, C., Daughtrey, H. 

(2008). The design and field implementation of the Detroit Exposure and Aerosol Research Study 

(DEARS). Journal of Exposure Science and Environmental Epidemiology, doi:101038. 

43
Appendix A

List of Sample Collection and Analysis Methods 

NOTE: The following methods have not been evaluated for collecting and analyzing samples 

from synthetic turf fields or from playgrounds with tire crumb rubber. 

Research Operating Procedure for the Collection of Particulate Matter (PM) Air Samples at 

Playgrounds and Synthetic Turf Fields 

Research Operating Procedure for the Collection of Tire Crumb Material at Playgrounds 

Research Operating Procedure for the Collection of “Grass Blade” Fibers from Synthetic Turf 

Fields 

Research Operating Procedure for the Collection of Infill Material from Synthetic Turf Fields 

Research Operating Procedure for the Collection of Volatile Organic Chemicals in Air Using 

Canisters 

ASTM E1792-03: Standard Specification for Wipe Sampling Materials for Lead in Surface Dust 

ASTM E1728-03: Standard Practice for Collection of Settled Dust Samples Using Wipe 

Sampling Methods for Subsequent Lead Determination 

Recommended Operating Procedure for Elemental Analysis of Particulate Matter on Membrane 

Filters by the LBL XRF Spectrometer 

Standard Operating Procedure for the Gravimetric Determination of Particle Mass on Teflon Air 

Sampling Filters 

Standard Operating Procedures for the USEPA-NERL Scanning Electron Microscopy/ 

Energy-Dispersive X-Ray Analysis (SEM/EDX) Laboratory 

Compendium Method TO-15: Determination of Volatile Organic Compounds (VOCs) in Air 

Collected in Specially-Prepared Canisters and Analyzed by Gas Chromatography/Mass 

Spectrometry (GC/MS); (Region 1 EIASOP-AIRCAN9: “Standard Operating Procedure for the 

Analysis of Volatile Organic Compounds in Air by Gas Chromatography/Ion Trap Detector)” 

EPA SW-846 Method 3050B: Acid Digestion of Sediments, Sludges, and Soils. Revision 2. 

December 1996 

EPA SW-846 Method 6020A: Inductively Coupled Plasma-Mass Spectrometry. Revision 1. 

February 2007 

EPA 9200.1-86. Standard Operating Procedure for an In Vitro Bioaccessibility Assay for Lead in 

Soil. May 2008 

44
Appendix B

Quality Control and Quality Assurance Results 

Table B-1. Field and Laboratory Blank Measurement Results for Volatile Organic Compounds in 

Air 

Table B-2. Percent Recovery of Air Volatile Organic Compounds in Field and Laboratory 

Controls 

Table B-3. Relative Percent Difference in Measurement Results for Air Volatile Organic 

Compounds in Field Duplicate Canister Samples and in Repeat Analysis of Canister Samples in 

the Laboratory 

Table B-4. ICP/MS Operating Parameter Settings 

Table B-5. ICP/MS Isotopes and Interference Corrections 

Table B-6. Concentrations of Individual Metals in Working Calibration Standards 

Table B-7. ICP/MS Method Detection Limits 

Table B-8. Summary of ICP/MS QC Criteria 

Table B-9. Summary of ICP/MS Instrumental QC Results 

Table B-10. Recovery of Metals Spiked in Extraction Reagent Blank 

Table B-11. Recovery of Metals-Spiked Solution on Matrix of Interest 

Table B-12. Total Extractable Recoveries for NIST SRM 2710 Spiked into Extraction Solution 

Table B-13. Total Extractable Recoveries for NIST SRM 2710 Spiked onto Ghost Wipe Media 

Table B-14. Bottle Blank Data Used for Sample Correction and Reagent Blank Data Method 

3050B 

Table B-15. Laboratory and Field Ghost Wipe Blank Samples 

Table B-16. Relative Percent Differences for the Analysis of Duplicate Aliquots of Tire Crumb 

Infill from Synthetic Fields and Playground Tire Crumb Samples 

Table B-17. Recommended Control Limits for In Vitro Soil Quality Control Samples According to 

EPA Method 9200.1-86 

Table B-18. Summary Control Limit Results for In Vitro Pb Bioaccessibility Quality Control 

Samples 

Table B-19. Percent Recovery Results for In Vitro Blank Spikes 

45
46

Table B-20. Summary of Pb In Vitro Extractable Values for NIST SRM 2710 

Table B-21. Summary of Pb In Vitro Extractable Values for NIST SRM 2710 Spiked onto Ghost 

Wipe Media 

Table B-22. Results for In Vitro Pb Solution Spikes onto Blank Ghost Wipes and Tire Crumb 

Samples 

Table B-23. In Vitro Pb Bioaccessibility Extraction Duplicates for Synthetic Turf Field Tire Crumb 

Infill 

Table B-24. In Vitro Pb Bioaccessibility Extraction Duplicates for Playground Tire Crumb 
47

Table B-1. Field and Laboratory Blank Measurement Results (ppbV) for Volatile Organic Compounds (VO

Field Blanks Laboratory Bl

VOC 

Field Blank 

MDL 

Sample 

MDL P1 F4 F1D1 P1 F2 F4 

1,1,1-Trichloroethane 0.05 0.076a NDb ND ND ND ND ND 1,1,2,2-Tetrachloroethane 0.05 0.076a ND ND ND ND ND ND 1,1,2-Trichloroethane 0.05 0.076a ND ND ND ND ND ND 1,1-Dichloroethane 0.05 0.076a ND ND ND ND ND ND 1,1-Dichloroethylene 0.05 0.076a ND ND ND ND ND ND 1,2,4-Trichlorobenzene 0.05 0.076a ND ND ND ND ND ND 1,2,4-Trimethylbenzene 0.05 0.076a ND ND 0.360 ND ND ND 1,2-Dibromoethane 0.05 0.076a ND ND ND ND ND ND 1,2-Dichlorobenzene 0.05 0.076a ND ND ND ND ND ND 1,2-Dichloroethane 0.05 0.076a ND ND 0.073 ND ND ND 1,2-Dichloropropane 0.05 0.076a ND ND ND ND ND ND 1,3,5-Trimethylbenzene 0.05 0.076a ND ND 0.120 ND ND ND 1,3-Butadiene 0.10 0.15c ND ND 0.250 ND ND ND 1,3-Dichlorobenzene 0.05 0.076a ND ND ND ND ND ND 1,4-Dichlorobenzene 0.05 0.076a ND ND ND ND ND ND 2-Hexanone 0.05 0.076a ND ND ND ND ND ND 4-Ethyltoluene 0.05 0.076a ND ND 0.380 ND ND ND Acrylonitrile 0.05 0.076a ND ND ND ND ND ND Allyl Chloride 0.05 0.076a ND ND ND ND ND ND Benzene 0.05 0.076a ND ND 1.11 ND ND ND Benzylchloride 0.05 0.076a ND ND ND ND ND ND Bromodichloromethane 0.05 0.076a ND ND ND ND ND ND Bromoform 0.05 0.076a ND ND ND ND ND ND c-1,2-Dichloroethylene 0.05 0.076a ND ND ND ND ND ND c-1,3-Dichloropropylene 0.05 0.076a ND ND ND ND ND ND Carbon Tetrachloride 0.05 0.076a ND ND 0.040 ND ND ND Chlorobenzene 0.05 0.076a ND ND 0.510 ND ND ND Chloroethane 0.05 0.076a ND ND ND ND ND ND Chloroform 0.05 0.076a ND ND 0.049 ND ND ND Cyclohexane 0.05 0.076a ND ND 12.0 ND ND ND Dibromochloromethane 0.05 0.076a ND ND ND ND ND ND Dichlorodifluoromethane 0.05 0.076a ND ND 0.270 ND ND ND Dichlorotetrafluoroethane 0.05 0.076a ND ND ND ND ND ND Ethylbenzene 0.05 0.076a ND ND 1.63 ND ND ND Heptane 0.05 0.076a ND ND ND ND ND ND Hexachloro-1,3-butadiene 0.05 0.076a ND ND ND ND ND ND Hexane 0.05 0.076a ND ND 6.20 ND ND ND m&p-Xylenes 0.10 0.15c ND ND 4.27 ND ND ND Methyl Ethyl Ketone 0.05 0.076a 0.100 0.059 3.83 0.040 0.044 ND 
48

Table B-1. Field and Laboratory Blank Measurement Results (ppbV) for Volatile Organic Compounds (VO

Field Blanks Laboratory B

VOC 

Field Blank 

MDL 

Sample 

MDL P1 F4 F1D1 P1 F2 F4 

Methyl Isobutyl Ketone 0.05 0.076a ND ND 0.190 ND ND ND Methylbromide 0.05 0.076a ND ND 0.042 ND ND ND Methylchloride 0.05 0.076a ND ND 0.440 ND ND ND Methylene Chloride 0.05 0.076a ND ND 0.400 ND ND ND Methyl-t-butyl ether 0.05 0.076a ND ND ND ND ND ND o-Xylene 0.05 0.076a ND ND 1.35 ND ND ND Styrene 0.05 0.076a ND ND 1.10 ND ND ND t-1,2-Dichloroethylene 0.05 0.076a ND ND ND ND ND ND t-1,3-Dichloropropylene 0.05 0.076a ND ND ND ND ND ND Tetrachloroethylene 0.05 0.076a ND ND 0.160 ND ND ND Tetrahydrofuran 0.05 0.076a ND ND ND ND ND ND Toluene 0.05 0.076a ND ND 29.0 ND ND ND Trichloroethylene 0.05 0.076a ND ND 0.180 ND ND ND Trichlorofluoromethane 0.05 0.076a ND ND ND ND ND ND Trichlorotrifluoroethane 0.05 0.076a ND ND ND ND ND ND Vinyl Bromide 0.05 0.076a ND ND ND ND ND ND Vinylchloride 0.05 0.076a ND ND ND ND ND ND 

a Range from 0.070 to 0.079 ppbV. bND = not detected. c Range from 0.14 to 0.16 ppbV. 
Table B-2. Percent Recoverya

 of Air Volatile Organic Compounds (VOCs) in Field and 

Laboratory Controls 

Field Controls Laboratory Controls 

VOC 

Spiking 

Level 

(ppbV) P1 F4 F1D1 Mean 

Std. 

Dev. P1 F4 F1D2 Mean 

Std. 

Dev. 

1,1,1-Trichloroethane 4.83 124 114 136 125 10.8 120 125 128 124 4.3 

1,1,2,2-Tetrachloroethane 4.99 98 86 99 94 7.5 93 93 93 93 0.1 

1,1,2-Trichloroethane 4.82 112 104 119 112 7.8 108 110 109 109 1.1 

1,1-Dichloroethane 4.90 112 99 108 106 6.8 106 99 93 99 6.2 

1,1-Dichloroethylene 4.78 103 97 122 108 12.8 106 101 109 105 3.9 

1,2,4-Trichlorobenzene 4.09 72 44 70 62 15.7 69 61 70 66 5.0 

1,2,4-Trimethylbenzene 5.04 101 84 102 96 10.1 96 98 96 97 1.2 

1,2-Dichlorobenzene 4.97 91 77 91 86 8.4 88 85 86 86 1.7 

1,2-Dichloropropane 4.85 112 105 119 112 6.7 102 114 109 108 5.8 

1,3,5-Trimethylbenzene 4.87 111 97 112 107 8.8 111 108 109 109 1.3 

1,3-Dichlorobenzene 5.00 92 77 92 87 8.5 89 83 86 86 2.9 

Benzene 4.83 116 105 120 114 7.7 114 118 111 114 3.5 

c-1,2-Dichloroethylene 4.80 107 97 113 106 8.1 106 99 99 101 3.9 

Carbon Tetrachloride 4.84 101 26 132 87 55.0 76 107 120 101 22.7 

Chlorobenzene 4.86 103 97 105 101 4.4 102 102 104 102 1.3 

Chloroethane 4.81 96 66 112 91 23.2 90 101 91 94 6.1 

Chloroform 4.90 110 99 106 105 5.8 103 104 96 101 4.6 

Dichlorodifluoromethane 4.05 113 95 107 105 9.0 97 95 101 98 3.0 

Dichlorotetrafluoroethane 3.84 103 96 109 103 6.6 100 104 99 101 2.5 

Ethylbenzene 4.88 79 94 109 94 15.0 84 104 105 97 12.0 

Hexachloro-1,3-butadiene 4.41 92 72 89 84 10.7 90 81 103 91 11.1 

m&p-Xylenes 4.97 106 95 111 104 8.3 106 108 106 107 1.0 

Methylchloride 4.38 90 103 98 97 6.5 89 87 82 86 3.8 

Methylene Chloride 4.91 111 101 114 108 6.7 105 105 101 104 2.4 

o-Xylene 4.60 108 93 111 104 9.7 102 105 104 104 1.2 

Tetrachloroethylene 4.86 109 100 108 106 5.0 101 107 105 104 3.0 

Toluene 4.83 107 101 115 108 7.1 107 108 108 108 0.3 

Trichloroethylene 4.92 113 103 112 109 5.3 98 107 109 105 5.5 

Trichlorofluoromethane 4.76 117 106 120 114 7.3 114 116 110 113 3.1 

Vinylchloride 3.09 104 97 116 106 9.2 103 105 102 103 1.4 

a │ Found │ a │ Expected │ * 100 

49
Table B-3. Relative Percent Difference (RPD)a

 in Measurement Results for Air Volatile 

Organic Compounds (VOCs) in Field Duplicate Canister Samples and in Repeat Analysis 

of Canister Samples in the Laboratory 

Field Duplicates Laboratory Repeat Analysis 

RPD RPD RPD Mean 

Std. 

Dev RPD RPD RPD Mean 

Std. 

Dev. 

VOC P1 F4 F1D1 RPD RPD P1 F4 F1D1 RPD RPD 

Benzene 4.8 13.3 9.5 9.2 4.3 12.8 0.0 7.9 6.9 6.4 

Carbon Tetrachloride 9.3 3.4 8.3 7.0 3.1 12.4 1.1 1.0 4.9 6.6 

Dichlorodifluoromethane 3.8 0.0 7.7 3.8 3.8 1.9 4.1 5.6 3.9 1.9 

Hexane 44.9 28.6 105.5 59.7 40.5 ― 0.0 31.2 15.6 22.1 

m&p-Xylenes ― 2.6 74.2 38.4 50.6 ― 8.7 3.7 6.2 3.5 

Methyl Ethyl Ketone 11.8 4.8 28.6 15.0 12.2 0.0 2.0 14.6 5.6 7.9 

Methyl Isobutyl Ketone ― ― 21.1 21.1 ― ― ―

Methylchloride 8.5 2.1 4.1 4.9 3.3 0.0 0.0 8.7 2.9 5.0 

Methylene Chloride 44.4 20.3 ― 32.4 17.0 4.3 8.7 12.0 8.3 3.8 

Toluene 107.1 6.5 143.9 85.8 71.1 6.9 5.4 30.8 14.4 14.2 

Trichlorofluoromethane 0.0 0.0 11.3 3.8 6.5 0.0 0.0 11.3 3.8 6.5 

Trichlorotrifluoroethane 2.7 1.4 1.2 1.8 0.8 2.7 2.8 7.7 4.4 2.8 a

100 * ABS(M1- M2) / [(M1+M2) / 2}

50
Table B-4. ICP/MS Operating Parameter Settings 

Instrument Settings 

RF Power 1,200-1,260 W 

Ar Gas Flow Rates: 

 Cool 13 Lpm 

 Auxiliary 0.9-1.0 Lpm 

CCT Gas Flow (He 93%/ H 7%) ~10 μL/min 

Sampler Cone (Ni/Cu) 1.1-mm diameter orifice sample cone 

Skimmer Cone (Ni/Cu) 0.75-mm diameter skimmer cone 

Nebulizer Concentric nebulizer, 35 PSI, 1 mL/min 

Spray Chamber Air-cooled cyclone 

Detector Dead Time 55 ns 

Internal Standard Solution 40-200 ppb solution of 6 Li 45 Sc 89 Y In115 and 159Tb 

Acquisition Parameters (Normal Mode)

Major Minor Global Add. Gases 

Extraction Lens Standard resolution CCT – 0 

Lens 1 Forward power 1,400 High resolution 

Lens 2 Horizontal Analogue detector 

Focus Vertical PC detector 

D1 DA 

D2 -140 Cool 

Pole Bias 0 Auxiliary 

Hexapole Bias -4.0 Sampling depth 130-140 

Acquisition Parameters (Collision Cell Technology [CCT] Mode)

Major Minor Global Add. Gases 

Extraction Lens Standard resolution CCT – ~10 μL/min

Lens 1 Forward power 1,400 High resolution 

Lens 2 Horizontal Analogue detector 

Focus Vertical PC detector 

D1 DA 

D2 -140 Cool 

Pole Bias -17.0 Auxiliary 

Hexapole Bias -20.0 Sampling depth 130-140 

Operating Parameters 

Standard Resolution 0.75 ± 0.1 amu 

High Resolution 0.30 ± 0.1 amu 

Integration Type Average 

Calibration Type Linear 

Number of scans per replicate 1 

Number of replicates (runs) 3-7 

51
Table B-5. ICP/MS Isotopes and Interference Corrections 

Analyte Mass Interference Analyte Mass Interference 

Pb 207 Cd 114 -0.027 * 118 Sn 

Pb 208 Cu 65 

Cr 52 Fe 54 -0.028 * 52 Cr 

Zn 66 Fe 56 -0.15 * 43 Ca 

Al 27 Mn 55 

As 75 Ni 60 -0.002 * 34 Ca 

Ba 137 Ni 62 

Cd 111 

Table B-6. Concentrations of Individual Metals in Working Calibration Standards

Metal 

LoCal1 

(ppb) 

LoCal2 

(ppb) 

HiCal1 

(ppm) 

HiCal2 

(ppm) 

LLQC CRI 

(ppb) 

LoCal3 

(ppb) 

LoCal2 

1:100 (ppb)

Pb 250 500 1 1,000 5 

Cr 250 500 2 1,000 5 

Zn 250 500 2 1,000 5 

Al 250 500 30 1,000 5 

As 250 500 1 1,000 5 

Ba 250 500 10 1,000 5 

Cd 250 500 1 1,000 5 

Cu 250 500 2 1,000 5 

Fe 250 500 50 100 1,000 5 

Mn 250 500 1 1,000 5 

Ni 250 500 1 1,000 5 

Internal 

Standards 

Li 200 

Sc 200 

Y 40 

In 40 

Tb 40 

Table B-7. ICP/MS Method Detection Limits (ppb)a

Metal Isotope In Vitro Method EPA Method 3050B 

Pb 208 0.082 0.092 

Cr 52 0.201 0.175 

Zn 66 0.409 0.388 

Al 27 1.99 2.47 

As 75 0.366 0.246 

Ba 137 0.668 0.634 

Cd 111 0.219 0.224 

Cu 65 0.335 0.350 

Fe 56 6.4 4.3 

Mn 55 0.178 0.144 

Ni 60 0.268 0.332 a

Calculated by formula in 40 CRF Part 136. MDLs reported here are for sample extracts delivered to the instrument. 

For In vitro matrix: First CRI chosen per day over 6 analysis days plus 1 extra. (Note: One metal (Fe) not spiked into 

CRI so concentration at reagent blank level. 

For EPA 3050B matrix: One CRI chosen per day over 7 analysis days. 

52
Table B-8. Summary of ICP/MS QC Criteriaa

Name Acceptance Criteria 

Minimum Value 

Requirement 

Initial Calibration Verification 90%-110% 

 Initial Calibration Blank <CRQLb

 Continuing Calibration Verification 90%-110% 

 Continuing Calibration Blank <CRQL 

 Interference Check Solution A 

±3CRQL or ±20% 

true value 

 Interference Check Solution AB 

±3CRQL or ±20% 

true value 

 Contract Required Quantitation Limit Check 

±30%, except ±50% 

for Co, Mn, Zn 

 Duplicate Samples Relative Percent Difference <20% 50 times CRQL 

 Serial Dilution Samples Percent Difference <10% 50 times CRQL 

 Post Digestion Spike Samples 75%-125% 

Sample Extract QC 

 Spike 75%-125% 

 SRM 75%-125% a

Based on EPA Method 6020A QC criteria. 

b

CRQL = contract required quantitation limit. 

53
Table B-9. Summary of ICP/MS Instrumental QC Results

In EPA 3050B 5% HNO3 Matrix, n=4

Metal Mass 

(amu) DUPa

 Criteria DUP RPDb Found Status (pass/fail) 

Pb 208 <20% 0.117%-7.83% P 

Cr 52 <20% 0.145%-3.54% P 

Zn 66 <20% 0.081%-1.26% P 

Al 27 <20% 0.023%-5.26% P 

As 75 <20% 0.929%-12.8% P 

Ba 137 <20% 0.563%-1.41% P 

Cd 111 <20% 1.048%-1.26% P 

Cu 65 <20% 0.011%-1.40% P 

Fe 56 <20% 0.110%-2.37% P 

Mn 55 <20% 1.09%-3.61% P 

Ni 60 <20% 0.478%-2.50% P 

Metal Mass 

(amu) SERc

 Criteria SER Difference Status (pass/fail) 

Pb 208 <10% 2.54%-7.24% P 

Cr 52 <10% 0.167% P 

Zn 66 <10% 2.41%-7.74%, 14.8% F 

Al 27 <10% 1.50%-4.31% P 

As 75 <10% *

d N/A 

Ba 137 <10% 0.938%-4.99% P 

Cd 111 <10% * N/A 

Cu 65 <10% 2.34%-5.72% P 

Fe 56 <10% * N/A 

Mn 55 <10% * N/A 

Ni 60 <10% 3.43% P 

Metal Mass 

(amu) PDSe

 Criteira PDS Recovery Status (pass/fail) 

Pb 208 75%-125% 100%-104% P 

Cr 52 75%-125% 86.7%-89.0% P 

Zn 66 75%-125% 99.6%-109% P 

Al 27 75%-125% * N/A 

As 75 75%-125% 98.7%-105% P 

Ba 137 75%-125% 77.2%-100% P 

Cd 111 75%-125% 94.6%-103% P 

Cu 65 75%-125% 96.5%-101% P 

Fe 56 75%-125% * N/A 

Mn 55 75%-125% * N/A 

Ni 60 75%-125% 92.8%-99.2% P 

 

54
Table B-9. Summary of ICP/MS Instrumental QC Results (cont’d.)

In In Vitro 2% HNO3 Matrix, n=5

Metal Mass 

(amu) DUP Criteria DUP RPD Found Status (pass/fail) 

Pb 208 <20% 0.684%-4.70% P 

Cr 52 <20% * N/A 

Zn 66 <20% 0.104%-1.98% P 

Al 27 <20% 1.90%-11.0% P 

As 75 <20% * N/A 

Ba 137 <20% 0.142%-2.38% P 

Cd 111 <20% * N/A 

Cu 65 <20% 0.142%-9.38% P 

Fe 56 <20% * N/A 

Mn 55 <20% * N/A 

Ni 60 <20% * N/A 

Metal Mass 

(amu) SER Criteria SER Difference Status (pass/fail) 

Pb 208 <10% 0.062% P 

Cr 52 <10% * N/A 

Zn 66 <10% 0.169%-9.40% P 

Al 27 <10% 8.49%, 26.0% F 

As 75 <10% * N/A 

Ba 137 <10% 0.045%-2.51% P 

Cd 111 <10% * N/A 

Cu 65 <10% * N/A 

Fe 56 <10% * N/A 

Mn 55 <10% * N/A 

Ni 60 <10% * N/A 

Metal Mass 

(amu) PDS Criteria PDS Recovery Status (pass/fail) 

Pb 208 75%-125% 94.7%-106% P 

Cr 52 75%-125% 91.2%-102% P 

Zn 66 75%-125% 95.4%-110% P 

Al 27 75%-125% * N/A 

As 75 75%-125% 90.0%-103% P 

Ba 137 75%-125% 88.0%-108% P 

Cd 111 75%-125% 97.3%-107% P 

Cu 65 75%-125% 91.2%-111% P 

Fe 56 75%-125% * N/A 

Mn 55 75%-125% * N/A 

Ni 60 75%-125% 97.2%-108% P a

DUP = duplicate aliquot of extract analyzed independently. 

b

RPD = relative percent difference. 

c

SER = serial dilution of extract. d

Concentrations too low to meet QC criteria. 

e

PDS = postdigestion spike. 

55
Table B-10. Recovery of Metals Spiked in Extraction Reagent Blank 

Sample ID Description 

Spiked Amount 

(total ug spiked) 

Net Total Extractable 

(total ug found) 

Percent 

Recovery 

Primary Metals of Interest 

Cr 

TC1-2 Blank Spike 640 600 93.7 

TC2-2 Blank Spike 640 616 96.3 

TC3-2 Blank Spike 2,500 2,340 93.8 

TC4-2 Blank Spike 2,500 2,350 94.1 

TC5-2 Blank Spike 2,500 2,320 92.7 

TC6-2 Blank Spike 2,500 2,390 95.8 

TC7-2 Blank Spike 2,500 2,370 94.8 

TC8-2 Blank Spike 2,500 2,380 95.0 

X (n=8) 94.5 

Pb 

TC1-2 Blank Spike 1,000 949 94.9 

TC2-2 Blank Spike 1,000 1,070 107 

TC3-2 Blank Spike 1,000 987 98.7 

TC4-2 Blank Spike 1,000 985 98.5 

TC5-2 Blank Spike 1,000 980 98.0 

TC6-2 Blank Spike 1,000 974 97.4 

TC7-2 Blank Spike 1,000 999 99.9 

TC8-2 Blank Spike 1,000 1,000 100 

X (n=8) 99.3 

Zn 

TC1-2 Blank Spike 800 774 96.8 

TC2-2 Blank Spike 800 747 93.4 

TC3-2 Blank Spike 2,500 2,390 95.7 

TC4-2 Blank Spike 2,500 2,390 95.5 

TC5-2 Blank Spike 2,500 2,370 94.8 

TC6-2 Blank Spike 2,500 2,420 96.7 

TC7-2 Blank Spike 2,500 2,400 95.9 

TC8-2 Blank Spike 2,500 2,400 96.1 

X (n=8) 95.6 

Secondary Metals of Interest 

Al 

TC1-2 Blank Spike 0 5.40 Not spiked 

TC2-2 Blank Spike 0 31.4 Not spiked 

TC3-2 Blank Spike 0.2 44.2 Not spiked 

TC4-2 Blank Spike 0.2 38.3 Not spiked 

TC5-2 Blank Spike 0.2 36.7 Not spiked 

TC6-2 Blank Spike 0.2 29.3 Not spiked 

TC7-2 Blank Spike 0.2 32.9 Not spiked 

TC8-2 Blank Spike 0.2 20.6 Not spiked 

X Not spiked 

As 

TC1-2 Blank Spike 0 23.1 Not spiked 

TC2-2 Blank Spike 0 22.9 Not spiked 

TC3-2 Blank Spike 500 449 89.8 

TC4-2 Blank Spike 500 459 91.8 

TC5-2 Blank Spike 500 449 89.8 

TC6-2 Blank Spike 500 423 84.5 

TC7-2 Blank Spike 500 453 90.6 

TC8-2 Blank Spike 500 463 92.5 

X (n=6) 89.8 

56
Table B-10. Recovery of Metals Spiked in Extraction Reagent Blank (cont’d.)

Sample ID Description 

Spiked Amount 

(total μg spiked) 

Net Total Extractable 

(total μg found) 

Percent 

Recovery 

Ba 

TC1-2 Blank Spike 0 2.97 Not spiked 

TC2-2 Blank Spike 0 4.58 Not spiked 

TC3-2 Blank Spike 2,510 2,420 96.6 

TC4-2 Blank Spike 2,510 2,460 98.1 

TC5-2 Blank Spike 2,510 2,420 96.3 

TC6-2 Blank Spike 2,510 2,480 98.6 

TC7-2 Blank Spike 2,510 2,490 99.2 

TC8-2 Blank Spike 2,510 2,490 99.1 

X (n=6) 98.0 

Cd 

TC1-2 Blank Spike 160 157 98.0 

TC2-2 Blank Spike 160 150 93.6 

TC3-2 Blank Spike 497 475 95.6 

TC4-2 Blank Spike 497 480 96.6 

TC5-2 Blank Spike 497 465 93.5 

TC6-2 Blank Spike 497 483 97.3 

TC7-2 Blank Spike 497 480 96.6 

TC8-2 Blank Spike 497 480 96.5 

X (n=8) 96.0 

Cu 

TC1-2 Blank Spike 800 793 99.1 

TC2-2 Blank Spike 800 800 100 

TC3-2 Blank Spike 2,540 2,410 95.0 

TC4-2 Blank Spike 2,540 2,410 95.0 

TC5-2 Blank Spike 2,540 2,400 94.6 

TC6-2 Blank Spike 2,540 2,450 96.3 

TC7-2 Blank Spike 2,540 2,420 95.4 

TC8-2 Blank Spike 2,540 2,430 95.5 

X (n=8) 96.4 

Fe 

TC1-2 Blank Spike 0 0 Not spiked 

TC2-2 Blank Spike 0 27.7 Not spiked 

TC3-2 Blank Spike 0 3.00 Not spiked 

TC4-2 Blank Spike 0 0.222 Not spiked 

TC5-2 Blank Spike 0 2.12 Not spiked 

TC6-2 Blank Spike 0 0.213 Not spiked 

TC7-2 Blank Spike 0 0.668 Not spiked 

TC8-2 Blank Spike 0 0.219 Not spiked 

X Not spiked 

Mn 

TC1-2 Blank Spike 400 377 94.2 

TC-2-2 Blank Spike 400 386 96.4 

TC3-2 Blank Spike 0.02 0.311 Not spiked 

TC4-2 Blank Spike 0.02 0.004 Not spiked 

TC5-2 Blank Spike 0.02 0.028 Not spiked 

TC6-2 Blank Spike 0.02 0 Not spiked 

TC7-2 Blank Spike 0.02 0.010 Not spiked 

TC8-2 Blank Spike 0.02 0.121 Not spiked 

X (n=2) 95.3 

57
58

Table B-10. Recovery of Metals Spiked in Extraction Reagent Blank (cont’d.)

Sample ID Description 

Spiked Amount 

(total μg spiked) 

Net Total Extractable 

(total μg found) 

Percent 

Recovery 

Ni 

TC1-2 Blank Spike 0 0.869 Not spiked 

TC-2-2 Blank Spike 0 0.312 Not spiked 

TC3-2 Blank Spike 1,250 1,220 97.2 

TC4-2 Blank Spike 1,250 1,220 97.7 

TC5-2 Blank Spike 1,250 1,200 95.8 

TC6-2 Blank Spike 1,250 1,240 99.2 

TC7-2 Blank Spike 1,250 1,220 97.5 

TC8-2 Blank Spike 1,250 1,230 98.3 

X (n=6) 97.6 
Table B-11. Recovery of Metals-Spiked Solution on Matrix of Interest 

Media and Sample 

Spiked 

Amount (μg) 

Net Spiked 

Total 

Extractable (μg) 

Net Media 

Total 

Extractable (μg) 

Media 

Corrected 

Spike (μg) 

Percent 

Recovery 

Pb on Wipes 

Blank Ghost Wipe 0.227 

Wipe with Spike 1,000 921 920 92.0 

Blank Ghost Wipe 0.694 

Wipe with Spike 991 994 993 100 

Blank Ghost Wipe 1.08 

Wipe with Spike 991 995 994 100 

Mean 99.4 

Pb on Infill 

F4-L1-S1-A1 41.1 

F4-L1-S1-A1 1,000 974 933 93.3 

F4-L1-D1-A1 24.8 

F4-L1-D1-A1 1,000 214 190 19.0 

F1-L3-S1-A1 20.6 

F1-L3-S1-A1 991 854 834 84.1 

F2-L2-D1-A1 36.4 

F2-L2-D1-A1 991 889 853 86.0 

Pb on Crumb 

P1-LA-TC1 0.989 

P1-LA-TC1 1,000 317 316 31.6 

P1-LA-TC2 6.31 

P1-LA-TC2 991 233 227 22.9 

P1-LB-TC1 443 

P1-LB-TC1 991 276 -167 N/A 

Cr on Wipes 

Blank Ghost Wipe 0.091 

Wipe with Spike 640 580 580 90.7 

Blank Ghost Wipe 6.24 

Wipe with Spike 2,490 2,400 2,390 96.1 

Blank Ghost Wipe 13.0 

Wipe with Spike 2,490 2,370 2,360 94.8 

Mean 93.9 

Cr on Infill 

F4-L1-S1-A1 0.602 

F4-L1-S1-A1 640 596 595 93.0 

F4-L1-D1-A1 0.352 

F4-L1-D1-A1 640 106 106 16.6 

F1-L3-S1-A1 0.544 

F1-L3-S1-A1 2,490 2,160 2,160 86.7 

59
Table B-11. Recovery of Metals-Spiked Solution on Matrix of Interest (cont’d.)

Media and Sample 

Spiked 

Amount (μg) 

Net Spiked 

Total 

Extractable (μg) 

Net Media 

Total 

Extractable (μg) 

Media 

Corrected 

Spike (μg) 

Percent 

Recovery 

F2-L2-D1-A1 0.018 

F2-L2-D1-A1 2,490 2,080 2,080 83.6 

Mean 69.9 

Cr on Crumb 

P1-LA-TC1 0.281 

P1-LA-TC1 640 115 115 17.9 

P1-LA-TC2 0.721 

P1-LA-TC2 2,490 598 598 24.0 

P1-LB-TC1 0.761 

P1-LB-TC1 2,490 788 787 31.6 

Mean 24.4 

Zn on Wipes 

Blank Ghost Wipe 4.06 

Wipe with Spike 800 763 759 94.8 

Blank Ghost Wipe 13.0 

Wipe with Spike 2,490 2,420 2,400 96.5 

Blank Ghost Wipe 23.6 

Wipe with Spike 2,490 2,430 2,410 96.7 

Mean 96.0 

Zn on Infill 

F4-L1-S1-A1 9,940 

F4-L1-S1-A1 800 8,960 -989 N/A 

F4-L1-D1-A1 4,880 

F4-L1-D1-A1 800 6,040 1,159 1,459 

F1-L3-S1-A1 7,930 

F1-L3-S1-A1 2,490 21,700 13,800 555 

F2-L2-D1-A1 10,300 

F2-L2-D1-A1 2,490 11,700 1,420 56.8 

Mean 251 

Zn on Crumb 

P1-LA-TC1 4,330 

P1-LA-TC1 800 5,270 940 117.5 

P1-LA-TC2 6,730 

P1-LA-TC2 2,490 13,100 6,380 256 

P1-LB-TC1 17,500 

P1-LB-TC1 2,490 14,000 -3,430 N/A 

Mean 186 

60
Table B-12. Total Extractable Recoveries for NIST SRM 2710 Spiked into Extraction 

Solution

Metal Batch 

SRM Certified 

Concentration 

(ug/g) 

Found 

Concentration 

(ug/g) 

Percent 

Recovery 

SRM 

Percent 

Leachable 

Recovery 

As 1 626 535 85.5 94 

2 626 502 80.3 94 

3 626 514 82.0 94 

4 626 492 78.5 94 

6 626 502 80.2 94 

8 626 498 79.5 94 

 Mean 81.0 

Cra 1 39 14.2 36.3 49 

2 39 16.3 41.8 49 

3 39 15.1 38.6 49 

4 39 10.1 26.0 49 

6 39 14.8 38.0 49 

8 39 13.8 35.4 49 

 Mean 37.5 

Pb 1 5,530 5,100 92.2 92 

2 5,530 4,740 85.7 92 

3 5,530 4,830 87.4 92 

4 5,530 4,830 87.3 92 

6 5,530 4,740 85.6 92 

8 5,530 4,630 83.7 92 

 Mean 87.0 

Zn 1 6,950 5,640 81.2 85 

2 6,950 5,040 72.5 85 

3 6,950 5,580 80.3 85 

4 6,950 5,300 76.2 85 

6 6,950 5,140 73.9 85 

8 6,950 5,200 74.8 85 

 Mean 76.5 

Al 1 64,400 18,300 28.3 28 

2 64,400 18,900 29.4 28 

3 64,400 18,400 28.5 28 

4 64,400 16,900 26.3 28 

6 64,400 17,600 27.3 28 

8 64,400 17,200 26.8 28 

 Mean 27.8 

Ba 1 707 329 46.6 51 

2 707 311 44.0 51 

3 707 267 37.8 51 

4 707 298 42.1 51 

6 707 304 43.0 51 

8 707 322 45.5 51 

 Mean 43.2 

Cd 1 21.8 17.0 78.1 92 

2 21.8 17.8 81.4 92 

3 21.8 20.2 92.7 92 

4 21.8 18.8 86.3 92 

6 21.8 17.9 82.2 92 

8 21.8 18.7 85.7 92 

 Mean 84.4 

61
Table B-12. Total Extractable Recoveries for NIST SRM 2710 Spiked into Extraction 

Solution (cont’d.)

Metal Batch 

SRM Certified 

Concentration 

(ug/g) 

Found 

Concentration 

(ug/g) 

Percent 

Recovery 

SRM 

Percent 

Leachable 

Recovery 

Cu 1 2,950 2,630 89.0 92 

2 2,950 2,490 84.3 92 

3 2,950 2,570 87.2 92 

4 2,950 2,500 84.6 92 

6 2,950 2,490 84.4 92 

8 2,950 2,510 85.0 92 

 Mean 85.8 

Fe 1 33,800 28,500 84.4 80 

2 33,800 24,100 71.2 80 

3 33,800 27,500 81.4 80 

4 33,800 25,400 75.0 80 

6 33,800 23,400 69.4 80 

8 33,800 23,000 67.9 80 

 Mean 74.9 

Mn 1 10,100 7,250 71.8 76 

2 10,100 6,890 68.2 76 

3 10,100 7,080 70.1 76 

4 10,100 6,610 65.4 76 

6 10,100 6,860 67.9 76 

8 10,100 6,880 68.2 76 

 Mean 68.6 

Ni 1 14.3 7.89 55.2 71 

2 14.3 9.89 69.2 71 

3 14.3 8.70 60.8 71 

4 14.3 5.50 38.5 71 

6 14.3 8.39 58.7 71 

8 14.3 7.96 55.6 71 

 Mean 56.3 a

Not certified for SRM.

62
Table B-13. Total Extractable Recoveries for NIST SRM 2710 Spiked onto Ghost Wipe 

Media 

Metal Type Batch 

SRM Certified 

Total Conc. 

(ug/g) 

Found 

Conc. 

(ug/sample) 

Blank Corrected 

Conc. 

(ug/g) 

Percent 

Recovery 

SRM Percent 

Leachable 

Recovery 

As SRM 1 626 507 507 80.90 94 

Blank 1 0.15 

As SRM 8 626 543 543 86.80 94 

Blank 8 0.13 

As SRM 9 626 496 496 79.2 94 

Blank 9 0.12 

 Mean 82.3 

Cra SRM 1 39 14.1 14.0 36.0 49 

Blank 1 0.09 

Cr SRM 8 39 17.7 11.4 29.3 49 

Blank 8 6.23 

Cr SRM 9 39 13.8 0.76 1.96 49 

Blank 9 13.0 

 Mean (n=3) 22.4 

 Mean (n=2) 32.6 

Pb 

SRM 1 5,530 4,950 4,950 89.5 92 

Blank 1 0.23 

SRM 8 5,530 5,040 5,040 91.1 92 

Blank 8 0.69 

SRM 9 5,530 4,500 4,500 81.4 92 

Blank 9 1.08 

 Mean 87.3 

Zn 

SRM 1 6,950 5,570 5,560 80.0 85 

Blank 1 5.11 

SRM 8 6,950 5,800 5,780 83.2 85 

Blank 8 12.9 

SRM 9 6,950 5,260 5,240 75.4 85 

Blank 9 23.7 

 Mean 79.5 

Al 

SRM 1 64,400 18,100 18,100 28.2 28 

Blank 1 0.37 

SRM 8 64,400 20,000 20,000 31.1 28 

Blank 8 2.14 

SRM 9 64,400 18,500 18,500 28.8 28 

Blank 9 7.71 

 Mean 29.3 

63
Table B-13. Total Extractable Recoveries for NIST SRM 2710 Spiked onto Ghost Wipe 

Media (cont’d.)

Metal Type Batch 

SRM Certified 

Total Conc. 

(ug/g) 

Found 

Conc. 

(ug/sample) 

Blank Corrected 

Conc. 

(ug/g) 

Percent 

Recovery 

SRM Percent 

Leachable 

Recovery 

Ba 

SRM 1 707 316 309 43.8 51 

Blank 1 6.84 

SRM 8 707 353 330 46.7 51 

Blank 8 22.7 

SRM 9 707 324 298 42.2 51 

Blank 9 25.5 

 Mean 44.2 

Cd 

SRM 1 21.8 16.4 16.4 75.0 92 

Blank 1 0.03 

SRM 8 21.8 18.2 18.1 83.2 92 

Blank 8 0.06 

SRM 9 21.8 17.9 17.9 81.9 92 

Blank 9 0.02 

 Mean 80.1 

Cu 

SRM 1 2,950 2,540 2,540 86.2 92 

Blank 1 0.02 

SRM 8 2,950 2,630 2,630 89.3 92 

Blank 8 0.25 

SRM 9 2,950 2,450 2,450 83.1 92 

Blank 9 0.44 

 Mean 86.2 

Fe 

SRM 1 33,800 27,500 27,500 81.4 80 

Blank 1 0.20 

SRM 8 33,800 29,100 29,100 86.0 80 

Blank 8 26.7 

SRM 9 33,800 23,800 23,700 70.2 80 

Blank 9 61.2 

 Mean 79.2 

Mn 

SRM 1 10,100 7,050 7,050 69.8 76 

Blank 1 0.03 

SRM 8 10,100 7,310 7,300 72.3 76 

Blank 8 10.3 

SRM 9 10,100 6,980 6,960 68.9 76 

Blank 9 23.3 

 Mean 70.3 

64
Table B-13. Total Extractable Recoveries for NIST SRM 2710 Spiked onto Ghost Wipe 

Media (cont’d.)

Metal Type Batch 

SRM Certified 

Total Conc. 

(ug/g) 

Found 

Conc. 

(ug/sample) 

Blank Corrected 

Conc. 

(ug/g) 

Percent 

Recovery 

SRM Percent 

Leachable 

Recovery 

Ni 

SRM 1 14.3 7.86 7.86 55.0 71 

Blank 1 0.00 

SRM 8 14.3 9.96 6.55 45.8 71 

Blank 8 3.42 

SRM 9 14.3 7.98 0.91 6.34 71 

Blank 9 7.08 

 Mean (n=3) 35.7 

 Mean (n=2) 50.4 a

Not certified for SRM.

65
Table B-14. Bottle Blank Data Used for Sample Correction and Reagent Blank Data 

Method 3050B (ng/mL) 

As Cr Pb Zn Al Ba Cd Cu Fe Mn Ni 

For In Vitro 2% HNO3

Bottle Blank ID 

TC 1-1 0.13 0.252 0.292 68.0 23.0 125 0.007 1.36 0.006 0.132 0.121 

TC 2-1 -0.016 0.059 0.114 10.4 3.46 11 -0.001 0.926 0.0 0.08 0.038 

TC 3-1 0.126 0.466 0.293 97.3 31.1 174 0.05 1.51 0.007 0.132 0.208 

TC 4-1 0.023 0.035 0.05 7.72 3.29 8.18 0.001 0.23 0.000 0.017 0.015 

TC 5-1 0.002 0.109 0.106 54.4 16.2 119 0.001 0.716 0.003 0.043 0.013 

TC 6-1 0.005 0.132 0.138 58.5 17.8 126 0.001 1.27 0.003 0.061 0.071 

TC 7-1 -0.022 0.027 0.087 9.60 2.81 11.4 0 0.372 0.001 0.023 0.026 

TC 8-1 -0.015 0.043 0.07 8.04 3.22 9.04 0 0.42 0.001 0.06 0.009 

TC 9-1 -0.031 0.041 0.071 8.63 1.70 7.31 0.002 0.261 0.000 0.012 0.074 

Mean (n=9) 0.057 0.129 0.136 35.8 11.4 65.6 0.008 0.784 0.003 0.062 0.064 

 Std. dev. 0.065 0.145 0.093 34.1 10.9 68.4 0.017 0.499 0.002 0.046 0.066 

 %RSD 114 112 68.3 95.2 95.6 104.3 222 63.6 98.0 73.1 102 

 MDL 0.367 0.201 0.082 0.409 1.99 0.668 0.219 0.335 0.006 0.178 0.268 

For EPA 3050B 5% HNO3

Bottle Blank ID 

TC 1-1 1.04 1.45 6.91 192 128 179 0.088 13.4 0.113 9.40 3.71 

TC 2-1 1.28 1.10 2.69 148 85.6 153 0.061 7.63 0.047 2.48 2.91 

TC 3-1 0.755 1.29 1.84 157 91.6 197 0.034 3.61 0.042 1.47 2.75 

TC 4-1 1.40 48.6 4.407 229 100 193 0.811 7.88 0.191 52.1 27.8 

TC 5-1 0.761 5.49 1.65 288 102 192 0.413 14.8 0.034 2.70 2.90 

TC 6-1 0.814 3.38 1.54 185 88.5 178 0.19 5.53 0.041 4.15 2.50 

TC 7-1 0.383 40.5 0.791 208 90.7 183 1.40 2.90 0.194 48.8 25.6 

TC 8-1 0.426 5.67 2.54 182 103 191 0.18 5.31 0.056 9.25 3.24 

TC 9-1 1.47 6.97 3.22 170 82.0 169 1.06 8.52 0.029 4.13 7.73 

Mean (n=9) 0.925 12.7 2.84 195 96.9 182 0.471 7.72 0.083 14.9 8.80 

 Std. dev. 0.398 18.3 1.86 42.4 13.9 14.0 0.500 4.08 0.067 20.4 10.3 

 %RSD 43.0 144 65.3 21.7 14.4 7.7 106 52.8 80.5 136 117 

 MDL 0.246 0.175 0.092 0.388 2.47 0.634 0.224 0.350 0.004 0.144 0.332 

For EPA 3050B Only Reagent Blanks 5% HNO3 Not Stored in Bottles 

Reagent Blank ID 

TC-4-13 Lost Lost Lost Lost Lost Lost Lost Lost Lost Lost Lost 

TC 5-13 0.936 5.20 1.56 301 92.6 173 0.472 11.3 0.044 2.69 12.3 

TC 6-13 0.971 1.02 7.04 166 95.9 168 0.035 6.31 0.109 11.2 2.93 

TC 7-13 0.074 8.15 1.39 156 78.6 187 0.314 1.37 0.038 9.01 5.63 

TC 9-13 0.382 271 2.76 285 60.8 167 2.74 3.44 1.043 460 152 

Mean (n=4) 0.591 71.2 3.19 227 82.0 174 0.890 5.60 0.308 121 43.2 

 Std. dev. 0.438 133 2.64 76.3 16.0 9.15 1.24 4.28 0.491 226 72.6 

 %RSD 74.1 187 82.8 33.6 19.5 5.3 140 76.6 159 187 168 

66
Table B-15. Laboratory and Field Ghost Wipe Blank Samples (not blank corrected; 

ng/mL) 

Blank 

Wipe ID As Cr Pb Zn Al Ba Cd Cu Fe Mn Ni 

Laboratory Blank Wipes 

For In Vitro 2% HNO3

TC 1-11 0.144 0.183 0.282 67.7 13.4 95.6 0.083 1.45 0.006 0.224 0.077 

TC 8-12 0.065 0.13 0.695 55.5 12.9 118 0.012 0.944 0.005 0.167 0.034 

TC 9-2 0.038 0.113 0.227 57.6 15.3 115 -0.001 0.902 0.003 0.086 0.064 

 Mean 0.082 0.142 0.401 60.3 13.8 110 0.048 1.099 0.005 0.159 0.058 

 std dev 0.055 0.037 0.256 6.53 1.29 12.4 0.050 0.306 0.002 0.069 0.022 

 %RSD 66.9 25.7 63.7 10.8 9.3 11.3 106 27.8 32.7 43.6 37.8 

MDL 0.367 0.201 0.082 0.409 1.99 0.668 0.219 0.335 0.006 0.178 0.268 

For EPA 3050B 5% HNO3

TC 1-11 2.45 2.34 9.20 232 133 261 0.252 9.58 0.114 9.41 2.16 

TC 8-12 1.61 67.9 8.10 207 97.5 177 0.777 6.61 0.313 112 37.4 

TC 9-2 2.47 136 13.7 297 124 179 1.24 11.6 0.63 246 78.2 

 Mean 2.17 68.9 10.3 245 118 205 0.75 9.27 0.35 123 39.3 

 std dev 0.49 67.0 2.95 46.4 18.0 47.8 0.49 2.53 0.26 119 38.0 

 %RSD 22.6 97.3 28.5 18.9 15.3 23.3 65.2 27.2 73.9 96.8 96.9 

MDL 0.25 0.17 0.09 0.39 2.47 0.63 0.22 0.35 0.00 0.14 0.33 

Field Blank Wipes 

For In Vitro 2% HNO3

TC 8-4 0.043 0.045 0.242 12.9 4.16 9.60 0.084 0.402 0.003 0.157 0.055 

TC 8-6 0.037 0.134 9.13 54.8 16.0 115 0.009 0.926 0.005 0.129 0.049 

TC 8-7 0.037 0.144 0.2 60.4 20.3 126 0.006 0.857 0.005 0.133 0.058 

 Mean 0.04 0.11 3.19 42.7 13.5 83.7 0.03 0.73 0.004 0.1400 0.054 

 std dev 0.00 0.05 5.14 26.0 8.37 64.4 0.04 0.28 0.001 0.015 0.005 

 %RSD 8.9 50.6 161 60.8 62.0 77.0 134 39.1 26.6 10.8 8.5 

Repeat Extract Analysis 

TC 8-6 0.034 0.146 9.27 55.0 15.8 115 0.009 0.926 0.005 0.153 0.048 

For EPA 3050B 5% HNO3

TC 8-4 1.72 9.68 9.75 246 109 189 1.40 7.75 0.15 19.6 5.960 

TC 8-6 1.17 7.37 4.72 209 127 186 0.18 6.30 0.14 14.2 5.04 

TC 8-7 1.35 665 7.84 371 138 173 3.01 7.12 2.63 1,170 358 

 Mean 1.42 227 7.44 276 125 183 1.53 7.06 0.97 401 123 

 std dev 0.28 379 2.54 85.1 14.9 8.79 1.42 0.73 1.43 666 203 

 %RSD 19.8 167 34.1 30.9 12.0 4.8 92.6 10.3 148 166 166 

67
Table B-16. Relative Percent Differences (RPD) for the Analysis of Duplicate Aliquots of 

Tire Crumb Infill from Synthetic Fields and Playground Tire Crumb Samples (μg/g) 

Sample Cr Pb Zn As 

Synthetic Field Infill Samples 

F4-L1-S1-A1 0.60 41.1 9,940 0.11 

F4-LI-S1-A2 0.25 10.7 5,320 0.08 

 RPD 84.0 118 60.6 33.3 

F4-L1-D1-A1 0.35 24.8 4,880 NRa

F4-L1-D1-A2 0.33 47.7 4,070 NR 

 RPD 6.0 63.2 18.0 

F4-L2-S1-A1 0.14 13.6 2,660 NR 

F4-L2-S1-A2 0.37 19.3 4,310 NR 

 RPD 88.9 34.4 47.6 

F4-L3-S1-A1 1.03 23.7 11,400 0.40 

F4-L3-S1-A2 0.98 20.0 8,190 0.28 

 RPD 5.0 16.7 33.1 35.9 

F1-L1-S1-A1 1.01 29.2 17,200 0.55 

F1-L1-S1-A2 0.95 18.5 19,200 0.18 

 RPD 6.2 44.9 10.9 102 

F2-L1-S1-A1 0.35 20.6 5,690 0.23 

F2-L1-S1-A2 0.92 26.5 9,930 0.24 

 RPD 90.2 25.3 54.4 3.9 

F2-L1-D1-A1 0.36 61.2 5,890 0.18 

F2-L1-D1-A2 0.24 36.0 3,120 0.22 

RPD 41.1 51.9 61.4 17.7 

F1-L3-S1-A1 0.54 20.6 7,930 0.29 

F1-L3-S1-A2 0.24 14.4 5,047 0.20 

RPD 76.0 35.2 44.4 38.1 

F1-L2-S1-A1 0.33 13.1 9,050 0.21 

F1-L2-S1-A2 0.54 34.7 8,541 0.25 

 RPD 47.2 90.2 5.8 21.1 

F2-L3-S1-A1 NR 21.6 10,700 0.22 

F2-L3-S1-A2 NR 29.1 10,300 0.25 

 RPD 29.6 3.5 11.4 

F2-L2-D1-A1 NR 36.4 10,300 0.44 

F2-L2-D1-A2 NR 27.5 10,700 0.24 

 RPD 27.9 3.19 58.2 

F2-L2-S1-A1 NR 33.0 10,500 0.28 

F2-L2-S1-A2 NR 30.6 10,100 0.13 

 RPD 7.7 3.6 74.7 

F2-L3-D1-A1 NR 43.7 10,200 0.20 

F2-L3-D1-A2 NR 22.4 12,300 0.26 

 RPD 64.7 18.7 29.1 

68
Table B-16. Relative Percent Differences (RPD) for the Analysis of Duplicate Aliquots of 

Tire Crumb Infill from Synthetic Fields and Playground Tire Crumb Samples (μg/g) 

(cont’d.)

Cr Pb Zn As 

Playground Tire Crumb Samples 

P1-LA-TC1 0.52 2.43 9,720 0.15 

P1-LA-TC2 1.66 46.3 11,100 0.96 

 RPD 104 180 13.7 146 

P2-TC1 1.61 7.75 18,000 0.25 

P2-TC2 2.97 3.42 12,100 0.28 

 RPD 59.5 77.5 39.4 10.1 

P1-LA-TC4 0.72 6.31 6,730 0.28 

P1-LA-TC5 0.76 4.64 8,250 0.59 

 RPD 5.8 30.4 20.3 72.1 

P1-LB-TC1 0.76 443 17,500 15.0 

P1-LB-TC2 0.26 0.99 6630 0.08 

 RPD 98.2 199 89.9 198 a

NR = Not reported. 

Table B-17. Recommended Control Limits for In Vitro Soil Quality Control Samples 

According to EPA Method 9200.1-86 

In Vitro QCs Frequency Control Limits Corrective Actions 

Reagent Blank Once per batch <25 μg/L Pb Make new fluid and rerun all 

analyses. 

Bottle Blank 5%a <50 μg/L Pb Check calibration and reanalyze 

as necessary. 

Blank Spike (10 mg/L) 5%a 85%-115% recovery Check calibration and/or source 

of contamination and reanalyze. 

Matrix Spike (10 mg/L) 10%a 75%-125% recovery Flag 

Duplicate Sample 10%a ±20% RPDb Flag 

Control Soil (NIST 2710) 5%a ± 10% RPDc Flag a

Minimum 1 in 20. 

b

RPD = relative percent difference. 

c

The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) RPD is based on 

certified values and mean RBA-Pb values of 75% for SRM 2710. 

69
70

Table B-18. Summary Control Limit Results for In Vitro Pb Bioaccessibility Quality 

Control Samples (Note: This method has not been validated for the types of samples 

collected in this scoping study.) 

In Vitro QC Parameters Analysis Frequency 

Control Limit 

Results Corrective Actions 

Reagent Blank 9 Reagent blank 

(batches 1-9) 

<5 μg/L Pb None 

Bottle Blank 9 Blank runs 

(batches 1-9) 

<5 μg/L Pb None 

Blank Spike (10 mg/L) 8 Blank spike runs 

(batches 1-8) 

90-105% 

recovery 

None 

Blank Ghost Wipe with Spike 

(10 mg/L) 

3 Blank wipe with 

spike runs 

(batches 1, 8, 9) 

87%-99% 

recovery None 

Blank Ghost Wipe with NIST SRM 

2710b

3 Wipes with 

SRM runs 

(batches 1, 8, 9) 

3%-6% RPDc

None 

NIST SRM 2710b 6 SRM runs 

(batches 1-4, 6, 8) 

0%-9% RPDc

None 

Infill Spike (10 mg/L) 4 Infill spike runs 

(batches 1-4) 

89%-104% 

recovery 

None 

Crumb Spike (10 mg/L) 3 Crumb spike runs 

(batches 1, 5, 9) 

87%-103% 

recovery 

None 

Duplicate Samples 

13 Pairs of infill 

samples and 4 pairs 

of crumb samples 

2.7%-124% for 

infill samples and 

4%-183% for 

crumb samples 

Noted in report 

Blank Ghost Wipe 

3 Blank ghost wipe 

runs 

(batches 1, 8, 9) 

<10 μg/wipe Pb 

None 

a

Minimum 1 in 20; matrix spikes for crumbs and infill only performed if enough material was available. b

The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) RPD is based on 

certified values and mean RBA-Pb values of 75% for SRM 2710. 

c

RPD = relative percent difference. 

Table B-19. Percent Recovery Results for In Vitro Blank Spikes 

Batch Number Sample ID 

Spiked 

Amount 

(mg/L) 

Recovered In Vitro 

Extractable Pb (mg/L) 

Percent Spike 

Recovery 

1 Blank Spike 10 9.0 89.7 

2 Blank Spike 10 9.9 99.5 

3 Blank Spike 10 10.2 102 

4 Blank Spike 10 10.2 102 

5 Blank Spike 10 10.2 102 

6 Blank Spike 10 10.5 105 

7 Blank Spike 10 10.0 100 

8 Blank Spike 10 10.1 101 

Mean 100 
Table B-20. Summary of Pb In Vitro Extractable Values for NIST SRM 2710 

SRM Certified Found 

Batch Number Concentration (ug/g) Concentration (ug/g) RPD 

1 75.0 81.7 8.9 

2 75.0 73.6 1.9 

3 75.0 74.1 1.2 

4 75.0 79.5 6.0 

6 75.0 81.3 8.3 

8 75.0 75.3 0.4 

Mean 75.0 77.6 4.5 

Table B-21. Summary of Pb In Vitro Extractable Values for SRM 2710 Spiked onto Ghost 

Wipe Media 

Type Batch 

SRM %IVBAa

(based on EPA SOP) 

Found 

(%IVBA) RPD 

SRM 1 75 79.7 6.22 

SRM 8 75 78.3 4.39 

SRM 9 75 77.6 3.45 

Mean 78.5 4.69 a

 In vitro bioaccessibility. 

71
Table B-22. Results for In Vitro Pb Solution Spikes onto Blank Ghost Wipes and Tire 

Crumb Samples 

Media and Spike 

Spiked 

Amount 

(mg/L) 

Net Spiked 

In Vitro 

Extractable 

(mg/L) 

Net Media 

In Vitro 

Extractable 

(mg/L) 

Media 

Corrected 

Spike 

Percent 

Recovery 

Pb on Wipes 

 Ghost Wipe with Spike 10 8.65 8.65 86.5 

 Blank Ghost Wipe 0.00 

 Ghost Wipe with Spike 10 9.93 9.93 99.3 

 Blank Ghost Wipe 0.01 

 Ghost Wipe with Spike 10 9.66 9.66 96.6 

 Blank Ghost Wipe 0.00 

Pb on Tire Crumb Infill 

 F4-L1-S1-A1 Spiked 10 8.86 8.86 88.6 

 F4-L1-S1-A1 Unspiked 0.01 

 F4-L1-DS1-A1 Spiked 10 10.0 10.0 100 

 F4-L1-DS1-A1 

Unspiked 0.01 

 F1-L3-S1-A1 Spiked 10 9.91 9.90 99.0 

 F1-L3-S1-A1 Unspiked 0.01 

 F2-L2-DS1-A1 Spiked 10 10.5 10.5 105 

 F2-L2-DS1-A1 

Unspiked 0.02 

Pb on Tire Crumb 

 P1-LA-TC1 Spiked 10 8.88 8.87 88.7 

 P1-LA-TC1 Unspiked 0.00 

 P1-LA-TC4 Spiked 10 10.3 10.3 103 

 P1-LA-TC4 Unspiked 0.00 

 P1-LB-TC1 Spiked 10 10.2 10.2 102 

 P1-LB-TC1 Unspiked 0.02 

72
73

Table B-23. In Vitro Pb Bioaccessibility Extraction Duplicates for Synthetic Turf Field Tire 

Crumb Infill

Sample Pb (%IVBA)a Sample Pb (%IVBA) 

F4-L1-S1-A1 1.7 F1-L3-S1-A1 4.2 

F4-L1-S1-A2 7.3 F1-L3-S1-A2 4.4 

RPD 124 RPD 4.6 

F4-L1-DS1-A1 3.9 F1-L2-S1-A1 5.0 

F4-L1-DS1-A2 2.4 F1-L2-S1-A2 1.6 

RPD 46.3 RPD 105 

F4-L2-DS1-A1 3.8 F2-L3-S1-A1 5.0 

F4-L2-DS1-A2 2.7 F2-L3-S1-A2 4.2 

RPD 34.7 RPD 17.9 

F4-L3-S1-A1 8.5 F2-L2-DS1-A1 5.0 

F4-L3-S1-A2 10.1 F2-L2-DS1-A2 4.5 

RPD 17.4 RPD 11.3 

F1-L1-S1-A1 9.6 F2-L2-S1-A1 7.6 

F1-L1-S1-A2 5.3 F2-L2-S1-A2 3.6 

RPD 57.2 RPD 72.3 

F2-L1-S1-A1 3.7 F2-L3-DS1-A1 3.1 

F2-L1-S1-A2 3.8 F2-L3-DS1-A2 5.5 

RPD 2.7 RPD 54.7 

F2-L1-DS1-A1 1.7 Maximum RPD 124 

F2-L1-DS1-A2 2.9 Minimum RPD 2.7 

RPD 52.9 Number 13 

a

%IVBA = percent in vitro bioaccessibility.

Table B-24. In Vitro Pb Bioaccessibility Extraction Duplicates for Playground Tire Crumb

Sample Pb (%IVBA)a Sample Pb (%IVBA) 

P1-LA-TC2 4.6 P1-LB-TC1 0.3 

P1-LA-TC3 0.3 P1-LB-TC2 6.4 

RPD 176 RPD 183 

P2-TC1 1.8 Maximum RPD 183 

P2-TC2 7.4 Minimum RPD 73.2 

RPD 122 Number 4 

P1-LA-TC4 2.4 

P1-LA-TC5 5.2 a

%IVBA = percent in vitro bioaccessibility.
Appendix C

Compilation of Environmental Sample Analysis Results

Table C-1. Results of Analysis for Grab VOC Air Samples 

Table C-2. Results of Analysis for Particle Mass on Integrated Air Samples 

Table C-3. Results of Analysis for Metals in Integrated Air Samples 

Table C-4. Results of SEM Analysis for Postulated Tire Crumb Particles on Integrated Air 

Samples 

Table C-5. Results of Analysis of Wet Wipe Samples for Total Extractable Metals 

Table C-6. Results of Analysis of Synthetic Turf Field Tire Crumb Infill for Total Extractable 

Metals 

Table C-7. Results of Analysis of Synthetic Turf Field Blades for Total Extractable Metals 

Table C-8. Results of Analysis of Playground Tire Crumb for Total Extractable Metals 

Table C-9. Results of Analysis of Synthetic Turf Field Infill Sample Analysis for Bioaccessible Pb 

Table C-10. Results of Analysis of Synthetic Turf Field Blade Sample Analysis for Bioaccessible 

Pb

Table C-11. Results of Analysis of Playground Tire Crumb Sample Analysis for Bioaccessible 

Pb 

74
Table C-1. Results of Analysis for Grab VOC Air Samples

VOC Sitea

ppbV 

Sampling Location at Siteb

μg/m3

Sampling Location at Siteb

A B C D A B C D 

F1D1 0.090 0.110 0.074 0.073 0.287 0.351 0.223 0.223 

F1D2 0.081 0.081 0.088 0.092 0.255 0.255 0.287 0.287 

F2 0.098 0.120 0.120 0.120 0.319 0.383 0.383 0.383 

F4 0.320 0.120 0.160 0.120 1.021 0.383 0.510 0.383 

Benzene 

P1 0.088 0.086 ―c 0.087 0.287 0.287 ― 0.287 

F1D1 0.140 0.98 0.140 0.150 0.527 3.688 0.527 0.564 

F1D2 0.120 0.110 0.110 0.120 0.452 0.414 0.414 0.452 

F2 0.180 0.180 0.190 0.190 0.677 0.677 0.715 0.715 

F4 0.510 0.190 0.150 0.190 1.919 0.715 0.564 0.715 

Toluene 

P1 0.140 0.430 ― 0.160 0.527 1.618 ― 0.602 

F1D1 NDd 0.170 ND 0.083 ND 0.737 ND 0.347 

F1D2 0.075 0.130 ND ND 0.303 0.564 ND ND 

F2 0.047 0.074 0.091 0.077 0.217 0.303 0.390 0.347 

F4 0.290 0.055 0.077 ND 1.257 0.217 0.347 ND 

m&p-Xylenes 

P1 ND 0.130 ― 0.050 ND 0.564 ― 0.217 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND 

o-Xylene 

ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 0.120 ND ND ND 0.520 ND ND ND 

P1 ND 0.045 ― ND ND 0.173 ― ND 

F1D1 ND 0.073 ND ND ND 0.303 ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 0.110 ND ND ND 0.477 ND ND ND 

Ethylbenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 0.082 ND ND ND 0.393 ND ND ND 

1,2,4-Trimethylbenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 0.082 ND ND ND 0.393 ND ND ND 

4-Ethyltoluene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND 0.320 0.092 0.063 ND 1.126 0.317 0.211 

F1D2 0.098 0.062 ND 0.078 0.352 0.211 ND 0.281 

F2 ND 0.049 0.110 0.045 ND 0.176 0.387 0.141 

F4 0.150 0.110 0.160 0.049 0.528 0.387 0.563 0.176 

Hexane 

P1 ND 0.300 ― ND ND 1.055 ― ND 

75
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV 

Sampling Location at Siteb

μg/m3

Sampling Location at Siteb

A B C D A B C D 

F1D1 ND 0.330 ND ND ND 1.134 ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Cyclohexane 

P1 ND 0.250 ― ND ND 0.859 ― ND 

F1D1 0.400 0.560 0.440 0.440 1.180 1.651 1.298 1.298 

F1D2 0.490 0.340 0.320 0.360 1.445 1.003 0.94 1.062 

F2 0.400 0.440 0.380 0.370 1.180 1.298 1.121 1.091 

F4 0.370 0.500 0.410 0.440 1.091 1.474 1.209 1.298 

Methyl Ethyl Ketone 

P1 0.340 0.480 ― 0.380 1.003 1.415 ― 1.121 

F1D1 0.088 0.110 0.180 ND 0.368 0.450 0.736 ND 

F1D2 0.120 0.110 ND ND 0.491 0.450 ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Methyl Isobutyl Ketone 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND 0.046 ND ND ND 0.204 ND ND 

F4 ND ND ND ND ND ND ND ND 

2-Hexanone 

P1 ND ND ― ND ND ND ― ND 

F1D1 0.090 0.092 0.084 0.097 0.566 0.579 0.528 0.610 

F1D2 0.097 0.100 0.093 0.098 0.610 0.629 0.585 0.616 

F2 0.088 0.100 0.092 0.084 0.554 0.629 0.579 0.528 

F4 0.088 0.089 0.086 0.098 0.554 0.560 0.541 0.616 

Carbon Tetrachloride 

P1 0.083 0.082 ― 0.094 0.522 0.516 ― 0.0.591 

F1D1 0.519 0.540 0.500 0.550 2.566 2.670 2.472 2.720 

F1D2 0.490 0.530 0.470 0.560 2.423 2.621 2.324 2.769 

F2 0.500 0.640 0.540 0.510 2.472 3.165 2.670 2.522 

F4 0.470 0.480 0.490 0.540 2.324 2.373 2.423 2.670 

Dichlorodifluoromethane 

P1 0.520 0.540 ― 0.540 2.571 2.670 ― 2.670 

F1D1 0.430 0.500 0.470 0.480 0.888 1.033 0.97 0.99 

F1D2 0.460 0.470 0.470 0.460 0.95 0.97 0.97 0.95 

F2 0.420 0.460 0.470 0.450 0.867 0.95 0.971 0.93 

F4 0.470 0.500 0.470 0.520 0.97 1.033 0.97 1.074 

Methylchloride 

P1 0.470 0.450 ― 0.450 0.97 0.93 ― 0.93 

F1D1 0.250 0.280 0.260 0.280 1.405 1.573 1.461 1.573 

F1D2 0.260 0.260 0.250 0.270 1.461 1.461 1.405 1.517 

F2 0.250 0.290 0.270 0.250 1.405 1.630 1.517 1.405 

F4 0.240 0.240 0.240 0.300 1.349 1.349 1.349 1.686 

Trichlorofluoromethane 

P1 0.260 0.260 ― 0.260 1.461 1.461 ― 1.461 

76
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV 

Sampling Location at Siteb

μg/m3

Sampling Location at Siteb

A B C D A B C D 

Trichlorotrifluoroethane F1D1 0.080 0.081 0.075 0.081 0.613 0.613 0.537 0.613 

F1D2 0.077 0.079 0.076 0.084 0.613 0.613 0.613 0.613 

F2 0.073 0.085 0.075 0.072 0.537 0.613 0.537 0.537 

F4 0.069 0.072 0.072 0.150 0.537 0.537 0.537 1.150 

P1 0.074 0.074 ― 0.074 0.537 0.537 ― 0.537 

Methylene Chloride F1D1 ND 0.074 0.062 0.062 ND 0.243 0.208 0.208 

F1D2 ND ND ND ND ND ND ND ND 

F2 0.058 0.069 0.062 0.059 0.208 0.243 0.208 0.208 

F4 0.055 0.055 0.065 0.061 0.208 0.174 0.208 0.208 

P1 0.071 0.110 ― 0.066 0.243 0.382 ― 0.243 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND 0.062 ND ND ND 0.293 ND ND 

F4 ND ND ND ND ND ND ND ND 

Chloroform 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,1,1-Trichloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,1,2,2-

Tetrachloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,1,2-Trichloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,1-Dichloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,1-Dichloroethylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,2,4-Trichlorobenzene 

P1 ND ND ― ND ND ND ― ND 

77
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV 

Sampling Location at Siteb

μg/m3

Sampling Location at Siteb

A B C D A B C D 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,2-Dibromoethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,2-Dichlorobenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,2-Dichloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,2-Dichloropropane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,3,5-Trimethylbenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,3-Butadiene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,3-Dichlorobenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

1,4-Dichlorobenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Acrylonitrile 

P1 ND ND ― ND ND ND ― ND 

78
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV 

Sampling Location at Siteb

μg/m3

Sampling Location at Siteb

A B C D A B C D 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Allyl Chloride 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Benzylchloride 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Bromodichloromethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Bromoform 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

cis-1,2-Dichloroethylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

cis-1,3-

Dichloropropylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Chlorobenzene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Chloroethane 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Dibromochloromethane 

P1 ND ND ― ND ND ND ― ND 

79
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV μg/m3

Sampling Location at Siteb Sampling Location at Siteb

A B C D A B C D 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND 

Dichlorotetrafluoroethane 

ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND 

Heptane 

ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND 

Hexachloro-1,3-

butadiene 

ND ND ND 

F4 ND ND ND ND ND ND ND ND 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Methylbromide 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Methyl-t-Butyl Ether 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Styrene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

trans-1,2-

Dichloroethylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

trans-1,3-

Dichloropropylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Tetrachloroethylene 

P1 ND ND ― ND ND ND ― ND 

80
Table C-1. Results of Analysis for Grab VOC Air Samples (cont’d.)

VOC Sitea

ppbV μg/m3

Sampling Location at Siteb Sampling Location at Siteb

A B C D A B C D 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Tetrahydrofuran 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Trichloroethylene 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Vinyl Bromide 

P1 ND ND ― ND ND ND ― ND 

F1D1 ND ND ND ND ND ND ND ND 

F1D2 ND ND ND ND ND ND ND ND 

F2 ND ND ND ND ND ND ND ND 

F4 ND ND ND ND ND ND ND ND 

Vinylchloride 

P1 ND ND ― ND ND ND ― ND a

Site identification: P = playground; F = synthetic turf field; D = day 1 or day 2. 

b

Sampling location: A, B, and C are “on field” or “on playground”; D is “upwind background.” c

Only two “on playground” sampling locations. 

d

ND = not detected.

81
Table C-2. Results of Analysis for Particle Mass on Integrated Air Samples (μg/m3

) 

Sampling Locationb 

Sitea A A Dup B B Dup C D Field Blank 

F1D1 27.5 ―c 28.6 29.0 27.4 29.5 0.6 

F1D2 29.6 ― 30.0 ― ― 29.5 0.4 

F4 33.4 31.0 30.9 ― 31.0 28.6 0.7 

P1 23.9 24.3 29.5 ― ― 14.2 0.2 

a

F = turf field, P = playground, D = day, Dup = duplicate sample. 

b

A, B, and C are “on field” or “on playground,” D is “upwind background.” 

c

Not collected. 

Table C-3. Results of Analysis for Metals in Integrated Air Samples (ng/m3)

a 

Site and Sampling 

Location at the Siteb Pb Cr Zn Ca Cl Cu Fe K Mn S Si Ti 

F1D1 location A ―c 2.3 6.6 449 14.1 8.9 230 134 6.1 4,004 1,291 20.4 

F1D1 location B ― ― 15.3 230 ― ― 201 91.7 ― 3,688 555 30.8 

F1D1 location B duplicate ― 2.8 13.6 370 ― ― 199 99.2 6.3 3,018 1,497 22.3 

F1D1 location C ― 3.6 10.6 349 ― ― 226 126 ― 3,946 796 24.7 

F1D1 location D ― 2.0 23.8 396 ― ― 240 128 7.5 3,667 1,405 25.2 

F1D1 field blank ― ― ― 34.5 12.2 ― ― 8.6 ― ― ― ―

F1D2 location A 7.7 4.3 17.0 834 21.0 10.3 364 164 9.3 3,680 1,248 29.4 

F1D2 location B ― 2.8 6.6 812 ― ― 364 158 10.6 3,784 858 27.9 

F1D2 location C NRd NR NR NR NR NR NR NR NR NR NR NR 

F1D2 location D 6.3 3.3 11.6 881 20.9 ― 356 178 8.4 3,933 1,548 31.9 

F1D2 field blank ― ― 9.5 ― ― ― ― ― 4.3 ― ― ―

F4 location A ― 3.4 36.0 487 25.5 21.3 803 302 18.5 3,044 2,646 58.7 

F4 location A duplicate ― 5.0 31.9 303 ― 20.0 559 191 13.0 1,516 2,116 44.0 

F4 location B ― ― 33.0 338 ― 13.4 663 228 13.4 2,845 1,912 58.2 

F4 location C ― ― 25.2 319 ― 12.2 573 238 10.9 2,952 1,942 51.4 

F4 location D ― 2.7 21.7 466 21.1 12.3 456 227 10.9 2,976 1,890 41.2 

F4 field blank ― ― ― 12.9 ― ― ― ― ― ― ― ―

P1 location A 5.1 3.6 90.7 317 118 11.8 672 196 8.6 664 2,784 57.6 

P1 location A duplicate ― 2.5 82.5 365 177 ― 748 240 13.6 882 2,435 63.7 

P1 location B ― 3.1 117 414 189 ― 987 312 15.0 903 3,455 92.3 

P1 location D ― ― 10.5 238 95.5 10.8 294 97.2 ― 751 516 21.4 

P1 field blank ― ― ― ― ― ― ― ― ― ― ― ― a

Values represent those less than three times the measurement uncertainty limit following field blank corrections. b

F = turf field, P = playground, D = day, Dup = duplicate sample. bDesignations A, B, and C refer to “on field” or “on playground” 

locations; D locations represent background sites. 

c

― Represents values less than three times the measurement uncertainty limit. d

NR = sample filter inverted during collection; analysis results not reported. 

82
Table C-4. Results of SEM Analysis for Postulated Tire Crumb Particles on Integrated Air 

Samplesa

Sample IDb

Number of 

Postulated 

Tire Crumb 

Particlesc

Mass of 

Postulated 

Tire Crumb 

Particlesc

(pg) 

Scaled 

Mass of 

Postulated 

Tire Crumb 

Particlesd (μg) 

Estimated 

Concentration of 

Postulated Tire 

Crumb Particles 

(μg/m3) 

F1D1 location A 5 6 0.01 0.001 

F1D1 location A duplicate 15 80 0.02 0.004 

F1D1 location A dup. Repeat 5 65 0.03 0.007 

F1D1 location B 18 90 0.08 0.019 

F1D1 location D 7 16 0.01 0.003 

 

F4 location A 0 0 0.00 0.000 

F4 location A duplicate 4 19 0.01 0.003 

F4 location B 6 47 0.03 0.007 

F4 location D 6 15 0.01 0.002 

P1 location A 63e 3,330 3.9 0.77 

P1 location B 58f 2,530 2.1 0.42 

P1 location D 5 40 0.03 0.005 a

Given the lack of unique composition and morphology for tire crumb particles from the collected materials, the 

estimates in this table have considerable uncertainty. 

b

F= synthetic turf field; P = playground; A and B are “on field” or “on playground;” D = “upwind background.” c

Raw numbers, not normalized to the same analyzed area. (CCSEM areas analyzed ranged from 0.6 mm2 to 3.6 

mm2

). d

Estimated tire crumb mass scaled to total exposed filter area of 6.7 cm2. e

Mass median diameter ~2.6 μm. 

f

Mass median diameter ~2.2 μm. 

83
Table C-5. Results of Analysis of Wet Wipe Samples for Total Extractable Metals (μg/ft2

; 

based on total extractable amounts from consecutive in vitro and Method 3050B 

extractions) 

Site and Sample 

Locationa Pb Cr Zn Al As Ba Cd Cu Fe Mn Ni 

F1D1 Loc. A, S 0.500 0.112 35.9 19.5 0.051 NR <MDLb 2.97 77.1 0.738 0.241 

F1D1 Loc. A, DS 0.489 0.178 43.3 26.3 0.055 0.351 <MDL 3.59 104 0.923 0.123 

F1D1 Loc. B, Sc 1.46 0.413 34.4 27.0 0.062 0.083 <MDL 2.77 91.0 1.09 0.221 

F1D1 Loc. B, DSc 1.91 0.517 38.4 22.5 0.102 NR 0.022 2.61 81.3 1.13 0.184 

F1D1 Loc. C, S 0.347 0.214 30.9 18.6 0.033 5.05 <MDL 2.06 74.2 0.690 0.149 

F1D1 Loc. C, DS 0.323 0.077 21.3 17.3 0.028 NR <MDL 1.69 71.5 0.598 0.177 

F1D2 Loc. A, S 0.370 0.096 26.4 17.6 0.045 NR <MDL 2.05 68.6 0.741 0.065 

F1D2 Loc. A, DS 0.407 0.197 34.9 21.1 0.039 NR <MDL 2.68 87.7 0.882 0.122 

F1D2 Loc. B, Sc 0.731 0.278 37.4 30.4 0.050 0.387 0.008 2.79 100 1.02 0.165 

F1D2 Loc. B, DSc 1.39 NRd 29.1 28.9 0.058 0.564 NR 2.20 87.3 0.356 NR 

F1D2 Loc. C, S 0.688 NR 40.6 30.0 0.049 0.280 NR 2.69 91.5 NR NR 

F1D2 Loc. C, DS 0.346 NR 25.7 18.2 0.045 NR NR 1.92 75.6 NR NR 

F2 Loc. A, S 0.456 NR 19.3 52.1 0.049 0.125 NR 0.677 116 NR NR 

F2 Loc. B, S 0.280 NR 13.0 28.0 0.026 7.31 <MDL 0.549 78.9 NR NR 

F2 Loc. C, S 0.289 NR 9.24 33.3 0.024 1.16 NR 0.488 74.8 NR NR 

F4 Loc. A, S 0.177 NR 5.28 42.7 0.022 0.085 NR 0.326 61.3 NR NR 

F4 Loc. A, DS 0.139 NR 4.25 36.1 0.018 0.384 <MDL 0.280 49.5 NR NR 

F5 Loc. B, S 0.129 NR 6.29 19.6 0.020 6.10 NR 0.203 28.5 NR NR 

F6 Loc. C, S 0.184 0.245 13.6 16.4 0.027 5.94 0.006 0.305 33.7 0.520 NR 

F1D1 Field Blank 0.181 0.096 1.79 0.17 0.034 NR 0.033 0.057 2.28 0.253 0.067 

F4 Field Blank 0.541 0.046 3.17 1.25 0.021 5.60 <MDL 0.051 2.15 0.124 0.046 

F4 Field Blank 0.135 16.0 7.36 1.76 0.025 5.84 0.068 0.067 62.1 27.1 8.54 

a

F = synthetic turf field; D = day 1 or day 2; Loc. = “on field” sampling location at site, S = sample collected at the 

location, DS = duplicate sample collected immediately adjacent to the sample. b

<MDL = extract concentration less than the method detection limit in both in vitro and Method 3050B analyses. c

Location B wipe samples from red synthetic turf in end zone. 

d

NR = not reported; analytical result <0 after blank correction. 

84
Table C-6. Results of Analysis of Synthetic Turf Field Tire Crumb Infill for Total 

Extractable Metals (μg/g; based on total extractable amounts from consecutive in vitro 

and Method 3050B extractions) 

Site, Sampling 

Location, Sample, 

and Aliquota Pb Cr Zn Al As Ba Cd Cu Fe Mn Ni 

F1 L1, S1, A1 29.2 1.01 17,200 218 0.55 68.4 0.87 23.7 416 4.54 8.95 

F1 L1, S1, A2 18.5 0.95 19,200 233 0.18 7.01 0.97 24.0 535 13.6 7.55 

F1 L2, S1, A1 13.1 0.33 9,050 168 0.21 NR 0.79 8.73 196 3.16 2.50 

F1 L2, S1, A2 34.7 0.54 8,540 167 0.25 NR 0.81 6.54 168 3.25 2.04 

F1 L3, S1, A1 20.6 0.54 7,930 170 0.29 NR 1.05 7.96 241 3.94 3.52 

F1 L3, S1, A2 14.4 0.24 5,050 171 0.20 NR 0.69 2.64 150 3.48 2.44 

F2 L1, S1, A1 20.6 0.35 5,690 345 0.23 NR 0.35 3.46 215 4.66 0.78 

F2 L1, S1, A2 26.5 0.92 9,930 533 0.24 56.0 0.60 10.7 476 3.85 1.95 

F2 L1, DS1, A1 61.2 0.36 5,890 473 0.18 37.5 0.55 2.63 209 3.71 0.82 

F2 L1, DS1, A2 36.0 0.24 3,120 376 0.22 5.67 0.68 1.18 134 3.36 0.70 

F2 L2, S1, A1 33.0 NRb 10,500 347 0.28 35.8 0.46 13.6 228 NR NR 

F2 L2, S1, A2 30.6 NR 10,100 330 0.13 18.3 0.37 15.8 210 NR NR 

F2 L2, DS1, A1 36.4 NR 10,300 289 0.44 26.4 1.05 16.8 429 NR NR 

F2 L2, DS1, A2 27.5 NR 10,700 309 0.24 12.3 0.47 14.1 227 NR NR 

F2 L3, S1, A1 21.6 NR 10,700 368 0.22 44.7 0.47 14.4 247 NR NR 

F2 L3, S1, A2 29.1 NR 10,300 386 0.25 43.5 0.45 14.2 283 NR NR 

F2 L3, DS1, A1 43.7 NR 10,200 426 0.20 98.5 0.52 14.6 239 NR NR 

F2 L3, DS1, A2 22.4 NR 12,300 373 0.26 76.6 0.68 17.2 269 NR NR 

F4 L1, S1, A1 41.1 0.60 9,940 307 0.11 21.0 0.29 7.32 160 2.27 0.94 

F4 L1, S1, A2 10.7 0.25 5,320 290 0.08 15.7 0.30 1.54 125 1.59 0.37 

F4 L1, DS1, A1 24.8 0.35 4,880 328 -0.03 71.1 <MDL 2.47 232 3.92 <MDL 

F4 L1, DS1, A2 47.7 0.33 4,070 268 <MDL 39.2 <MDL 2.13 154 3.82 <MDL 

F5 L1, S1, A1 13.6 <MDLc 2,660 201 <MDL 18.7 <MDL 1.01 104 4.01 <MDL 

F5 L1, S1, A2 19.3 <MDL 4,310 269 <MDL 32.1 <MDL 2.57 111 2.79 <MDL 

F6 L1, S1, A1 23.7 1.03 11,400 456 0.40 42.6 1.55 13.6 539 7.91 2.17 

F6 L1, S1, A2 20.0 0.98 8,190 555 0.28 33.9 1.36 8.5 745 8.73 1.41 

a

F = synthetic turf field; L = site sampling location; S = sample collected at the location; DS = duplicate sample 

collected at the location; A = aliquot of tire crumb infill from sample (~1 g each). b

NR = not reported; analytical result <0 after blank correction. c

<MDL = extract concentration less than the method detection limit in both in vitro and Method 3050B analyses. 

85
Table C-7. Results of Analysis of Synthetic Turf Blades for Total Extractable Metals (μg/g; 

based on total extractable amounts from consecutive in vitro and Method 3050B 

extractions)

Site and 

Blade Colora Pb Cr Zn Al As Ba Cd Cu Fe Mn Ni 

F1 Red 389 73.1 351 1,090 0.40 141 0.16 5.83 738 7.70 1.96 

F1 Green 3.84 9.71 316 2,090 0.47 88 0.07 44.8 2,060 9.41 3.22 

F1 White 4.28 0.99 688 1,320 0.60 114 NRb 7.42 721 6.83 3.98 

F1 Black 2.76 1.91 729 1,290 0.29 111 NR 5.91 787 6.02 1.00 

F3 Red 2.40 1.20 199 947 0.22 1,950 NR 3.19 449 8.35 0.10 

F3 White 1.97 0.08 255 336 NR 38 NR 1.54 138 3.36 1.66 

F4 Green, white, 

yellow mix 2.08 3.72 206 2,120 0.25 50 NR 74.1 4,950 12.07 2.94 

F5 Green, white, 

yellow mix c 701 177 131 1,620 0.12 40 <MDLd 68.3 3,300 6.05 2.43 

F6 Green, white, 

yellow mix 77.1 18.9 175 1,150 0.05 303 NR 34.9 3,230 4.94 14.3 

a

F = synthetic turf fields. 

b

NR = not reported; analytical result <0 after blank correction. c

Blade samples collected from a field with an apparently patched area. Also, the Method 3050B extract for this 

sample spilled during processing. 

d

<MDL = extract concentration less than the method detection limit in both in-vitro and Method 3050B analyses. 

Table C-8. Results of Analysis of Playground Tire Crumb for Total Extractable Metals 

(μg/g; based on total extractable amounts from consecutive in vitro and Method 3050B 

extractions) 

Site, Sampling 

Location, and Tire 

Crumb Piecea

 Pb Cr Zn Al As Ba Cd Cu Fe Mn Ni 

P1 Loc. A, TC 1 0.99 0.28 4,330 96.4 0.04 5.70 0.09 0.05 37.2 0.47 0.24 

P1 Loc. A, TC 2 2.43 0.52 9,717 92.3 0.15 0.72 0.34 1.02 82.3 1.29 0.25 

P1 Loc. A, TC 3 46.3 1.66 11,100 372 0.96 18.9 6.14 1.82 384 4.58 1.60 

P1 Loc. A, TC 4 6.31 0.72 6,730 138 0.28 3.75 0.84 2.83 154 2.81 0.62 

P1 Loc. A, TC 5 4.64 0.76 8,250 799 0.59 3.46 0.11 1.66 274 1.86 2.09 

P1 Loc. B, TC 1 443 0.76 17,500 350 15.0 13.3 10.5 3.74 320 8.83 2.48 

P1 Loc. B, TC 2 0.99 0.26 6,630 44.3 0.08 1.89 0.05 1.26 57.4 2.24 0.79 

P2 TC 1 7.75 1.61 18,000 126 0.25 8.46 0.21 2.74 1,900 7.76 1.69 

P2 TC 2 3.42 2.97 12,100 170 0.28 11.0 0.67 4.98 6,180 4.27 1.11 

a

P = playground; Loc. = sampling location; TC = different pieces of tire crumb from two sampling locations at site P1 

were analyzed; two pieces of tire crumb from site P2 were analyzed. 

86
Table C-9. Results of Analysis of Synthetic Turf Field Infill Sample Analysis for 

Bioaccessible Pb 

Site, Sampling Location, Sample, 

and Aliquota

Total Extractable Pb 

(μg/g) 

Pb In Vitro 

Bioaccessibility Value (%)b

F1 L1, S1, A1 29.2 9.6 

F1 L1, S1, A2 18.5 5.3 

F1 L2, S1, A1 13.1 5.0 

F1 L2, S1, A2 34.7 1.6 

F1 L3, S1, A1 20.6 4.2 

F1 L3, S1, A2 14.4 4.4 

F2 L1, S1, A1 20.6 3.7 

F2 L1, S1, A2 26.5 3.8 

F2 L1, DS1, A1 61.2 1.7 

F2 L1, DS1, A2 36.0 2.9 

F2 L2, S1, A1 33.0 7.6 

F2 L2, S1, A2 30.6 3.6 

F2 L2, DS1, A1 36.4 5.0 

F2 L2, DS1, A2 27.5 4.5 

F2 L3, S1, A1 21.6 5.0 

F2 L3, S1, A2 29.1 4.2 

F2 L3, DS1, A1 43.7 3.1 

F2 L3, DS1, A2 22.4 5.5 

F4 L1, S1, A1 41.1 1.7 

F4 L1, S1, A2 10.7 7.3 

F4 L1, DS1, A1 24.8 3.9 

F4 L1, DS1, A2 47.7 2.4 

F5 L1, S1, A1 13.6 3.8 

F5 L1, S1, A2 19.3 2.7 

F6 L1, S1, A1 23.7 8.5 

F6 L1, S1, A2 20.0 10.1 

Mean 4.7 ± 2.3 

Minimum 1.6 

Maximum 10.1 a

L = sampling location at site, S = sample collected at the location, DS = duplicate sample collected at the location, 

A = aliquot of tire crumb infill from sample (~1 g each). 

b

The in vitro bioaccessibility values were determined by dividing the amount of Pb extracted in the in vitro extraction 

by the total extractable amount of Pb. 

87
Table C-10. Results of Analysis of Synthetic Turf Field Blade Sample Analysis for 

Bioaccessible Pb 

Sitea and Blade Color 

Total Extractable Pb 

(μg/g) 

Pb In Vitro 

Bioaccessibility Value (%)a

F1 Red 389 2.3 

F1 Green 3.84 40.9 

F1 White 4.28 43.0 

F1 Black 2.76 86.8 

F3 Red 2.40 40.3 

F3 White 1.97 38.7 

F4 Green, white, yellow mix 2.08 54.4 

F5 Green, white, yellow mix 701 0.2 

F6 Green, white, yellow mix 77.1 1.0 

Mean 34.2 ± 28.8 

Minimum 0.2 

Maximum 86.8 a F = field site. 

b

The in vitro bioaccessibility values were determined by dividing the amount of Pb extracted in the in vitro extraction 

by the total extractable amount of Pb. 

Table C-11. Results of Analysis of Playground Tire Crumb Sample Analysis for 

Bioaccessible Pb 

Site, Sampling Location, and 

Tire Crumb Piecea

Total Extractable Pb 

(μg/g) 

Pb In Vitro 

Bioaccessibility Value (%)b

P1 Loc. A, TC1 0.99 10.7 

P1 Loc. A, TC2 2.43 4.6 

P1 Loc. A, TC3 46.3 0.3 

P1 Loc. A, TC4 6.31 2.4 

P1 Loc. A, TC5 4.64 5.2 

P1 Loc. B, TC1 443 0.3 

P1 Loc. B, TC2 0.99 6.4 

P2 TC1 7.75 1.8 

P2 TC2 3.42 7.4 

Mean 4.3 ± 3.5

Minimum 0.3 

Maximum 10.7 a

L = sampling location at site, TC = tire crumb piece analyzed from the location. 

b

The in vitro bioaccessibility values were determined by dividing the amount of Pb extracted in the in vitro extraction 

by the total extractable amount of Pb.

88
Appendix D

Air PM10 SEM Analysis Report 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL EXPOSURE RESEARCH LABORATORY 

Human Exposure and Atmospheric Sciences Division 

Research Triangle Park, NC 27711 

SEM Analysis of Tire Crumb Samples 

Bob Willis 

February 23, 2009 

Sample Collection 

PM10 samples were collected by the EPA on playgrounds and turf fields that used tire crumb 

(TC) for a base. Samples were collected at two synthetic turf fields in EPA Regions 4 and 5 and 

at one playground in EPA Region 3. Samples were collected on 37mm polycarbonate filters 

(0.4 μm pore) using a Harvard Impactor employing a 10 μm inlet. Samples were collected for 

approximately 400 min at a flow rate of 10 lpm, giving a total sampled volume of about 4 m3

. 

Duplicate samples were collected to assess precision and background samples were collected for 

comparison from nearby playgrounds/turf fields that did not use tire crumbs. 

In addition to ambient samples collected on the playgrounds and turf fields, TC particles 

collected from the field’s crumb base were provided from each of the three sites to provide 

“source profiles” to assist in identifying TC-related particles in the ambient samples. 

Sample Preparation 

Source samples: Individual “crumbs” from the bulk sample, typically a couple of mm in size, 

were deposited “as is” on a sticky carbon tab. Source particles closer in size to the ambient 

sample were generated by shaving pieces from larger crumbs using a stainless steel razor blade. 

Source samples were coated with ~200 Å film of conductive carbon to minimize charge build-up 

on the sample during SEM analysis. 

Air PM10 samples: 5 mm x 5mm sections were cut from each polycarbonate filter using a 

stainless steel scalpel. Each section was affixed to a standard 12-mm aluminum specimen stub 

using a double-sided sticky carbon tab. The samples were then coated with ~200 Å of carbon to 

minimize sample charging by the electron beam during SEM analysis. 

Sample Analysis 

Samples were analyzed by Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray 

Spectrometry (EDS) using the Personal SEM (R.J. Lee Instruments Ltd.) in the NERL Electron 

Microscopy Laboratory. Manual SEM/EDX analysis was first conducted on the bulk TC source 

samples provided. Chemistry and morphological features characteristic of the TC material were 

89
identified to help identify TC particles in the ambient samples. Ambient samples were analyzed 

by computer-controlled SEM (CCSEM/EDX). Instrument parameters for the CCSEM analyses 

included: 20 kV accelerating voltage, Backscattered electron (BSE) imaging mode, 16 mm 

working distance, zero tilt. The BSE mode yields a more uniform background than the secondary 

electron (SE) mode, necessary for computer-controlled SEM, but at the expense of some loss in 

sensitivity for small carbonaceous particles: carbonaceous TC particles about 1 micron or smaller 

can be difficult to distinguish from the polycarbonate filter substrate in CCSEM analyses. Thus, 

small carbonaceous particles may be under-reported in these analyses. 

The CCSEM analysis was set up to analyze particles with average diameters between 1 and 

20 μm. Few particles >10 μm, however, were observed in any sample. All particles within this 

size range were automatically sized and analyzed by EDS for chemistry. Based on the analyses 

of the tire crumb source samples, Sulfur, Zinc, and Carbon were identified as possible indicators 

of TC material. Rules were developed to optimize the search for TC-like particles by extending 

the X-ray analysis time (10 s) and saving low-resolution images for all particles containing S, 

Zn, or C. Images and spectra for these particle types were manually reviewed off-line and 

particles were subjectively judged o be either TC-like, or not TC material based on the particle 

morphology and chemistry. 

Only a small fraction of the 6.7 cm2

 deposit area of each ambient filter was analyzed by CCSEM, 

typically about 1 mm2

, to complete each analysis in a reasonable time. 

Following CCSEM analyses, the EDX spectra and images of the particles of interest were 

manually reviewed, particles were relocated in the SEM for further examination and suspected 

TC particles were flagged. 

Results 

Source samples: Figures 1-10 are SEM photos of tire crumb material used at the three sampling 

sites. The TC particles examined did not show a single, unique, easily identifiable x-ray 

spectrum or particle morphology. Many of the tire crumbs displayed an “exterior” and an 

“interior” surface (Figs. 1, 2, 3a, 4a). The exterior surface often had a rough, fractured surface 

decorated with super-micron crustal-like aluminosilicate particles, quartz, and Fe-rich particles. 

(Figs. 3b, 4a). Freshly exposed interior surfaces tend to have a smooth surface embedded with 

many sub-micron Zn-rich inclusions (Figs. 4b, 5-7). It is postulated that some of the sub-micron 

Zn-rich particles observed in the ambient samples (e.g., Figs. 15, 21, 24, 37, 39, 43, 45, 46) may 

have been liberated from the TC matrix as part of the mechanical wear process. Carbon and 

sulfur were consistently present in TC particles; zinc was usually, but not always observed in TC 

particles (Fig. 8), and often was found at a trace level (Fig. 9). TC particles varied considerably 

in morphology such that it is difficult to identify a typical or characteristic TC morphology. 

Infrequently, TC source sample particles had the appearance of a bundle of fibers (Fig. 10). 

It is questionable whether the morphologies observed in these very large source particles are of 

any relevance in identifying PM10 TC particles collected on the air filters. 

Air PM10 samples: Particle loadings on ambient samples were excellent for CCSEM, with 

relatively few instances of particles touching or overlapping. Representative field images are 

shown in Figs. 11 and 12 (samples from Site F1 Location B and Site F1 Location D, 

90
respectively). Figures 13-46 show images and X-ray spectra of a subset of postulated TC 

particles found in samples from the three sites. 

Table 1 below summarizes the results of the CCSEM analyses of 11 samples. The third column 

of Table 1 (#TC) shows the number of TC-like particles identified in each sample after manual 

review of the CCSEM data. The area analyzed by CCSEM differed somewhat for each sample, 

and the number of TC-like particles reported is not normalized to the area, so these numbers 

cannot be strictly compared between samples. The TC mass associated with each particle is 

estimated by assuming the particle to be a prolate sphere, calculating the volume from the 

projected area of the particle, and assuming a density for each particle. (For particles which are 

primarily carbonaceous, a density of 1.5 was assumed. For particles which are mostly 

noncarbonaceous, the density is the average weighted density calculated from the EDS spectrum 

where the density of each metal detected in the particle (excluding carbon) is weighted by its 

fraction of X-ray counts in the EDS spectrum). The Scaled TC Mass is the estimated TC mass on 

the entire filter, assuming that the area analyzed is representative of the filter as a whole, and that 

the exposed filter area is 6.7 cm2

. The estimated tire crumb concentration in each sample 

Table 1. Concentration of TC-like particles in ambient samples. 

 Mass Scaled TC TC 

Sample ID Run # # TCa TCa pg Massb μg μg/m3

F1D1 Location B 10C 18 90 0.08 0.019 

F1D1 Location A 21D 5 6 0.01 0.001 

F1D1 Location A Duplicate 9D 15 80 0.02 0.004 

F1D1 Location A Dup 

Repeat 21B 5 65 0.03 0.007 

F1D1 Location D 

(background) 21C 7 16 0.01 0.003 

 

F4 Location B 28C 6 47 0.03 0.007 

F4 Location A 28D 0 0 0.00 0.000 

F4 Location A Duplicate 28B 4 19 0.01 0.003 

F4 Location D 

(background) 28A 6 15 0.01 0.002 

P1 Location A 22A 63c 3330 3.9 0.77 

P1 Location B 16E 58d 2530 2.1 0.42 

P1 Location D 

(background) 16D 5 40 0.03 0.005 a

These are raw numbers, not normalized to the same analyzed area. (CCSEM areas 

analyzed ranged from 0.6 mm2

 to 3.6 mm2). 

b

Estimated TC mass scaled to total exposed filter area of 6.7 cm2. c

Mass median diameter ~2.6 μm. 

d

Mass median diameter ~2.2 μm. 

91
assumes a sample volume of 4 m3

. Samples highlighted in yellow (D sites) were collected at 

playgrounds or turf fields which did not use TC material, but which were located near the A and 

B sites. 

There is no independent means or SEM calibration standard to check the accuracy of the SEM 

analyses reported in Table 1. These are crude estimates whose uncertainty could be at least a 

factor of ±5. (See caveats in Discussion section). 

Discussion 

Even though the numbers in Table 1 have large uncertainties in absolute terms, the two P1 

samples (Locations A and B) collected at a playground using TC material, clearly stand out from 

all other samples. These two samples showed much higher number and mass concentrations of 

TC-like particles than samples collected at the background sampling location (Location D) and at 

all F1 and F4 sampling locations. The TC-like mass concentrations at the two P1 sampling 

locations were estimated to be 90x and 160x higher than the background sample, with estimated 

concentrations of about 0.53 and 0.96 μg/m3

, respectively in the PM10 size fraction. In eight of 

the remaining ten samples, there were ≤ 7 TC-like particles, too few to support any conclusions 

regarding differences between the “on field” and background sampling locations. Although the 

data suggest possible enrichment of TC-like particles in F1 samples at Locations B and A 

(duplicate), an earlier analysis of the collocated sample from Location A did not show a 

significant enrichment in TC mass concentration compared to the background sample. The repeat 

analyses of the Location A duplicate sample provides a rough assessment of the overall analysis 

precision including the CCSEM analysis and the subjective, manual data interpretation. This 

precision is about 50% and is attributed to the small number of candidate particles coupled with 

the subjective nature of the particle classification. The estimated mass median diameters of the 

TC-like particles in samples in the P1 Location A and Location B samples were 2.6 μm (63 

particles) and 2.2 μm (58 particles), respectively. 

Concern has been expressed about the potential for inhalation exposure to fibers from TC 

material. Very few fibers were observed in any of these samples and none that could be 

attributed to TC. 

A number of factors may contribute to the observed enrichment in TC-like particles at the P1 site 

and the lack of enrichment at the F1 and F4 sites: (1) The P1 site was a playground (as opposed 

to a turf field); (2) the P1 site may have had more and/or more vigorous activity during the 

sampling period than the other sites; (3) the P1 sampler may have been located in an area of 

unusually high ambient TC concentrations; (4) TC materials vary in composition and mechanical 

wear properties. In particular, Zn concentrations in tires can vary nearly a factor of 10: the TC 

material used in the P1 site may have had elevated Zn compared to the TC material used at the 

F1 and F4 sites. Since the range of Zn concentrations in tires approximates the EDS detection 

limit for Zn, any increase in the Zn concentration of the TC material would have a major effect 

on the number of TC-like particles identified by CCSEM. (ICP analyses of the bulk TC samples 

should answer this question). 

Caveats: The ability to quantify the TC concentration in these samples by SEM/EDS hinges on 

the TC particles having distinct and unique composition and/or morphology which would enable 

92
the analyst to identify TC particles with a high degree of confidence. This does not seem to be 

the case for TC particles, as seen in the variety of morphologies and compositions in Figs. 1-10. 

The identification of the TC particles in Table 1 was a subjective judgment and large 

uncertainties should be assumed in the estimated TC contributions in Table 1. Reasonable 

arguments could be made that the TC concentration estimates in Table 1 are either 

underestimates or overestimates. For example, the chemical markers used to identify TC 

particles (C, S, and Zn) are not unique to tire crumbs and can be found in particles from common 

non-TC sources, potentially resulting in an overestimate. On the other hand, Zn, being the most 

critical tracer for TC, is poorly detected by EDS. It is possible that many Zn-bearing TC particles 

are undetected in the CCSEM analysis because the Zn concentration is just below the minimum 

detectable level, thus resulting in an underestimate of the TC concentration. 

As seen in Fig. 11, most particles 1 μm and smaller are sulfate particles whose X-ray spectra 

show both C and S (C is contributed by the polycarbonate substrate). Distinguishing TC particles 

from these sulfate particles based on chemistry alone is difficult, if not impossible. And, as 

discussed above, identifying TC particles by morphology for particles this small is probably not 

feasible. However, many, if not most, sulfate particles are damaged by the focused electron beam 

which leaves a visible hole in the particle. TC particles are not expected to exhibit similar beam 

sensitivity, so this may provide a means of distinguishing TC particles from most sulfate 

particles. Isolated Zn-S particles (e.g., Figs. 19 and 20) were observed in most samples and 

attributed to TC, even though there may be industrial sources of ZnS particles other than TC. It is 

also possible that TC particles may be generated from traffic tire wear with airborne 

transportation to and across the field and playground sites. 

93
Selected SEM Images and EDS Spectra of Tire Crumb Source Particles

Figure 1. TC particle showing smooth 

interior and rough exterior surfaces. Image 

was acquired in BSE mode in which particle 

brightness increases with atomic number. 

(Site F1)

Figure 2. Rough fractured exterior surface 

of TC particle. (Site F1). The carbonaceous 

matrix (darker) is sprinkled with bright 

crustal-like particles of aluminosilicates, 

quartz, and Fe-rich.

Figure 3a. Rough exterior surface and 

freshly cleaved interior surface. The bright 

features on the rough exterior surface are 

mostly super-micron crustal particles. 

(Site F4).

Figure 3b. The magnified image (upper 

right) is the area shown in the square in the 

low-mag image at left. The EDS spectrum 

was acquired at the spot located by the small 

box in the right-hand image (bright, 

rectangular particle just below center of 

image). The particle appears to be an 

Fe-rich aluminosilicate crustal particle. 

94
Figure 4a. Two TC particles showing 

smooth interior surface (upper particle) and 

rough exterior surface (lower particle) (Site 

P1). The EDS spectrum acquired in the 

exterior surface shows a matrix rich in S, Si, 

and Al with a trace of Fe and Zn. 

Figure 4b. Interior surface is much 

smoother and is not decorated with supermicron crustal particles. Spectrum shows 

S and trace of Zn. 

Figure 5. EDS spectrum was acquired from 

the bright, micron-sized Zn inclusion 

(zoomed image on right) in the interior 

surface of the tire crumb. (Site F1) 

Figure 6. EDS spectrum collected from the 

bright, micron-sized Zn inclusion (zoomed 

image on right) shows C, S, and Zn. 

95
Figure 7. EDS spectra of TC particles 

typically show C, S, and Zn. The spectrum 

was acquired from the bright inclusion at 

center of right-hand image. (Site F1) 

Figure 8. EDS spectrum from this TC 

particle showed no Zn in the TC matrix. 

(Site P1) 

Figure 9. EDS spectrum shows C, S and 

trace Zn in the interior surface of this TC 

particle. (Site P1) 

Figure 10. TC particle from shredded tire 

sample (Site P1) showing fibrous 

morphology. EDS spectrum shows only C. 

96
Selected SEM Images and EDS Spectra of Air PM10 Samples. 

Figure 11. Representative field image for 

Site F1 Location B sample. Magnification = 

600x. Tiny sub-micron black dots are pores 

in the polycarbonate filter. Sub-micron gray 

dots are sulfate particles. 

Figure 12. Representative field image for 

sample Site F1 Location A Duplicate 

sample. Magnification = 600x.

Site F1 Air PM10 Samples: Postulated TC Particles 

Figure 13. C-S-rich particle. Site F1 

Location B sample. 

Figure 14. C-S-Si-rich particle. Site F1 

Location B sample. Note the dull-gray, 

micron-sized sulfate particles.

97
Site F1 Air PM10 Samples: Postulated TC Particles 

Figure 15. C-Zn-S-rich particle. Site F1 

Location B sample, #224

Figure 16. C-Zn-S-Si-rich. Site F1 Location 

B sample, #306 

Figure 17. C-S-Si-Zn-rich. Site F1 Location 

B sample, #906 

Figure 18. C-S-Zn-Si-rich Site F1 Location 

B sample, #1060 

98
Site F1 Air PM10 Samples: Postulated TC Particles 

Figure 19. C-Zn-S-rich particle. Site F1 

Location A Duplicate sample, #179 

Figure 20. C-Zn-S-rich particle. Site F1 

Location A Duplicate sample, #794 

Figure 21. C-Zn-S-rich particle. Site F1 

Location A Duplicate sample, #1148 

Figure 22. C-Fe-Zn-S-rich particle. Site F1 

Location A Duplicate sample, #1241 

99
Site F1 Air PM10 Samples: Postulated TC Particles 

Figure 23. Site F1 Location A Duplicate 

sample, #1471 

Figure 24. Site F1 Location A Duplicate 

sample, #136 

Figure 25. Site F1 Location A Duplicate 

sample, #519

Figure 26. Site F1 Location A Duplicate 

sample, #153

100
Site P1 Air PM10 Samples: Postulated TC Particles 

Figure 27. Site P1 Location A sample, 

# 515 

Figure 28. Site P1 Location A sample, 

#1546 

Figure 29. Site P1 Location A sample, 

#1712 

Figure 30. Site P1 Location A sample, #162 

101
Site P1 Air PM10 Samples: Postulated TC Particles 

Figure 31. Site P1 Location A sample, 

#1500 

Figure 32. Site P1 Location A sample, #49 

Figure 33. Site P1 Location A sample, 

#1115 

Figure 34. Site P1 Location A sample, 

#1537 

102
Site P1 Air PM10 Samples: Postulated TC Particles 

Figure 35. Site P1 Location D sample, #834 Figure 36. Site P1 Location D sample,

#1065 

Figure 37. Site P1 Location D sample,

#1328 

Figure 38. Site P1 Location D sample,

#1370 

103
Site F4 Air PM10 Samples: Postulated TC Particles 

Figure 39. Fe-Zn-S-rich. Site F4 Location B 

sample, #146

Figure 40. Si-Al-Zn-Fe. Site F4 Location B 

sample, #761

Figure 41. S-K-Zn-Ca. Site F4 Location B 

sample, #1038

Figure 42. Si-Al-Zn-S-Fe. Site F4 Location 

B sample, #1561

104
105

Figure 43. Fe-Zn-S-Mn. Site F4 Location D 

sample, #2011

Figure 44. Zn-Fe-S-Si. Site F4 Location D 

sample, #2118

Figure 45. C-S. Site F4 Location D sample, 

#1480

Figure 46. S-Ti-Fe-Zn. Site F4 Location D 

sample, #2262