APPENDIX D 

First Reno Pilot Study 

Section 211(B) Tier 2 High-End Exposure Screening Study Of 

Baseline and Oxygenated Gasoline – Pilot Study 

Final Report 

Prepared for 

AMERICAN PETROLEUM INSTITUTE 

1220 L Street 

Washington, DC 20005-4070 

Prepared by 

Barbara Zielinska, John Sagebiel, Eric Fujita and Dave Campbell 

Desert Research Institute 

2215 Raggio Pkwy. 

Reno, NV 89512 

Jake McDonald 

Lovelace Respiratory Research Institute 

Inhalation Toxicology Laboratory 

P.O. Box 5890 

Albuquerque, NM 87185 

Tomas J.Kelly and Darrell W. Joseph 

Battelle 

505 King Avenue, 

Columbus, Ohio 43201 

June 13, 2002 
ii
ACKNOWLEDGMENT 

This work was supported by the American Petroleum Institute (API) and was conducted 

in coordination with the U.S. Environmental Protection Agency. We gratefully acknowledge the 

technical support provided by Dr. Will Ollison of the API and Dr. Ted Johnson of TRJ 

Environmental during the pilot study. 

iii
TABLE OF CONTENTS 

Acknowledgment ............................................................................................................................ ii 

List of Tables ................................................................................................................................. iii 

List of Figures................................................................................................................................ iv 

1. INTRODUCTION ................................................................................................................... 1-1 

1.1 Measurement Methods......................................................................................... 1-1 

1.2 Description of Microenvironments and Sampling Procedures............................1-2 

2. RESULTS ................................................................................................................................ 2-1 

2.1 Continuous Instruments....................................................................................... 2-1 

2.2 Integrated Samples............................................................................................... 2-2 

2.3 Solid Phase Microextraction (SPME).................................................................. 2-5 

2.4 Biological Samples .............................................................................................. 2-6 

2.4.1 Breath VOC Concentrations.................................................................... 2-6 

2.4.2 Urine VOC Concentrations...................................................................... 2-8 

2.5 Results of Additional Refueling Experiment (June 4, 2002, Reno) ..................2-10 

2.5.1 MS200 and Canister Results.................................................................. 2-11 

2.5.2 Breath Sample Results........................................................................... 2-11 

2.5.3 Analysis of Urinary VOC Concentrations............................................. 2-12 

3. RECOMMENDATIONS......................................................................................................... 3-1 

3.1 Exposure Measurements...................................................................................... 3-1 

3.2 Recommendations for Measurements of VOC in Breath ....................................3-2 

3.3 Recommendations for Measurement of VOC in Urine ....................................... 3-3 

4. REFERENCES ........................................................................................................................ 4-1 

iv
LIST OF TABLES 

Table 1.1 API S211 (b) Exposure Study-Reno Pilot Study ........................................................ 1-2 

Table 2.1 Canister and Tenax/Carbotrap Data............................................................................ 2-3 

Table 2.2 Comparison of MS200 with Canisters ........................................................................ 2-4 

Table 2.3 Comparison of Formaldehyde Data ............................................................................ 2-4 

Table 2.4 Concentrations (ppbv) of volatile organic compounds in breath and 

 microenvironments...................................................................................................... 2-7

Table 2.5 Urinary benzene concentrations in two subjects exposed to three 

 Microenvironments ................................................................................................... 2-10 

Table 2.6 Breath Data (ppbC) ................................................................................................... 2-13 

Table 2.7 Concentrations of Ethanol, MTBE & BTEX in urine samples (ng/L)...................... 2-16 

Table 3.1 Recommendation Summary........................................................................................ 3-1 

v
LIST OF FIGURES 

Figure 2-1 Concentration Time Series, Freeway AM ...........................................................F-1 

Figure 2-2 Concentration Time Series, Surface Streets.........................................................F-2 

Figure 2-3 Concentration Time Series, Freeway PM ............................................................F-3 

Figure 2-4 Concentration Time Series, Refueling In-Cabin..................................................F-4 

Figure 2-5 Concentration Time Series, Refueling out of cabin.............................................F-5 

Figure 2-6 Concentration Time Series, Walking Downtown ................................................F-6 

Figure 2-7 Concentration Time Series, Underground Garage...............................................F-7 

Figure 2-8 Concentration Time Series, Residential Garage Background A..........................F-8 

Figure 2-9 oncentration Time Series, Residential Garage Background B.............................F-9 

Figure 2-10 Concentration Time Series, Residential Garage Sample C ...............................F-10 

Figure 2-11 Concentration Time Series, Residential Garage Sample D ...............................F-11 

Figure 2-12 Concentration Time Series, Residential Garage Sample E................................F-12 

Figure 2-13 Concentration Time Series, Residential Garage Sample F................................F-13 

Figure 2-14 Concentration Time Series, Residential Garage Sample G ...............................F-14 

Figure 2-15 Concentration Time Series, Generator...............................................................F-15 

Figure 2-16 MS200 Raw and Corrected Data .......................................................................F-16 

Figure 2-17 MS200 Corrected Data Only .............................................................................F-17 

Figure 2-18 Correlation between CO by T15 and by Innova ................................................F-18 

Figure 2-19 Correlation between Innova and TEI for total hydrocarbons ............................F-19 

Figure 2-20 Innova vs. TEI for total hydrocarbons with three outliers removed..................F-20 

Figure 2-21 Correlation between CO and formaldehyde ......................................................F-21 

Figure 2-22 Correlation between DNPH and continuous formaldehyde...............................F-22 

Figure 2-23 Pre and post exposure breath samples during refueling.....................................F-23 

Figure 2-24 Pre and post exposure breath samples during in-cabin fueling..........................F-24 

Figure 2-25 Pre and post exposure breath samples during walk ...........................................F-25 

Figure 2-26 Relationship between full and alveolar breath...................................................F-26 

Figure 2-27 The three traces; benzene, toluene and sun of xylenes and 

 ethylbenzene ......................................................................................................F-27 

Figure 2-28 Data for BTEX and MTBE................................................................................F-28 

vi
1. INTRODUCTION 

 This report summarized the results of a pilot study that was conducted in Reno, NV, from 

February 25 through March 1, 2002 as part of a screening study of the high-end exposures to 

baseline and oxygenated gasoline. The study is being conducted for the American Petroleum 

Institute pursuant to Section 211(b) of the Clean Air Act. The objectives of the pilot study were 

to evaluate various monitoring methods under realistic field sampling conditions and to 

determine their suitability for use in the main exposure study to be conducted in Atlanta, 

Chicago, and Houston during the upcoming summer and winter seasons. We also evaluated 

biological sampling methods (breath and urine) for their applicability to the final study. In 

addition to DRI, personnel from Lovelace Respiratory Research Institute and Battelle 

participated in the pilot study. The refueling experiment was repeated on June 4, 2002 to 

evaluate the response of the portable mass spectrometer, which was not available for the 

refueling experiment during the pilot study. This report includes the results of the second 

refueling experiment. 

1.1 Measurement Methods 

 During the pilot phase of the study, we evaluated the sensitivity, precision, accuracy, 

selectivity, power requirements, and portability of sampling and monitoring devices to be used in 

the main study. The evaluations included methods for continuous measurement of carbon 

monoxide (CO), methyl tertiary butyl ether (MTBE), formaldehyde (HCHO), benzene, toluene, 

ethylbenzene, and xylenes (BTEX), with time integration of 1-5 minutes, and time-integrated 

measurements of ethanol (EtOH), 1,3-butadiene, and acetaldehyde (CH3CHO). The following 

continuous analyzers were used during the pilot study: 

Background CO, Monitor Labs. Research-grade non-dispersive infrared detection for carbon 

monoxide. This was maintained in the mobile lab and measured CO during our runs. Property of 

DRI. 

T15 CO, Langan products. Electrochemical monitor for CO. Quite small and portable, but it is 

temperature dependant. Property of DRI 

Photoacoustic Gas Monitor, Innova. A photoacoustic instrument that uses infrared light to 

detect CO and total hydrocarbons (calibrated as propane). In addition, this instrument could 

provide CO2 and water vapor (relative humidity). Property of Lovelace. 

Continuous Formaldehyde Monitor, Battelle. This instrument monitors formaldehyde in a 

continuous mode via a reaction to a fluorescent species and detection in a fluorimeter. Property 

of Battelle. 

Model TVA1000 FID, Thermo Environmental Instruments. This is a flame ionization based 

instrument for total hydrocarbons on a continuous basis. Sold primarily for leak detection at 

petrochemical plants. Property of TEI, on loan to DRI for the pilot study only. 

MS200, Kore Technologies. An electron impact ionization time-of-flight mass spectrometer 

was used for the detection of VOC species. Rather than using a GC to separate species, this 

1-1
1-2

instrument uses software to quantify species by apportionment of their mass fragmentation 

patterns. Property of DRI. 

In addition to the continuous instruments, time-integrated samples were collected in 

stainless steel canisters and on 2,4-dinitrophenylhydrazine (DNPH)-impregnated silica gel 

cartridges and Tenax/Carbotrap solid adsorbent traps. These samples were collected over a onehour exposure period. The DNPH cartridges were sampled with a potassium iodide coated 

denuder to remove ozone. The canisters were analyzed by gas chromatography with flame 

ionization detection for BTEX, MTBE, 1,3-butadiene, and total nonmethane hydrocarbons. The 

extracts of the DNPH cartridges were analyzed by HPLC/UV for formaldehyde and 

acetaldehyde. The Tenax/Carbotrap samples were analyzed for EtOH. 

We also tested the solid phase microextraction (SPME) technique during the pilot study 

for the collection and analysis of BTEX, MTBE, ethanol, formaldehyde, and acetaldehyde. A 

100 μm (poly)dimethylsiloxane (PDMS) fibers and 75 μm Carboxen/(poly)dimethylsiloxane 

(CAR/PDMS) fibers were used for BTEX, MTBE, and ethanol and 65 μm 

PDMS/divinylbenzene (DVB) fiber that was impregnated with o-(2,3,4,5,6-pentafluorobenzyl) 

hydroxylamine hydrochloride (PFBHA) was used for carbonyl compound collection. The fibers 

were exposed in parallel for 15 to 30 min and were analyzed on a gas chromatograph with both 

FID and photoionization detector (PID). Some of the fibers were also analyzed by GC/MS. 

1.2 Description of Microenvironments and Sampling Procedures 

 A summary of the samples collected is presented in Table 1-1. This table details the 

samples that were taken and a brief summary of the conditions at the time of sampling. In 

addition, the following notes detail the experiments. For the three driving exposures, we also 

collected GPS data showing location and time. Unless noted otherwise, each run last one hour. 

These are presented in the appendix. 

In-cabin Freeway (R02022607), Run #1

 For the first 15 minutes, the sampling van drove south on US 395 from Parr Boulevard to 

south Reno. This was a stretch of high rush hour traffic. The second 15 minutes, the van drove 

north from south Reno to Parr Boulevard. This was a stretch of low rush hour traffic. This loop 

was repeated for the third and fourth 15-minute periods. Data were not collected for the Innova 

photoacoustic instrument due to a failure of the pump. Only limited, hand logged, data were 

available for the TEI FID because of a failure of the internal memory of that instrument. A few 

data points are missing due to power problems at the beginning of the run. 

In-cabin Surface Streets (R02022612), Run #2

 For the first 15 minutes, the sampling van drove within the “urban canyon” loop, 

consisting of south on Sierra, east on 4th, north on Virginia, west on 5th. (This made a total of 4 

left turns around the Silver Legacy Hotel/Casino.). The second 15 minutes, the van drove a 

surface street loop, consisting of going east on 4th to Wells, north on Wells to Oddie, south on 

Sutro, and west on 4th. The third 15 minutes began at 4th, went north on Center, stopped at 

 
Table 1-1. API S211(b) Exposure Study - Reno Pilot Study 

Run 

# Test ID Date 

Start 

Time 

End 

Time

Microenvironment Exposure Level Location/Activity Ventila

R02022607 02/26/02 0710 0810 In-cabin - freeway 395 from Parr to south Reno 

R02022607a 02/26/02 0710 0725 higher -stop & go SB 395 from Parr to south Reno R02022607b 02/26/02 0725 0740 lower - free flow South Reno to DRI via 395 R02022607c 02/26/02 0740 0755 higher -stop & go SB 395 from Parr to south Reno 

1 

R02022607d 02/26/02 0755 0810 lower - free flow South Reno to DRI via 395 

D&P-siinch, heoutsidebetwee

R02022612 02/26/02 1200 1300 In-cabin -surface streetsR02022612a 02/26/02 1200 1215 higher - urban canyon S on Sierra, E on 4th, N on Virginia, W on 

5th (4 left turns around Silver Legacy) 

R02022612b 02/26/02 1215 1230 mixed - cross I-80 w/o 

stopping) 

From urban canyon loop, go E on 4th to Wells, N on Wells to Oddie, S on Sutro, W on 4th 

R02022612c 02/26/02 1230 1245 transect across I-80 with 

10-min stop at bridge 

From 4th, N on Center, stop at bridge over I80 for 10 minutes, then go back to urban canyon loop 

2 

R02022612d 02/26/02 1245 1300 higher - urban canyon S on Sierra, E on 4th, N on Virginia, W on 

5th (4 left turns around Silver Legacy) 

D&P-siinch, heoutsidebetwee

R02022616 02/26/02 1600 1700 In-cabin - freeway 395 from Parr to south Reno R02022616a 02/26/02 1600 1615 lower - free flow SB 395 from Parr to south Reno R02022616b 02/26/02 1615 1630 higher -stop & go South Reno to DRI via 395 R02022616c 02/26/02 1630 1645 lower - free flow SB 395 from Parr to south Reno 

3 

R02022616d 02/26/02 1645 1700 higher -stop & go South Reno to DRI via 395 

D&P-siinch, heoutsidebetwee

R02022708 02/27/02 0810 0910 Refueling/in-cabin R02022708a 02/27/02 0810 0825 baseline Frontage Road just south of Gold Ranch window R02022708b 02/27/02 0825 0840 refueling/in cabin Gold Ranch Pump #10 window 

door on

R02022708c 02/27/02 0840 0855 refueling/in cabin Gold Ranch Pump #10 window 

once 

4 

R02022708d 02/27/02 0855 0910 refueling/in cabin Gold Ranch Pump #10 window 

1-3
Run 

# Test ID Date 

Start 

Time 

End 

Time

Microenvironment Exposure Level Location/Activity Ventila

R02022712 02/27/02 1200 1300 Refueling/outside 

R02022712a 02/27/02 1200 1215 baseline Trailer park south of Gold Ranch window R02022712b 02/27/02 1215 1230 refueling/outside Van at Gold Ranch Pump #10, filled Suburu 

with midgrade gas on Pump #9 

samplin

R02022712c 02/27/02 1230 1245 refueling/outside Van at Gold Ranch Pump #10, filled Corolla 

with regular on Pump #9, collected gasoline sample 

samplin

5 

R02022712d 02/27/02 1245 1300 refueling/outside Van at Gold Ranch Pump #10, filled Volvo 

with premium gas on Pump #9, collected gasoline sample 

samplin

R02022811 02/28/02 1100 1200 Pedestrian walk 1 square block around Silver Legacy R02022811a 02/28/02 1100 1115 Virginia St between 4th and 5th (southbound)R02022811b 02/28/02 1115 1130 4th between Virginia and Sierra (westbound)R02022811c 02/28/02 1130 1145 Sierra between 4th and 5th (northbound) 

6 

R02022811d 02/28/02 1145 1200 5th between Sierra and Virginia (eastbound) R02022815 02/28/02 

1500 1600 Garage underground 

R02022815a 02/28/02 1500 1515R02022815b 02/28/02 1515 1530R02022815c 02/28/02 1530 1545

7 

R02022815d 02/28/02 1545 1600

Survey surrounding area, enter garage and survey upper level. Paused for 15 min to allow traffic to build up, then sampled for 1 hour. 

D&P-siwith hevent opgaragedinside gopen w

R02030109 03/01/02 0935 1340 Garage residential R02030109a 03/01/02 0935 1005 Background 1 R02030109b 03/01/02 1005 1035 Background 2 R02030109c 03/01/02 

1110 1140

Pull car in gar. open kitchen door 1 min and close 

R02030109d 03/01/02 1140 1210 Kitchen door open. R02030109e 03/01/02 1210 1240 Kitchen door closed, windows open 

8 

R02030109f 03/01/02 1240 1310 Open garage door and let icar dle for 30 min. 

open door to kitchen for 1 minute and keep close for remainder of period. 

Use houof room garage continumin cycand kitcthrough 

1-4
1-5

R02030109g 03/01/02 1310 1340 Post Exposure, back car out and close garage 

door 

Run 

# Test ID Date 

Start 

Time 

End 

Time

Microenvironment Exposure Level Location/Activity Ventila

R02030116 03/01/02 1600 1630 Generator Exhaust R02030116a 03/01/02 1600 1605 Exhaust downwind (CO ~ 2-3 ppm) R02030116b 03/01/02 1605 1610 Exhaust upwind (CO peak of 150 ppm) R02030116c 03/01/02 1610 1615 Exhaust downwind (CO <10 ppm) R02030116d 03/01/02 1615 1620 Exhaust upwind (CO 10-50 ppm) R02030116e 03/01/02 1620 1625 Exhaust upwind (CO 20-150 ppm) 

9 

R02030116f 03/01/02 1625 1630 Exhaust downwind (CO <5 ppm) 

10 R02060410 06/04/02 1010 1101 Refueling/outside 

R02060410a 1010 1025 Parking west of Gold Ranch- background SamplinR02060410b 1031 1046 At Gold Ranch Pump#10, refueling Volvo (4 

min) with premium gas on Pump #10 Samplin

R02060410c 1047 1101 At Gold Ranch Pump#10, refueling Corolla 

(2 min) with regular on Pump#9 Samplin
bridge over I-80 for 10 minutes, then went back to the urban canyon loop. The van door was 

open during the stop at the freeway overpass. For the fourth 15 minutes, the sampling van drove 

the “urban canyon” loop again, completing another 4 turns around the Silver Legacy 

Hotel/Casino. Data were collected from all instruments , but the MS200 instrument shut down 

during the run due to vacuum becoming too low. 

In-cabin Freeway (R02022616), Run #3

 For the first 15 minutes, the sampling van drove south on US 395 from Parr Boulevard to 

south Reno. This was a stretch of low rush hour traffic. The second 15 minutes, the van drove 

north from south Reno to Parr Boulevard. This was a stretch of high rush hour traffic. This loop 

was repeated for the third and fourth 15-minute periods. Data were collected from all 

instruments, but a few data points are missing due to power problems at the beginning of the run. 

In-cabin Refueling (R02022708), Run #4

 For both refueling experiments a rural but high volume service station was used. The 

station is located near a major interstate (I-80), but is otherwise in a rural area. The station has 18 

fueling pumps and sells between 20,000 and 40,000 gallons of gasoline per day. The mangers 

indicated they are the largest gasoline seller in northern Nevada. 

For the first 15 minutes, the sampling van parked on the frontage road, near the I-80 

freeway, away from the filling station to collect a background sample. The goal was to be 

approximately the same distance from the freeway as we would be at the fueling station. For the 

next 50 minutes, samples were collected while the van was parked at pump number 10, the 

center pump of the center island. Most equipment worked well, except that the MS200 had 

vacuum problems and had to be shut down. 

Refueling at Pump (R02022712), Run #5

 Similarly as with the first experiment, during the first 15 minutes, the sampling van 

parked on the frontage road, near the I-80 freeway, away from the filling station to collect a 

background sample. For the next 45 minutes, samples were collected in the breathing zone while 

the van was parked at pump 10, center of the center island. Breathing zone was at pump 9 

(opposite side of a dual-side pump), while three cars were filled with fuel. First was a Subaru 

that was filled with regular. Next came a Toyota that was filled with mid-grade, and finally was a 

Volvo filled with super. No formaldehyde data were collected due to power failure. In addition, 

the MS200 was not run due to vacuum problems. 

Refueling at Pump, Repeated (R02060410), Run #10

During the first 15 min the vehicle with sampling equipment was park on the quiet 

parking area, west of Gold Ranch and away from the filling station to collect a background 

sample. Only MS and SPME samples were collected. For the next 30 minutes, samples were 

collected in the breathing zone while the vehicle with sampling equipment was parked at pump 

10, center of the center island. Breathing zone was either at pump 10 or at pump 9 (opposite side 

of a dual-side pump), while two cars were filled with fuel. First was a Volvo filled with super, 

1-6
and next came a Toyota Corolla that was filled with regular grade. During 30 min one canister 

sample and two 15 min SPME samples were collected. MS200 was operating in a continuous 

mode. 

Pedestrian Walk (R02022811), Run #6

 All the monitoring equipment was placed on two mobile carts with batteries and 

inverters. For one hour, monitoring was conducted while the carts were slowly pushed around a 

large one square block area of central downtown Reno (the Silver Legacy Casino). The block 

was split roughly into equal times with approximately 15 minutes spent on each leg of the block. 

We started at 4th and Virginia, went south on Virginia, then west on 5th to Sierra, then north to 4th

and back to the starting point. 

 Data was collected from all instruments, except that for the first 15 minutes, no 

formaldehyde data was collected possibly due to a light leak in the fluorescence detector. In 

addition, the TEI FID did not collect data, although it appeared to be on the entire time. The 

reason for this failure was never determined. 

Underground Public Parking Garage (R02022815), Run#7

 The van was parked in an underground parking garage for one and a half hours during the 

period of maximum car departure. This garage has two underground levels, however the van 

remained on the upper of these two levels for two reasons. The first is that this level was nearly 

full while the lower level had only a few vehicles. The second reason is that the traffic ramps in 

the garage would allow travel from the first underground level down to the second, but from the 

second level the van could only go up to the surface, not back to the first underground level. The 

van’s position was relocated several times to try and capture the cold start exhaust from 

departing vehicles. Data were collected for the first 15 minutes, followed by a 15 minute zeroing, 

and then data collection for the next hour. 

Residential Kitchen and Garage without Car (R02030109a,b), Run #8

 For both residential exposures a home was used that had an attached two-car garage. The 

home and the garage share a common wall and there is a door from the garage into the kitchen. 

For the duration of these experiments a vented 2.5 gallon gasoline storage container was also 

present in the garage during the sampling period, located in the front center portion of the garage, 

closest to the house. The can was approximately half-full and the vent on the gas can was open. 

The sampling equipment was set up in a residential kitchen next to the door of the attached 

garage. For the first hour, the sampling was done with the garage door closed and no car. 

Samples were taken alternately for 10 minutes in the kitchen followed by 10 minutes in the 

garage for one hour. 

Residential Kitchen and Garage with Car (R02030109c-g), Run #8

 For these experiments the car used was a 1984 Honda Accord with a four-cylinder engine 

and it is carbureted. The vehicle is normally fueled with regular gasoline and annually passes the 

state smog check with no problems. Prior to parking the car in the garage, it was driven 

approximately 5 miles to warm the engine up. Once parked in the garage, the air cleaner cover 

1-7
was removed, exposing the inlet of the carburetor and the oil filler cap on the valve cover was 

removed to allow additional evaporative emissions. 

The sampling equipment had the same setup as the background samples. Separate 

integrated samples were collected in the garage and in the kitchen. The continuous instruments 

were switched between the garage and the kitchen at 10-minute intervals for 2.5 hours. The 

sequence of activities was as followed: 

 

Time Activity 

1110 1140 Pull car in gar. open kitchen door 1 min and close 

1140 1210 Kitchen door open. 

1210 1240 Kitchen door closed, windows open 

1240 1310 Open garage door and let car idle for 30 min. Open door to kitchen for 1 

minute and keep closed for remainder of period. 

1310 1340 Post Exposure, back car out and close garage door 

Sample probe was on the following sequence: 

garage 11:10-11:20 

kitchen 11:20-11:30 

garage 11:30-11:40 

kitchen 11:40-11:50 

garage 11:50-12:00 

kitchen 12:00-12:10 

kitchen 12:10-12:20 

garage 12:20-12:30 

kitchen 12:30-12:40 

garage 12:40-12:50 

kitchen 12:50-13:00 

garage 13:00-13:10 

garage 13:10-13:20 

kitchen 13:20-13:30 

garage 13:30-13:40 

Generator Exhaust (R02030115), Run #9

 In the DRI staging lot, the exhaust hose of a gasoline powered electrical generator was 

operated near the inlet of the sampling equipment. The generator exhaust hose was moved to a 

different location every 5 minutes. Adjusting its position relative to the instrument inlets; first 

downwind, then upwind, downwind, upwind, upwind closer to exhaust, and finally downwind. 

1-8
2. RESULTS 

 The results from this study are presented in four parts: 1) continuous (or semicontinuous) instruments; 2) integrated samples; 3) SPME samples; and 4) biological samples. 

Where appropriate, comparisons are made between the continuous and the integrated samples. 

Results from the additional refueling experiment performed in June 2002 in Reno are 

summarized in Section 2.5. 

2.1 Continuous Instruments 

Figures 2-1 through 2-15 present the time series for the continuous analyzers. For the 

residential garage exposures (2-8 through 2-15) the plots are only 30 minutes, not 60 minutes as 

for the rest of the plots. This is because of the number of changes that took place during these 

exposures. Also, during the residential garage exposures, the sample probe was moved to 

measure the kitchen area and the garage area as per the schedule listed above in the description 

of the runs. This accounts for the sudden changes in concentration seen in the data. 

The MS200 data is not presented in these time series. When we examined the raw MS 

data, without background correction, we found very high concentration levels being reported. 

The MS200 data appear high during all runs, especially compared to the integrated canister data, 

however, the structure of the data suggests that the MS200 is accurately responding to changes in 

ambient concentrations. Additional work was conducted with this instrument to help explain this 

effect. As a result of this work and discussions with the manufacturer (Kore), we have been able 

to better understand these data. The data that the MS200 reports is very dependent on the blank 

level. In addition, the membrane-based inlet and the relatively slow pumping mechanism appear 

to have the effect of slowing the 2-3 minute recovery time of the instrument, especially when the 

instrument is challenged with a high concentration. To test this we alternatively applied a high 

concentration standard and a zero air to the inlet of the MS200. On the basis of these 

experiments, we applied a correction that consisted of subtracting a background value consisting 

of a linearly sloping zero to the data, based on our experiments with the standards. This was 

difficult in the case of the residential garage where the instrument was switched every 10 

minutes between the relatively high concentrations in the garage with the much lower levels seen 

in the kitchen. However, once these backgrounds were subtracted, the MS200 data generally 

showed agreement (within a factor of 2 at ppb levels) with the canister data, which will be 

discussed later. We are still working with Kore to develop a pre-concentrator inlet that will allow 

for a much lower detection limit, however, this will sacrifice time resolution. 

An example of the correction applied is in chart 2-16 which shows the original benzene 

concentration, the zero function applied and the resulting corrected benzene concentration. The 

next figure, 2-17 shows the corrected data from this run for benzene, toluene, and the xylenes. In 

this chart, it is clear that the corrected plots track each other in structure, as we expected. The 

other data sets were similarly corrected and are summarized in Table 2-1 with the canister data. 

The comparison with the canister is quite favorable, except in the case of benzene at very low 

concentrations and in some runs where limited data was available. This was generally due to 

problems with the vacuum system in the MS200. 

2-1
2-2

 To compare the responses of the various instruments, we produced scatter plots, Figures 

2-18 through 2-21. Figure 2-18 shows the comparison between the Innova CO and the T15 CO. 

There is reasonable agreement, but especially at lower concentrations, we find that the Innova 

occasionally is much higher than the T15. This may be due to the method the Innova uses, which 

is to take a grab sample into its internal chamber, measure the components of interest and then 

evacuate the chamber. If this grab sample is during a particularly high brief instant, this may 

result in the higher response seen. 

 Figure 2-19 compares the two continuous hydrocarbon (HC) measuring devices, the 

Innova and the TEI. There are two very high values from the Innova, which Figure 2-20 

removes. The Innova data are adjusted upward by 10 to account for the expected difference in 

response from the photoacoustic vs. the FID. These two instruments use fundamentally different 

methods to measure hydrocarbons and may be hard to compare. In general, the two are tightly 

correlated, despite the different response factors. 

 The correlation between the Battelle continuous formaldehyde monitor and the T15 CO is 

presented in Figure 2-21, without the data from the generator which was significantly higher and 

dominated the plot. This shows a weak correlation, but includes some very high values. At more 

ambient concentrations, they are slightly better correlated. We should expect that these two 

would be correlated as they both are combustion-derived. 

2.2 Integrated Samples 

 Integrated samples consist of canisters, DNPH cartridges (for aldehydes) and 

Tenax/Carbotrap solid adsorbent traps. Canister data and Tenax/Carbotrap data for ethanol are 

presented in Table 2-1. In addition to the values measured, we show the sum of the BTEX 

compounds. Of interest was to compare these values to the MS200; this comparison is presented 

in Table 2-2. In this table, the average values (canister) from the various exposures are presented 

along with the corrected MS200 values for these same exposures. The corrected data are 

calculated as described above (Section 2.1). Generally the averages agree better at higher 

concentrations, but lower concentrations are quite reasonable, considering we are working at or 

near the detection limit of the MS200. In the case of the residential garage exposures this was 

further complicated by the 10-minute cycle time between the garage (at high concentrations) and 

the kitchen (at much lower concentrations). In spite of all this, the correlations between the 

canister and the MS200 were on the order of r2 ~ 0.87 and the slopes were ~0.75, with the 

MS200 reporting less than the canisters. 

 The DNPH samples were compared with the averaged data from the Battelle continuous 

formaldehyde sampler. This comparison is presented in Table 2-3 and Figure 2-22. The 

agreement is excellent for the 10 samples that are comparable. The correlation suggests that the 

Battelle unit is reading about 15% less than the DNPH cartridges are reporting. 
Table 2-1: Canister and Tenax/Carbotrap Data (concentrations in ppbv) 

Test ID Date Location 

1,3-

butadiene

Ethanol 

(T/C) MTBE benzene toluene

ethyl 

benzene

m/p

xylen

R02022607 2/26/02 

Morning Freeway Commute 1.02 0.79 0.07 4.32 10.77 0.95 3.65 

R02022612 2/26/02 

Urban canyon, surface 0.55 0.13 0.04 1.79 6.08 0.63 2.35 

R02022616 2/26/02 

Afternoon Freeway Commute 0.68 Missing 0.04 2.24 5.82 0.53 1.94 

R02022708 2/27/02 In van, gas station 0.16 nd 0.12 1.14 6.72 0.63 2.63 R02022712 2/27/02 

Gas station, refueling 1.58 nd 2.06 10.37 53.38 2.93 12.0

R02022811 2/28/02 pedestrian walk 0.16 0.47 0.01 0.69 2.29 0.22 0.85 

R02030109a 3/1/02 

Res. Garage, background 0.03 Missing 0.03 0.29 1.67 0.31 1.15 

R02030109b 3/1/02 Kitchen, background 0.03 Missing 0.01 0.31 1.25 0.13 0.49 

R02030109c 3/1/02 Residential garage 0.22 0.98 0.95 9.53 164.44 11.18 48.1

R02030109d 3/1/02 Kitchen 0.10 nd 0.36 3.66 55.34 3.60 15.5R020301016 3/1/02 

Mobile gas generator 17.38 nd 0.58 41.03 123.23 9.95 34.2

2-3

Nd = not detected Missing – missing sample 
2-4

Table 2-

Date

Table 2-3. Comparison of Formaldehyde Data

Date Time Test ID DNPH-HCHO Battelle-HCHO

2/26/02 0710 R02022607 6.66 7.92/26/02 1200 R02022612 9.66 7.92/26/02 1600 R02022616 6.84 6.22/27/02 0810 R02022708 4.13 5.52/27/02 1200 R02022712 4.622/28/02 1100 R02022811 2.30 1.12/28/02 1503 R0202815 4.96 3.5

3/1/02 0935 R02030109a 3.56 4.63/1/02 0935 R02030109b 2.393/1/02 1110 R02030109c 6.27 5.43/1/02 1110 R02030109d 4.15 5.23/1/02 1600 R020301016 23.29 20.7

2. Comparison of MS200 with Canisters

Canisters Summary 

Location benzene toluene ethyl benzem/p-xylene o-xylene Sum Xylenes Benzene 

Morning Freeway Commute 4.32 10.77 0.95 3.65 1.28 4.93 4.38 Urban canyon, surface 1.79 6.08 0.63 2.35 0.86 3.20 9.20 

2/26/022/26/02 

2/26/022/27/02 

Afternoon Freeway Commute 2.24 5.82 0.53 1.94 0.70 2.65 12.53 

In van, gas station 1.14 6.72 0.63 2.63 0.99 3.62 9.17 

2/27/02 2/28/02

3/1/023/1/023/1/023/1/023/1/02

Gas station, refueling 10.37 53.38 2.93 12.00 3.96 15.96 

pedestrian walk 0.69 2.29 0.22 0.85 0.31 1.16 3.11 Res. Garage, background 0.29 1.67 0.31 1.15 0.50 1.65 2.57 

Kitchen, background 0.31 1.25 0.13 0.49 0.20 0.69 8.69 Residential garage 9.53 164.44 11.18 48.17 17.39 65.56 9.30 

Kitchen 3.66 55.34 3.60 15.54 5.68 21.22 13.95 

Mobile gas generator 41.03 123.23 9.95 34.21 12.16 46.37 38.33 
2.3 Solid Phase Microextraction (SPME) 

 We tested the SPME technique during the pilot study for the collection and analysis of 

BTEX, MTBE, ethanol, formaldehyde, and acetaldehyde. A 100 μm (poly)dimethylsiloxane 

(PDMS) fibers and 75 μm Carboxen/(poly)dimethylsiloxane (CAR/PDMS) fibers were used for 

BTEX, MTBE, and ethanol and 65 μm PDMS/divinylbenzene (DVB) fiber that was 

impregnated with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was 

used for carbonyl compound collection. The fibers were exposed in parallel for 15 min, with 

exception of the residential garage microenvironment where the fibers were exposed for 30 min. 

The fibers were analyzed by injection into a GC housed in the mobile laboratory. Some of the 

fibers were also analyzed by GC/MS. The analysis was performed immediately after collection, 

when possible. However, some of the fibers had to be stored on dry ice in the cooler for a period 

of several hours. 

The initial SPME results from the pilot study are more qualitative than quantitative. The 

technique is new method for us and requires additional calibration work in the laboratory. Our 

major findings from the pilot study include: 

• 75 μm CAR/PDMS fibers are more sensitive than 100 μm PDMS fibers and are thus 

more suitable for ambient measurements. We will be using 75 μm PDMS fibers in the 

main study for the measurements of MTBE and BTEX. 

• Although ethanol peak was observed in all chromatograms, the ethanol concentrations 

were clearly too high. This is most probably due to the adsorption of ethanol from breath 

into the fibers. We measured up to 200 ppbv of ethanol concentration in the breath 

samples collected during this pilot study. The fibers were situated in the breathing zone 

during each experiment. 

• Formaldehyde and acetaldehyde concentrations are too high as well when compared with 

continuous formaldehyde analyzer data and integrated DNPH cartridge data. This may 

also be due to the presence of acetaldehyde in breath (we measured up to 25 ppbv of 

acetaldehyde in the breath samples). In addition, formaldehyde may be present in the 

mobile lab where the PFBHA impregnation of the PDMS/DVB fibers took place. We are 

getting the continuous formaldehyde analyzed from Battelle, thus we do not see any need 

to monitor formaldehyde with SPME technique and we propose to drop this analysis. 

Acetaldehyde data are less important for this study and we will obtain this data from 

integrated DNPH cartridge method. 

In summary we are still working on the development of the standard procedures for the 

SPME technique. The calibration, storage, and optimal sampling time are being addressed. We 

will be ready for the main study starting in June and we propose to use the SPME method for 

measurements of BTEX and MTBE. 

2-5
2-6

2.4 Biological Samples 

2.4.1 Breath VOC Concentrations 

Breath concentrations are portrayed in Table 2-4 and Figures 2-23 through 2-25 for two 

separate subjects during three separate scripted exposures. For the pilot project the subjects were 

two of the technicians collecting samples for micro-environmental concentrations. The 

objectives of this pilot program for the breath monitoring were to 1) evaluate the ability to 

analyze breath concentrations of VOC’s according to methods developed by Pleil and Lindstrom 

(1995), 2) to see differences between full and alveolar breath collections, 3) to assess breath 

concentrations between two subjects prior to and after scripted environmental exposures, and 4) 

to develop a recommendation for the final sampling protocol and biological monitoring 

technique of choice. All of the samples shown and discussed are “alveolar” samples unless 

designated as “full-breath” samples. Alveolar samples were collected to represent material that 

has undergone gas exchange in the lung. These samples were collected by breathing the end part 

of a breath directly into an evaculated cylinder (1 or 3L). The results of the breath measurements 

are described below. 

Refueling

Subject 7: The out of cabin re-fueling experiment showed the highest average exposure 

concentrations for all of the samples where biological samples were collected, by at least a factor 

of 5 for most analytes. As expected from results published by Philips and Greenberg (1992), all 

of the analytes (except MTBE) show a negative alveolar gradient (concentration in breath lower 

than ambient air) relative to the average exposure concentrations of 60 minutes. Unfortunately 

there is no real time data for these compounds, and the elimination rate via breath is rapid 

enough that real-time levels towards the end of exposure would be most important for these 

compounds. For subject 7 there is an observed exposure effect, with post exposure alveolar 

concentrations higher than pre-exposure concentrations by at least a factor of 2. With the 

exclusion of MTBE and ethyl benzene, this exposure effect was not observed for most 

compounds in subject 3. Exposure for the outside refueling was terminated at 1300 hours. The 

mobile lab was located approximately 1-2 minutes walking distance away from the exposure 

area and the exposure subjects were also responsible for much of the sampling responsibilities. 

Expired breath was not collected from subject 7 until 1302, and not from subject 3 until 1304. 

These short differences in times between samples may explain the lack of an exposure effect 

observed in subject 3. This can be confirmed by the breath elimination half-lives published to be 

between 1 and 3 minutes for MTBE, benzene, and toluene (Lindstrom and Pleil, 1996). 

In-Cabin Refueling

Subject 7 was the only subject sampled for both pre and post samples of the in-cabin 

refueling exposure. With the exception of MTBE, there is no exposure effect. This is most 

likely due to the fact that the post-exposure breath sample was not collected until 0919, 9 

minutes after exposure. This may be enough time to eliminate back down to background levels. 
2-7

Table 2-

micro

Fu

Alv

microenmicro

Fu

Alv

4. Concentrations (ppbv) of volatile organic compounds in breath and micro-environments.

Sample Collection Time Location Subject MTBE benzene toluene ethylbenzen

Breath 800 In Cabin fueling PRE 7 0.32 0.92 2.05 0.33 

Breath 919 In Cabin fueling POST 7 0.79 0.82 1.92 0.33 

environment van, Verdi gas station microenviront conc. 0.12 1.14 6.72 0.63 

Breath 1149 Refueling PRE 7 0.35 0.75 1.74 0.33 

Breath 1302 Refueling POST 7 3.99 1.83 5.73 1.06 Breath 1415 Midday Background 7 0.08 0.58 1.41 0.00 

Breath 1150 Refueling PRE 3 0.22 1.34 2.62 0.00 

ll Breath 1304 Refueling POST 3 1.54 1.52 3.16 0.67 

eolar Breath 1305 Refueling POST 3 1.84 1.24 2.53 0.48 

vironment Verdi gas station, refuel microenviront conc. 2.06 10.37 53.38 2.93 

Breath 1415 Midday Background 3 0.47 1.10 2.26 0.55 

Breath 1422 Midday Background 7 0.80 0.76 1.83 0.00 

environment pedestrian walk microenviront conc. 0.01 0.69 2.29 0.22 

Breath 924 Morning Background 3 0.28 1.18 2.42 0.63 

Breath 1043 Walk PRE 3 0.69 1.56 0.00 0.65 Breath 1201 Walk POST 3 0.31 1.44 3.00 0.73 

Breath 1047 Walk PRE 7 0.79 0.99 2.34 0.41 

Breath 1200 Walk POST 7 0.32 0.84 2.18 1.16 

ll Breath 1623 Direct Exhaust Exposure 3 0.12 1.36 2.73 0.41 

eolar Breath 1623 Direct Exhaust Exposure 3 0.09 1.38 3.79 0.59 
Pedestrian Walk

Again for the pedestrian walk there is very little exposure effect observed from subject 3 

while subject 7 shows at least a factor of 2 increase in alveolar concentrations after exposure for 

ethyl benzene, m/p xylene, and o-xylene. Similar to the refueling samples, subject 3 was did not 

give their sample at the same time as subject 7. There was a one-minute difference between 

subject 3 (1201) and subject 7 (1200). There was a negative exposure effect for MTBE in both 

subjects, suggesting that pre-exposure background or residual subject concentrations are higher 

than the exposure. The un-observable exposure effect for benzene and toluene are not 

explainable, as the exposure to these compounds was actually higher than the compounds where 

an exposure effect was observed. 

Full versus Alveolar Breath

Figure 2-26 shows the relationship between full and alveolar breath. Full and alveolar 

breath are defined here by how the sample was collected. Full is the entire breath blown into the 

canister sample, while the “alveolar” breath consists of partially reserved tidal volume and some 

expiratory reserve. The alveolar sample is collected at the end of a regular breath. As observed 

the agreement between the two breath collection methods are reasonable, but vary slightly by 

analyte. Agreement is between 15-25% for MTBE, benzene and toluene; and about 40% for 

ethyl benzene and the xylenes. In general, the difference is higher for compounds where the 

concentrations are less, indicating some contribution from measurement uncertainty may affect 

observed differences. Since the observed concentrations are higher in the full breath samples 

(with the exception of MTBE), it is obvious that there are levels of these compounds in the 

“dead-space” region of the subject that has not undergone any gas exchange. CO2 measurement 

between the two samples shows a difference of 10%, which is 5% less than the difference 

observed by Pleil and Lindstrom (1995). 15% is the expected amount, based on a 15% dilution 

of a 1 liter tidal volume. The full and alveolar breath sample in this pilot study was taken from a 

3 liter evacuated canister, which is different than the 1 L canister used by the second subject and 

in the Pleil and Lindstrom paper. Additional experiments should be completed comparing 

full/alveolar breath CO2 dilution between the 1 and 3 liter canisters. 

2.4.2 Urine VOC Concentrations 

Urinary concentrations of MTBE, benzene, toluene, ethylbenzene, and the xylenes were 

measured for backgrounds and pre/post exposure levels in two subjects from three scripted 

exposures. Shown in Table 2-5 are the urinary concentrations of benzene, which was the only 

urinary constituent consistently above the analytical limit of quantitation of 100 ng/L. The 

objectives of this pilot study was to apply the technique of 1) Fustinoni (1999) to measure 

urinary volatile organic compounds, 2) to measure concentrations (and variability) in two 

separate subjects, and 3) to evaluate results in terms of their ability to relate to exposure 

concentrations. In the original proposal one objective was also to measure urinary creatinine 

levels. This was not conducted for this report because this is not conducted in the contemporary 

literature to report urinary concentrations of VOC’s. “Older” literature used to measure 

creatinine in order to normalize urinary components for dilution. The current belief is that this is 

not necessary. The benzene results are discussed below for each scripted exposure. 

2-8
In-cabin Refueling

Subject 3 had a high pre-exposure background (208 ng/L) prior to the in-cabin refuel. There was 

a negative exposure effect after the in-cabin exposure (<100 ng/L), and a higher concentration 

one hour after exposure (138 ng/L) than immediately after exposure. This sample was similar to 

the next pre-exposure concentration taken one hour later (120 ng/L). Subject 7 had both pre and 

post exposure levels for the in-cabin re-fuel that were below the detection limit of 100 ng/L (3 x 

baseline). 

Table 2-5. Urinary benzene concentrations in two subjects exposed 

to three micro-environents

Benzene

Time Date subject activity ng/L

520 227 3 background 118.3

520 227 3 background 141.8

755 227 3 preexpos in cabin refuel 208.1

920 227 3 postexpos in cabin refuel 90.4a

1010 227 3 mid background 139.8

1148 227 3 preexpos refuel 118.6

1308 227 3 post expos refuel 3.1a

1417 227 3 post expos refuel 166.3

1524 227 3 post expos refuel 465.8

1645 227 3 post expos refuel 1100.6

950 228 3 pre walk 276.7

1225 228 3 post walk 335.5

445 227 7 background 163.9

752 227 7 preexposin cabin refuel 26.4a

924 227 7 postexpos in cabin refuel 0.0a

1150 227 7 preexpos refuel 15.4a

1312 227 7 post expos refuel 11.4a

1424 227 7 post expos refuel 18.1a

1620 227 7 post expos refuel 101.8

545 228 7 background 0a

1229 228 7 prewalk 106.5

1415 228 7 post walk 131.0

a: below the limit of quantitation of 100ng/L

2-9
Refueling

Subject 3 showed a negative exposure effect immediately after exposure, but saw a 

steady increase in urinary benzene excretion throughout the day. Measurements were made 

approximately every hour until 1645, and the hourly concentrations were 166, 465, and 1100 

ng/L at 1417, 1524, and 1645, respectively. This indicates that for these samples the time course 

for urinary excretion is much slower than it is for breath, and there is a lag in the excretion. The 

exposure concentrations observed for subject 7 were all below 100 ng/L, with the exception of 

the post exposure sample collected at 1620, where the concentration was about 100 ng/L. These 

results are comparable to MTBE data reported by Lee and Weisel (1998) who showed an 

increase in urinary MTBE after exposure (1 ppm for 10 min) at about 1 hour, remaining about 

the same at 3.5 hours and dropping several-fold by 6 hours. 

Pedestrian Walk

There was a slight positive exposure effect for benzene in both subjects from the in-town 

walk. Subject 3 had a pre-exposure urinary benzene concentrations of 276 ng/L and postexposure concentrations of 335 ng/L, while subject 7 had levels of 106 and 135 ng/L. For both 

subjects the starting background was different, and their increase was approximately the same for 

this exposure. 

2.5 Results of Additional Refueling Experiment (June 4, 2002, Reno) 

This experiment was conducted in order to test the response of MS200 (since we were 

not able to operate the instrument during the refueling experiment in February) in this 

microenvironment and to repeat breath and urine testing to confirm the conclusions drawn from 

the pilot study. There were important differences between this refueling and the one conducted 

for the pilot study. Most importantly: 

• We only filled the canister during the actual exposure period of 30 min. During the pilot 

study, we filled the canister over 1 hour, which consisted of 15 min of background plus 

45 min of exposure. 

• Used one exposure subject rather than two. 

• Refueled two vehicles instead of three. 

• The MS200 data output was adjusted to sum the xylenes and ethyl benzene using a single 

library spectra. The reason for this is that there is very little difference between the 

spectra of these four compounds and we found that the software did not do well trying to 

separate them. 

In addition to the MS200 and the canister, we also collected 5 breath samples and 8 urine 

samples that were analyzed by LRRI. The five breath samples were: Pre test; 15 min into test; 

approximatelly 2 min post test; 5 min later; and 10 min later. The urine samples included: pretest; approximately15 min post exposure (no urinary output between these two); approximately 

2-10
every hour thereafter for 6 more hours. All the voids from the test subject between the hours of 

0730 and 1800 were collected. 

2.5.1 MS200 and Canister Results 

Figure 2-27 shows the time series of the concentrations of benzene, toluene and the sum 

of xylenes and ethylbenzene in parts per million by volume, ppmv. The data are one-minute 

averages recorded by the MS200. To convert this unit to canister data units (which are parts per 

billion of carbon or ppbC), multiply by the number of carbons and by 1000 to adjust ppm to ppb. 

For example, the highest spike seen (at appx 21 min) is 0.173 ppmv for toluene, which is 

equivalent to 1211 ppbC. Benzene in the same spike is 0.104 ppmv or 624 ppbC. Sum of xylenes 

highest reading at about 22 min is 0.135 ppmv or1080 ppbC. 

The averages of the MS200 data are in good agreement with the canister measurements. 

The data are as follows (units are ppbC): 

Compound MS200 (ppbC) Canister (ppbC) % error 

(difference/can value)

Benzene 128.2 142.1 9.7 

Toluene 413.8 438.4 5.6 

Sum Xyl+EBz 336.6 368.2 8.6 

2.5.2 Breath Sample Results 

As explained above, the breath samples were collected in 1-liter stainless steel canisters 

from one subject. Table 2-6 below lists the results obtained from these samples (the units are 

ppbC): 

Table 2-6 Breath Data in ppbC 

Site/Compound 

Pre refueling 

breath 

Middle of run 

breath 

Post exposure 

breath #1 (2 

min) 

Post exposure 

breath #2 (5 

min) 

Post exposure 

breath #3 (10 

min) 

sample_time (hr) 0945 1046 1103 1107 1111 

sample_date 6/4/02 6/4/02 6/4/02 6/4/02 6/4/02 

1,3-butadiene 0.21 0.83 7.46 0.44 0.41 

MTBE 0.00 3.03 1.34 1.91 1.14 

benzene 2.65 14.76 7.82 10.76 9.78 

toluene 5.98 47.32 123.54 27.59 25.17 

ethyl benzene 0.83 1.01 2.77 8.46 7.75 

m/p-xylene 2.61 14.12 18.77 28.75 46.36 

o-xylene 1.66 5.59 3.82 7.03 16.88 

2-11
 These data are consistent with the data obtained during the pilot study, confirming very 

short breath elimination half-lives of the compounds measured. In addition, this elimination time 

is different for every compound. Whereas benzene concentration is the highest in the middle 

point of the exposure, and declines significantly two minutes after exposure, toluene 

concentrations are the highest 2 min after exposure, declining sharply five minutes after the 

exposure. Thus, breath data obtained after an integrated exposure period of an hour will not 

accurately measure the biological uptake that occurs under variable condition during the 

exposure period. 

2.5.3 Analysis of Urinary VOC Concentrations 

Urinary concentrations of MTBE, benzene, toluene, ethyl Benzene, and the xylenes were 

analyzed utilizing the same methods described for the Reno pilot study protocol. In addition, for 

these data we analyzed urinary creatinine values and urinary ethanol. Creatinine values were 

obtained using a standard creatinine analysis kit on a Monarch 2000 clinical chemistry 

instrument. Ethanol data were obtained utilizing the same solid phase extraction fibers that were 

used for the other chemical species. 

 Table 2-7 lists the concentrations of measured species, including creatinine, and Figure 2-

28 shows the data for BTEX and MTBE. Urinary concentrations of all of the measured VOC’s 

except ethanol were present in detectable limits in most of the samples. The absence of ethanol 

may be due to the high detection limits of (0.5 ng/L) relative to the other analytes, which are 

detectable in much lower concentrations. If urinary ethanol is to be monitored in follow on 

studies additional method development will be conducted to decrease the limits of detection on 

this assay. 

Concentrations of the other volatile organics reported here are complicated by the 

relatively high concentration observed in the pre-exposure samples. Concentrations postexposure increased throughout the day for benzene and toluene, which is similar to what was 

observed in the pilot study. However, at their peak, the concentrations of these compounds were 

only slightly larger than the pre-exposure backgrounds. The concentrations observed in the urine 

for benzene were consistent with what was observed during the pilot study and in the literature, 

with values in the range of 100-200 ng/L. The concentrations post-exposure did not increase 

much beyond 200 ng/L for benzene. These low post-exposure concentrations are consistent with 

the results from subject 7. While the highest urinary concentrations for subject 7 in this study do 

not reach levels reported for subject 3 in the pilot study, subject 7 does show an increase in 

urinary benzene and toluene throughout the day, which is consistent with subject 3 in the pilot 

study. The currently reported results do show concentrations of toluene that are increased relative 

to benzene, which is consistent with the higher concentrations of toluene that the subject was 

exposed to. The toluene concentrations do not, however, increase well above the pre-exposure 

background concentrations. 

Creatinine was measured during this follow-on study in response to some criticism from 

an external reviewer that creatinine values would help determine concentration effects resulting 

from dilution. As reported in the pilot study report, the concentrations of urinary VOC’s in the 

contemporary literature are typically not normalized to creatinine concentration. One example of 

the rationale for not using creatinine correction is given in Albertine et al. (2001), where 

2-12
2-13

statistical relationships between exposure and urinary concentrations of butadiene biomarkers 

were more significant when not normalized. 
Table 2-7 

Concentrations of Ethanol, MTBE and BTEX in urine samples (ng/L) 

2-14

Re-do of Refueling Experiment Concentrations in ng/L 

Sample 

# Subject Time Date Description Ethanol MTBE Benzene Toluene 

Eth Benzene 

p/m xylene 

1 7 820 6/4/02 pre exposure-morning nd 0.024 0.165 0.265 0.062 0.05

2 7 1115 6/4/02 post exposure nd 0.052 0.103 0.112 0.039 0.033 7 1215 6/4/02 post exposure nd 0.030 0.135 0.149 0.057 0.054 7 1327 6/4/02 post exposure nd 0.033 0.089 0.135 0.047 0.045 7 1430 6/4/02 post exposure nd 0.021 0.143 0.202 0.051 0.036 7 1522 6/4/02 post exposure nd 0.017 0.203 0.283 0.042 0.047 7 1624 6/4/02 post exposure nd 0.009 0.238 0.279 0.051 0.048 7 1718 6/4/02 post exposure nd 0.013 0.106 0.114 0.046 0.04
3. RECOMMENDATIONS 

 This section describes the equipment and protocols we recommend for this program. We 

first summarize the equipment in Table 3-1 and then discuss each individually. 

Table 3-1 

Recommendation Summary 

Instrument Recommendation Notes 

Battelle HCHO Yes We have requested Battelle build one for DRI. 

Kore MS-200 Yes Needs protocol development and possibly 

preconcentrator. 

TEI TVA1000 No Not sensitive enough. 

Innova 

Photoacoustic 

No Grab sampling method; overlap with other 

instruments. 

Langan T15 CO Yes Need to develop temperature dependence. 

Integrated 

Samples 

Yes 

SPME Yes Would be used only for MTBE and BTEX 

3.1 Exposure Measurements 

Formaldehyde Monitor. The Battelle instrument appears to have performed quite well. We 

evaluated a similar commercial instrument made by Alpha Omega during a three-day evaluation 

period at the end of May 2002. The evaluation consisted of collocated measurements with our 

CO analyzer, Kore MS200 analyzer and integrated DNPH measurements using 

microenvironmental exposures similar to those used during the pilot study. Base upon the results 

of this evaluation, we concluded that the Alpha Omega HCHO monitor would be suitable for the 

main study. 

Kore MS200. The MS200 appears to have performed rather well in the pilot study. We are 

currently refining the protocol for using this instrument, based on the results from the field study 

as well as the results of many experiments we have conducted since that time. We hope to install 

an automated system for zeroing the instrument during the run times to confirm the zero point of 

the instrument as it changes during the day. In addition, we will be standardizing the zeroing 

procedure and are working on methods to automate the background subtraction process. We 

recommend the use of the instrument in the main study. 

TEI TVA1000. The TVA1000 is a FID based detector for total hydrocarbons. As such it 

responds approximately equally to the concentration of oxidizable carbon in the air. In the 

present experiment that means it has the challenge of measuring small amounts of the 

hydrocarbons of interest in the presence of a relatively high concentration of methane. In 

3-1
addition since there is no speciation, we are not obtaining any information about the relative 

contribution of any of the components. Also, the baseline is not very stable and we do not think it 

adds a lot of useful information. Our recommendation is to not use this instrument. 

Innova Photoacoustic. This instrument can measure CO, CO2, total hydrocarbons and water 

vapor (dew point). However, the instrument is not a true “continuous” monitor, but rather it takes 

grab samples, measures that sample and then takes another grab sample. This means that the 

value determined may not accurately represent the average over the time period it is applied to. 

We feel that a better way to obtain total hydrocarbons is to compare CO and BTEX from 

continuous instruments to the same compounds in the canisters. Our recommendation is to not 

use this instrument. 

Langan T15 CO monitor. This instrument appears accurate and easy to use in addition to being 

portable with very low power consumption. It is, however, temperature dependant and we will 

need to develop a temperature based calibration to maintain accuracy. In addition, it appears to 

have a slower response time, especially post-exposure to a high concentration, but this was only 

noticeable in the extreme case of the generator at DRI where concentration changes were over 

100 ppm in less than 1 minute. We do recommend using this instrument. 

Integrated Samples. We recommend collecting integrated samples as a check on the continuous 

samples and to get more detailed speciation of VOCs. The association between the continuous 

CO and BTEX data with the data from time-integrated measurements can provide estimates of 

the time series for species without feasible methods for continuous measurement such as 1,3 

butadiene, acetaldehyde, ethanol, MTBE, and total nonmethane hydrocarbons.. 

SPME. Based on our pilot study, we consider this technique as very promising. We propose to 

use SPME for MTBE and BTEX, but not for ethanol, formaldehyde and acetaldehyde. We are 

currently working on perfecting our calibration procedure. We are also performing the series of 

experiments to determine the optimal exposure time and the dependence of measured 

concentrations on storage conditions. 

3.2 Recommendations for Measurements of VOC in Breath 

During the pilot study breath concentrations of MTBE, benzene, toluene, ethylbenzene, and the 

xylenes was successfully conducted. Analysis of alveolar and full breath showed that the 

sampling technique to target alveolar breath excluded contributions of VOC’s present in the 

“dead-space” air present in a full breath because their concentrations were lower. Breath 

concentrations between the two separate subjects differed in many cases most likely because of 

slight differences in the time of sample collection. This is because the breath elimination halflives of the compounds measured are between 1 and 3 minutes (Lindstrom and Pleil, 1996), so 

slight differences in the time of collection can make large differences in observed breath 

concentrations. This can also explain why for many of the samples there was little or no 

exposure effect observed. These samples were generally collected minutes after the end of the 

exposures, after which much of the target compounds would have been eliminated. This effect 

was observed by Lioy et al. (1991), who saw little correlation with breath benzene concentrations 

and microenvironmental exposure concentrations, and attributed their lack of agreement to the 

short time course of benzene elimination via breath. 

3-2
 When collected in exposure environments where the concentrations are above 

background (e.g. refueling) there is an observable exposure effect when the sample is collected 

very close to the end of exposure. However, these breath concentrations will only reflect what 

the subject is exposed to in the last portion of the exposure, as the majority of the one-hour 

exposure will have been eliminated by the time the samples are collected. Therefore single 

breath measurements at the termination of exposures are not a good index of cumulative onehour exposures. Therefore, we do not recommend breath measurements for urban exposure 

experiments during the main study. 

3.3 Recommendations for Measurement of VOC in Urine 

The method of Fustinoni (1999) based on a sensitive SPME technique was developed for 

application to this study. Work at LRRI was conducted with the same instrument as used in that 

study, but the published quantitation limits of 12-34 ng/L were not attainable. We were able to 

observe good signal/noise for all of the analytes in what would likely be the sensitivity range 

published by Fustinoni (1999). However, the deuterated internal standards utilized for 

quantitation had small amounts of the parent (un-deuterated) compound present that limited the 

limit of detection. The area counts of the parent compound in blanks showed integrated area 

counts from the mass spectrometer of approximately 600 for benzene, when the 100 ng/L 

standard had area counts of about 2500. The use of the internal standards is necessary to reduce 

sample to sample variability in the uptake of the VOC’s by the SPME fiber. 

Because of the low exposure concentrations observed in this study, the amount of urinary 

benzene and other VOC’s were extremely low. Although published excretion rates vary, a 

typical amount of un-metabolized benzene relative to exposure is on the order of 0.1% 

(Waidyanatha et al. (2001)). Fustinoni (1999) showed urinary concentrations of benzene to be 

around 114 ng/L after an approximate 3.5 ppb exposure, and Waidyanatha et al. (2001) have 

shown 145 ng/L concentrations in “non-exposed” subjects from an occupational exposure study. 

Similarly, Ghittori et al (1995) showed background levels of benzene in non-smokers of 

approximately 131 ng/L (geometric mean). Most of the urinary benzene concentrations observed 

in the currently reported pilot study are in the range of the low level exposures from previous 

studies described above. Since the scripted exposures were low there was no strong correlation 

between exposure and urinary benzene in the pilot study. This is slightly in contrast to published 

results of Waidyanatha et al. (2001), who saw an exposure effect with benzene, but the exposure 

concentrations were in the ppm range. 

After the highest exposure there was a relatively strong exposure effect observed in one 

subject and a lesser exposure effect observed in a second subject. There was a time course in the 

elimination of benzene that showed urinary benzene concentrations increasing with time. These 

results are comparable to MTBE data reported by Lee and Weisel (1998) who showed an 

increase in urinary MTBE after exposure (1 ppm for 10 min) at about 1 hour, remaining about 

the same at 3.5 hours and dropping several-fold by 6 hours. Here urinary concentrations were 

only measured 3 hours post exposure, so we were not able to observe the start of elimination 

from the body. Because of an inability to see the decay of urinary benzene after exposures, and 

the slight inconsistency in the two subjects (one showed much higher urinary benzene), we 

repeated this highest end exposure on June 4, 2002, to see if the urinary VOC concentration data 

3-3
can be linked strongly to an exposure effect at these levels and to see the full time course of 

elimination. 

Because the additional measurements of urinary MTBE/BTEX from the second refueling 

experiment were promising, we recommend this measurement as the biomonitoring technique of 

choice. We will pay special attention to the pre-exposure background urine sample collection, 

making sure that the subject is not exposed to gasoline exhaust at least 10 hours prior to sample 

collection. Since we were not able to discriminate urinary benzene concentrations in low-level 

exposures (e.g. walking down street), we propose to only conduct biomonitoring experiments 

from projected “high-end” exposures such as refueling. Monitoring will be conducted similar to 

the pilot study, with pre and post exposure collections of the subject’s urine. 

3-4
4. REFERENCES 

Albertini et al. (2001). Chem. Boil ineract. Vol 135-137, pg 429-453 

Fustinoni, S., R. Giampiccolo, S. Pulvirenti, M. Buratti, and A. Colombi (1999). Headspace 

solid-phase microextraction for the determination of benzene, toluene, ethylbenzene and 

xylenes in urine. J. Chromatogr. B 723: 105-115. 

Ghittori, S., Maestri, L., Fiorentino, M.L. and Imbriani, M. (1995). Evaluation of 

occupational exposure to benzene by urinalysis. Int. Arch. Occup. Environ. 

Health, 67, 195-200 

Lee, C.W. and C.P. Weisel (2001). Toxicokinetics of Human Exposure to Methyl 

tertiary-butyl ether (MTBE) Following Short-Term Controlled Exposures. J. 

Exposure Anal. And Environ. Epi., 11, 67-78 

Lindstrom, A.B., and J.D. Pleil (1996). Alveolar Breath Sampling and Analysis to Assess 

Exposures to Methyl Tertiary Butyl Ether (MTBE) During Motor Vehicle 

Refueling., J. Air and Waste Management, V. 46, p. 676-682 

Lioy, P.J., Wallace, L., and E. Pelizzari (1991). Indoor/Outdoor, and Personal Monitor 

and Breath Analysis Relationships for Selected Volatile Organic Compounds 

Measured at Three Homes During New Jersey Team, J. Exposure Anal. And Envir. Epi., 

Vol. 1, No. 1, pp 45-61 

Philips, M. and J. Greenberg (1992). Ion-Trap Detection of Volatile Organic Compounds 

in Alveolar Breath, Clin. Chem. 38/1, 60-65 

Pleil, J.D., and A.B. Lindstrom (1995). Collection of a Single Alveolar Exhaled Breath 

for Volatile Organic Compound Analysis., American J. Industrial Medicine, 28; 109-121 

Waidyanatha, S., N. Rothman, S. Fustinoni, M. T. Smith, R. B. Hayes, W. Bechtold, M. 

Dosemeci, L. Guilan, S. Yin, and S. M. Rappaport (2001). Urinary benzene as a 

biomarker of exposure among occupationally exposed and unexposed subjects. 

Carcinogenesis 22: 279-286. 

4-1
FIGURE FOR SECTION 2 
Figure 2-1 Concentration Time Series, Freeway AM 

Freeway AM (R02022607)

0.05.0

10.015.020.025.0

7:10

7:15

7:20

7:25

7:30

7:35

7:40

7:45

7:50

7:55

8:00

8:05

CO

HC & HCH

F-1
Figure 2-2 Concentration Time Series, Surface Streets 

Surface Streets (R02022607)

0.02.04.06.08.0

10.012.014.016.018.020.0

12:00

12:05

12:10

12:15

12:20

12:25

12:30

12:35

12:40

12:45

12:50

12:55

CO

0.02.04.06.08.010.012.0

HC & HCHO 

F-2
Figure 2-3 Concentration Time Series, Freeway PM 

Freeway PM (R02022616)

0.05.0

10.015.020.025.0

16:00

16:05

16:10

16:15

16:20

16:25

16:30

16:35

16:40

16:45

16:50

16:55

CO

0.02.04.06.08.010.012.0

HC & HCHO 

F-3
Figure 2-4 Concentration Time Series, Refueling In-Cabin 

Refueling In-Cabin (R02022708)

0.01.02.03.04.05.06.07.08.09.0

10.0

8:10

8:15

8:20

8:25

8:30

8:35

8:40

8:45

8:50

8:55

9:00

9:05

CO

0.01.02.03.04.05.06.07.0

HC & HCHO

F-4
Figure 2-5 Concentration Time Series, Refueling out of cabin 

Refueling Out of Cabin (R02022712)

0.01.02.03.04.05.06.07.0

12:00

12:05

12:10

12:15

12:20

12:25

12:30

12:35

12:40

12:45

12:50

12:55

CO

0.05.010.015.020.025.030.035.040.0

HC & HCHO 

F-5
Figure 2-6 Concentration Time Series, Walking Downtown 

Walking Downtown (R02022811)

0.01.02.03.04.05.06.07.0

11:00

11:05

11:10

11:15

11:20

11:25

11:30

11:35

11:40

11:45

11:50

11:55

CO

0.01.02.03.04.05.06.07.0

HC & HCHO

F-6
Figure 2-7 Concentration Time Series, Underground Garage 

Underground Garage (R02022815)

0.02.04.06.08.0

10.012.0

15:00

15:05

15:10

15:15

15:20

15:25

15:30

15:35

15:40

15:45

15:50

15:55

CO

0.01.02.03.04.05.06.07.08.09.0

HC & HCHO 

F-7
Figure 2-8 Concentration Time Series, Residential Garage Background A 

Residential Garage Background A (R02030109a)

0.00.10.20.30.40.50.6

9:35

9:40

9:45

9:50

9:55

10:00

10:05

CO

0.01.02.03.04.05.06.07.0

HC & HCHO

F-8
Figure 2-9 Concentration Time Series, Residential Garage Background B 

Residential Garage Background B (R02030109b)

0.00.10.10.20.20.30.30.40.40.50.5

10:05

10:10

10:15

10:20

10:25

10:30

10:35

CO

0.01.02.03.04.05.06.07.0

HC & HCHO

F-9
Figure 2-10 Concentration Time Series, Residential Garage Sample C 

Residential Garage Sample (R02030109c)

0.00.10.20.30.40.50.60.70.8

11:10

11:15

11:20

11:25

11:30

11:35

11:40

CO

0246811111

HC &HCHO 

F-10
Figure 2-11 Concentration Time Series, Residential Garage Sample D 

Residential Garage Sample (R02030109d)

0.00.10.20.30.40.50.60.70.80.91.0

11:40

11:45

11:50

11:55

12:00

12:05

12:10

CO

0.02.04.06.08.010.012.014.016.018.0

HC & HCHO 

F-11
Figure 2-12 Concentration Time Series, Residential Garage Sample E 

Residential Garage Sample (R02030109e)

0.00.10.20.30.40.50.6

12:10

12:15

12:20

12:25

12:30

12:35

12:40

CO

0.02.04.06.08.010.012.014.016.0

HC & HCHO

F-12
Figure 2-13 Concentration Time Series, Residential Garage Sample F 

Residential Garage Sample (R02030109f)

0.00.20.40.60.81.01.21.41.61.82.0

12:40

12:45

12:50

12:55

13:00

13:05

13:10

CO

0.02.04.06.08.010.012.014.0

HC & HCHO 

F-13
Figure 2-14 Concentration Time Series, Residential Garage Sample G 

Residential Garage Sample (R02030109g)

0.00.10.20.30.40.50.60.70.80.9

13:10

13:15

13:20

13:25

13:30

13:35

13:40

CO

0.01.02.03.04.05.06.07.0

HC & HCHO 

F-14
Figure 2-15 Concentration Time Series, Generator 

Residential Garage Sample (R02030116)

0.0

100.0200.0300.0400.0500.0600.0700.0800.0900.0

16:00

16:05

16:10

16:15

16:20

16:25

16:30

CO

0.020.040.060.080.0100.0120.0

HC & HCHO

Generator Sample (R02030116)

F-15
Figure 2-16 MS200 Raw and Corrected Data 

Freeway AM

MS200 Raw Benzene, Zero, and Corrected

-0.01

0

0.010.020.030.040.050.060.070.080.09

0.1

0.11

ppmv

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48 0:36:00 0:43:12 0:50:24 0:57:36 

Elapsed time

F-16
Figure 2-17 MS200 Corrected Data Only 

Freeway AM

MS200 Corrected Data Only

-0.01

0

0.010.020.03

ppmv

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48 0:36:00 0:43:12 0:50:24 0:

Elapsed time

F-17
Figure 2-18. Correlation between CO by T15 and by Innova. 

y = 0.8754x + 0.4195

R2 = 0.7709

02468

1012141618

Innova CO (ppm)

0

2

4

6

8 10 12 14 

T15 CO (ppm)

F-18
Figure 2-19 Correlation between Innova and TEI for total hydrocarbons. 

Chart Title

y = 0.0703x + 3.0835

R2 = 0.2878

02468

101214

0 20 40 60 80 100 

Innova HC as propane (ppm*10)

TEI HC as methane (ppm)

F-19
Figure 2-20 Innova vs.TEI for total hydrocarbons with three outliers removed. 

Chart Title

y = 0.209x + 2.4854

R2 = 0.6819

0.002.004.006.008.00

10.0012.0014.0016.0018.00

TEI HC as methane (ppm)

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 

Innova HC as propane (ppm*10)

F-20
F-21

Figure 2-21 Correlation between CO and formaldehyde. 

y = 0.5062x + 4.5338

R2 = 0.2621

02468

10121416

0 5 10 15 20 

T15 CO (ppm)

Battelle HCHO (ppb)
Figure 2-22 Correlation between DNPH and continuous formaldehyde. 

F-22

HCHO

y = 0.8543x + 0.6638

R2

 = 0.9532

15

20

25

25

le-HCHO

0

5

10

0 5 10 15 20

DNPH-HCHO

Battel
Figure 2-23. Pre and post exposure breath samples during refueling. 

Refueling 

01234567

mtbe benze tolue etbz mp_xyl o_xyl

ppbv

F-23
Figure 2-24 Pre and post exposure breath samples during in-cabin fueling. 

In-cabin Fueling

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

mtbe benze tolue etbz mp_xyl o_xyl

ppbvIn Cabi

In Cabi

F-24
Figure 2-25 Pre and post exposure breath samples during walk. 

Walk

0123456789

10

ppbv

mtbe benze tolue etbz mp_xyl o_xyl

F-25
Figure 2-26 Relationship between full and alveolar breath. 

Realationship Between Full and Alveolar Breath

0.000.501.001.502.002.503.003.50

MTBE benzene toluene ethylbenzene m/p xylene o-xylene

ppbvF

A

F-26
Figure 2-27 The three traces; benzene, toluene and sun of xylenes and 

 ethylbenzene 

Refuel

0

0.020.040.060.08

0.1

0.120.140.160.18

0.2

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48 

Elapsed time

ppmv

Benzene Toluene Sum xylenes+ethylbenzene

F-27
Figure 2-28 Data for BTEX and MTBE 

0.0000.0500.1000.1500.2000.2500.300

0 2 4 6 8

Sample Number

ng/L

MTBE Benzene Toluene Eth Benzene p/m xylene 

Pre-exposure Post exposure

F-28