1

Supplement to the Final Report: 

Section 211(B) Tier 2 High End Exposure Study of 

Conventional and Oxygenated Gasoline 

Prepared for 

AMERICAN PETROLEUM INSTITUTE 

1220 L Street 

Washington, DC 20005-4070 

Prepared by 

Barbara Zielinska, Eric M. Fujita, John C. Sagebiel, and David E. Campbell 

Division of Atmospheric Sciences 

Desert Research Institute 

Nevada System of Higher Education 

2215 Raggio Parkway 

Reno, NV 89512 
2

Section 1: Quantification of Personal Exposures to Motor Vehicle 

Emissions in High Exposure Microenvironments in Atlanta, Houston, 

and Chicago during Summer and Winter. 

Atlanta Summer 2002-2003

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME7 ME8 ME9 ME10 ME11 ME12 ME13

0

2

4

6

8

10

12

14

16

18

20

22

Maximum

Minimum

75%

25%

Median

Outliers

Extremes

Figure 1.3.1-1. Time-integrated exposure levels (ppbv) in different MEs in Atlanta, 

Summer 2002 and 2003. 

ME1 : In-cabin congested freeway; ME2: In-cabin urban canyon; ME3: In-cabin refueling; ME4: In-cabin underground garage; 

ME5: In-cabin toll plaza; ME6: In-cabin roadway tunnel; ME7: Out-of-cabin refueling; ME8:Out-of-cabin sidewalk; ME9: Out-ofcabin sidewalk/bus stop; ME10: Out-of-cabin surface parking; ME11: Out-of-cabin underground garage; ME12: Outside toll plaza; 

ME13: In-cabin trailing high-emitter vehicle

Atlanta Winter 2004

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME7 ME8 ME9 ME10 ME11 ME12 ME13

0

2

4

6

8

10

12

14

16

18

Maximum

Minimum

75%

25%

Median

Outliers

Extremes
3

Figure 1.3.1-2. Time-integrated exposure levels (ppbv) in different MEs in Atlanta, 

Winter 2004. 

ME1 : In-cabin congested freeway; ME2: In-cabin urban canyon; ME3: In-cabin refueling; ME4: In-cabin underground garage; 

ME5: In-cabin toll plaza; ME6: In-cabin roadway tunnel; ME7: Out-of-cabin refueling; ME8:Out-of-cabin sidewalk; ME9: Out-ofcabin sidewalk/bus stop; ME10: Out-of-cabin surface parking; ME11: Out-of-cabin underground garage; ME12: Outside toll plaza; 

ME13: In-cabin trailing high-emitter vehicle

Chicago Summer 2003

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME6 ME7 ME8 ME9 ME10 ME11 ME12

0

2

4

6

8

10

12

14

16

Maximum

Minimum

75%

25%

Median

Outliers

Extremes

Figure 1.3.1-3. Time-integrated exposure levels (ppbv) in different MEs in Chicago, 

Summer 2003 
4

Chicago Winter 2004

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME6 ME7 ME8 ME9 ME10 ME11 ME12

0

2

4

6

8

10

12

14

16

18

Maximum

Minimum

75%

25%

Median

Outliers

Extremes

Figure 1.3.1-4. Time-integrated exposure levels (ppbv) in different MEs in Chicago, 

Winter 2004. 

ME1 : In-cabin congested freeway; ME2: In-cabin urban canyon; ME3: In-cabin refueling; ME4: In-cabin underground garage; 

ME5: In-cabin toll plaza; ME6: In-cabin roadway tunnel; ME7: Out-of-cabin refueling; ME8:Out-of-cabin sidewalk; ME9: Out-ofcabin sidewalk/bus stop; ME10: Out-of-cabin surface parking; ME11: Out-of-cabin underground garage; ME12: Outside toll plaza; 

ME13: In-cabin trailing high-emitter vehicle

Houston Summer, 2004

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME6 ME7 ME8 ME9 ME10 ME11 ME12

0

1

2

3

4

5

6

7

8

9

10

Maximum

Minimum

75%

25%

Median

Outliers

Extremes
5

Figure 1.3.1-5. Time-integrated exposure levels (ppbv) in different MEs in Houston, 

Summer 2004. 

ME1 : In-cabin congested freeway; ME2: In-cabin urban canyon; ME3: In-cabin refueling; ME4: In-cabin underground garage; 

ME5: In-cabin toll plaza; ME6: In-cabin roadway tunnel; ME7: Out-of-cabin refueling; ME8:Out-of-cabin sidewalk; ME9: Out-ofcabin sidewalk/bus stop; ME10: Out-of-cabin surface parking; ME11: Out-of-cabin underground garage; ME12: Outside toll plaza; 

ME13: In-cabin trailing high-emitter vehicle.

Houston Winter 2005

Acetaldehyde

ME1 ME2 ME3 ME4 ME5 ME6 ME7 ME8 ME9 ME10 ME11 ME12

0

1

2

3

4

5

6

7

8

9

10

Maximum

Minimum

75%

25%

Median

Outliers

Extremes

Figure 1.3.1-6. Time-integrated exposure levels (ppbv) in different MEs in Houston, 

Winter 2005. 

Section 4: Relationships of Attached Garage and Home Exposures to 

Fuel Type and Emission Levels of Garage Sources 

Table 4.3-6. Summary of Background Concentrations in Kitchen and Garage. Units are 

ppbv, except as noted. 
6

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Kitchen Backgrounds

Summer 0.08 1.70 6.50 0.67 2.30 1.05 0.42 0.35 49.83 1215.58 13.57

Winter 0.21 3.93 7.47 4.82 7.47 4.32 1.31 0.87 13.51 5.47

Garage Backgrounds

Summer 0.02 2.68 8.87 0.92 3.25 1.14 0.20 0.15 20.29 6.28

Winter 0.12 2.29 5.40 0.85 3.13 1.21 1.11 0.78 7.70 2.65

Kitchen, all

Min 0.02 0.73 3.33 0.37 1.25 0.50 0.00 0.15 5.50 53.60 3.00

Max 1.33 11.76 15.49 38.21 32.27 24.64 6.16 5.29 106.63 2194.10 24.56

Garage, all

Min 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 3.85 0.90 1.20

Max 0.90 11.47 25.72 3.19 11.33 4.27 3.78 7.01 35.63 1475.60 13.89

Budi13 = 1,3BD; Benze = benzene; Tolue = toluene, Mp_xyl = m,p-xylene; o_xyl = o-xylene, 

Formal = formaldehyde; EtOH = ethanol, Acetal = acetaldehyde 

Table 4.3-7. Summary of Test Concentration Ranges in Kitchen and Garage. Units are 

ppbv, except as noted. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Kitchen, all

Min 0.02 0.18 2.49 0.25 0.78 0.43 0.00 0.00 0.00 158.80 0.00

Max 1.64 11.17 15.58 3.02 9.06 5.12 13.27 10.85 95.59 670.20 23.86

Garage, all

Min 0.03 1.33 2.48 0.39 1.25 0.51 0.00 0.20 0.00 5.80 0.00

Max 36.35 65.44 93.67 18.23 50.72 19.36 185.63 39.16 174.20 27.70 30.79

Table 4.3-8. Seasonal Impact on Observed Maximum Concentrations (Units are ppbv, 

except as noted). 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Kitchen Max-S 1.42 7.77 14.64 1.84 6.44 2.98 10.49 1.62 95.59 670.20 23.86

Max-W 1.64 11.17 15.58 3.02 9.06 5.12 13.27 10.85 54.78 15.51

Garage Max-S 36.35 65.44 93.67 18.23 50.72 19.36 93.63 28.60 174.20 27.70 30.79

Max-W 8.47 24.68 34.61 6.05 22.78 8.04 185.63 39.16 54.78 15.51

Table 4.3-9. Seasonal Impact on Observed Maximum Concentrations (Units are ppbv, 

except as noted), Normal Mode Vehicles Only. 

Normal Only Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Kitchen Max-S 0.29 4.87 14.35 1.80 6.44 2.48 1.59 0.81 95.59 519.70 23.86

Max-W 1.55 11.17 14.80 2.76 8.50 3.44 13.27 3.07 31.31 11.00

Garage Max-S 4.76 21.02 48.73 6.99 19.92 7.73 8.95 3.86 58.53 27.70 13.79

Max-W 8.47 24.68 34.61 6.05 22.78 8.04 185.63 39.16 54.78 15.51

Budi13 = 1,3BD; Benze = benzene; Tolue = toluene, Mp_xyl = m,p-xylene; o_xyl = o-xylene, 

Formal = formaldehyde; EtOH = ethanol, Acetal = acetaldehyde 

Table 4.3-10. Seasonal Impact on Observed Average Concentrations (Units are ppbv, 

except as noted), Normal Mode Vehicles Only. 
7

Normal Only Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Kitchen Ave-S 0.16 3.25 11.54 1.39 4.58 1.97 0.56 0.39 53.33 339.25 13.48

Ave-W 0.43 4.38 7.24 1.31 4.12 1.72 3.76 0.92 14.54 4.99

Garage Ave-S 1.87 8.72 20.36 3.06 8.67 3.51 2.47 1.82 26.44 17.35 6.26

Ave-W 2.35 8.15 14.44 2.54 9.00 3.39 36.64 6.45 18.72 4.79

Table 4.3-11. Effect of Fuel and Operational Mode of the Sedan on Observed Levels in 

the Kitchen and Garage (Units are ppbv, except as noted). 

Location Fuel Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Normal Garage Atlanta 0.55 2.40 6.09 0.98 3.24 1.38 0.82 0.31 7.16 1.78

Houston 0.95 3.56 9.78 1.51 5.20 2.08 10.81 0.56 22.25 5.11

Chicago 1.19 3.40 8.29 1.39 4.91 2.06 0.48 0.45 11.75 27.70 3.81

Kitchen Atlanta 0.06 2.01 8.42 1.03 3.61 1.45 0.10 0.10 63.45 16.78

Houston 0.24 2.82 7.49 1.10 3.69 1.59 3.35 0.52 24.01 6.65

Chicago 0.06 3.82 8.45 1.26 4.40 1.91 0.27 0.29 13.38 158.80 2.48

Malfunction Garage Atlanta 1.42 26.80 44.40 4.03 13.08 4.86 16.67 6.27 23.35 9.03

Houston 2.54 12.45 25.68 4.20 14.11 5.53 49.97 13.29 30.72 7.35

Chicago 1.92 9.54 11.26 1.65 5.64 2.18 1.13 12.16 13.08 19.00 7.35

Kitchen Atlanta 0.86 9.13 15.11 2.06 6.47 2.92 0.35 5.59 21.99 6.97

Houston 0.23 4.14 9.68 1.74 5.42 2.65 10.19 1.30 26.19 8.37

Chicago 0.23 2.81 6.04 1.03 3.51 1.53 0.30 0.76 25.93 670.20 9.88

Table 4.3-12. Effect of Fuel and Operational Mode of the Truck on Observed Levels in 

the Kitchen and Garage (Units are ppbv, except as noted). 

Location Fuel Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

Normal Garage Atlanta 2.40 11.28 26.45 3.79 11.05 4.32 0.44 2.13 38.17 8.25

Houston 1.39 9.69 24.99 3.83 11.12 4.46 10.46 2.15 38.12 8.85

Chicago 2.55 9.64 15.61 2.99 8.56 3.41 1.74 2.87 0.00 7.00 0.00

Kitchen Atlanta 0.12 1.65 8.23 0.83 2.58 1.04 0.10 0.28 35.68 8.88

Houston 0.37 4.57 9.68 1.62 4.85 2.28 7.20 0.82 45.47 13.40

Chicago 0.92 8.02 14.08 2.27 6.97 2.78 1.95 1.94 21.61 519.70 7.25

MalfunctionGarage Atlanta 3.74 16.19 26.42 3.87 12.22 4.58 0.38 8.03 45.11 9.79

Houston 22.41 45.06 64.14 12.14 36.75 13.70 139.63 33.88 114.49 23.15

Chicago 2.73 7.72 11.55 1.85 5.87 2.16 0.06 2.52 32.96 5.80 17.28

Kitchen Atlanta 0.24 3.25 7.65 1.99 5.67 3.15 0.13 0.68 42.56 10.91

Houston 0.80 4.23 9.05 1.42 4.25 1.89 4.57 1.33 52.72 14.55

Chicago 0.11 4.11 7.29 1.45 4.67 1.92 0.03 0.28 29.37 414.10 7.65
8

0

10

20

30

40

50

60

70

80

Budi13

Benze

Tolue

Etbz

Mp_xyl

O_xyl

MTBE

CO,ppm

Formal

EtOH

Acetal

compound

ppbv

Atlanta-N

Atlanta-F

Houston-N

Houston-F

Chicago-N

Chicago-F

Figure 4.3-1. Effect of fuel and mode on observed concentrations in the garage. The 

legend “N” is normal and “F” is malfunction. The 1,3-BD value for Houston-F is suspect. 
9

0

5

10

15

20

25

30

35

40

45

50

Budi13

Benze

Tolue

Etbz

Mp_xyl

O_xyl

MTBE

CO,ppm

Formal

EtOH

Acetal

compound

ppbv

Atlanta-N

Atlanta-F

Houston-N

Houston-F

Chicago-N

Chicago-F

339,542

Figure 4.3-2. Effect of fuel and mode on observed concentrations in the kitchen. The 

legend “N” is normal and “F” is malfunction. The 1,3-BD value for Houston-F is suspect. 

0

10

20

30

40

50

60

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

compound

Garage, ppbv

Atlanta-N

Atlanta-F

Houston-N

Houston-F

Chicago-N

Chicago-F

Figure 4.3-3. Effect of fuel and mode on observed sedan garage levels. The legend “N” is 

normal and “F” is malfunction. The 1,3-BD level for Houston-F is suspect. 
10

0

20

40

60

80

100

120

140

160

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO,ppm Formal EtOH Acetal

compound

Garage, ppbv

Atlanta-N

Atlanta-F

Houston-N

Houston-F

Chicago-N

Chicago-F

Figure 4.3-4. Effect of fuel and mode on observed truck garage levels. The legend “N” is 

normal and “F” is malfunction. The 1,3-BD level for Houston-F is suspect 

Section 5. Effect of Ventilation, Proximity, and Emission Levels on InCabin Exposures of Trailing Vehicle 

Table 5.3-1. Summary of Summer and Winter Background Concentrations. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal EtOH Acetal

Mean Summer (n=6) 0.02 0.27 0.44 0.07 0.17 0.11 0.06 0.13 5.80 261 2.80

% std dev 54% 26% 15% 24% 46% 48% 131% 18% 84% (n=1) 90%

Mean Winter (n=12) 0.03 0.32 0.52 0.11 0.38 0.16 0.08 0.21 5.62 22.07 4.05

% std dev 46% 46% 67% 61% 63% 62% 101% 38% 63% 88% 42%

Mean all 0.03 0.31 0.49 0.10 0.31 0.14 0.07 0.19 5.68 81.81 3.64

% std dev 50% 42% 58% 59% 72% 63% 107% 41% 68% 147% 56%

Budi13 = 1,3BD; Benze = benzene; Tolue = toluene, Mp_xyl = m,p-xylene; o_xyl = o-xylene, 

Formal = formaldehyde; EtOH = ethanol, Acetal = acetaldehyde 
11

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal/10 Acetal/10

Concentrations (ppbv or ppmv)

Mean Summer (n=6) Mean Winter (n=12)

Figure 5.3-1. Comparison of Summer and Winter Background Concentrations with 

Standard Deviations. Formaldehyde and acetaldehyde is divided by 10 for scale. 

Table 5.3-2. Summary of Test Concentrations for Summer, Winter and Overall. Units are 

ppbv, except CO as noted. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal EtOH

Mean Summer (n=12) 0.69 1.40 2.32 0.43 1.25 0.59 0.44 1.00 6.84 5.61 2308.07

% std dev 103% 69% 56% 65% 62% 63% 230% 72% 47% 71% 102%

Mean Winter (n=24) 0.59 1.20 1.99 0.37 1.30 0.50 0.83 1.72 4.82 2.54 1.70

% std dev 96% 76% 73% 77% 74% 76% 220% 91% 70% 75% 51%

Mean all 0.62 1.26 2.09 0.39 1.28 0.53 0.70 1.49 5.53 3.63 693.61

% std dev 100% 75% 67% 73% 70% 71% 233% 91% 63% 89% 250%

Budi13 = 1,3BD; Benze = benzene; Tolue = toluene, Mp_xyl = m,p-xylene; o_xyl = o-xylene, 

Formal = formaldehyde; EtOH = ethanol, Acetal = acetaldehyde 
12

0

1

2

3

4

5

6

7

8

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal

Concentrations (ppbv or ppmv)

Mean Summer (n=12) Mean Winter (n=24)

Figure 5.3-4. Comparison of Summer and Winter Concentrations for the Trailing tests. 

Table 5.3-3. Summary of Concentrations Observed During Idle Tests. Units are ppbv 

except CO as noted. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal EtOH Acetal

Mean Summer (n=11) 1.50 3.77 4.96 0.80 2.45 0.99 1.54 2.16 9.61 1030.68 9.04

% std dev 149% 116% 103% 110% 109% 104% 195% 160% 43% 59% 65%

Mean Winter (n=12) 0.66 2.57 3.01 0.48 1.71 0.65 0.54 3.06 6.53 3.86 3.37

% std dev 156% 137% 136% 111% 111% 96% 169% 118% 40% 61% 28%

Mean all 1.08 3.17 3.99 0.64 2.08 0.82 1.04 2.61 8.00 517.27 6.08

% std dev 163% 124% 116% 114% 110% 103% 214% 133% 46% 131% 81%

Table 5.3.4. Effect of Vehicle, Fuel, and Operational Mode. Units are ppbv, except CO as 

noted. Number of measurements = n 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal

Truck only (n=12) 0.64 1.40 2.32 0.45 1.46 0.61 0.87 1.56 4.55 3.67

Car only (n=12) 0.59 1.13 1.87 0.33 1.11 0.45 0.53 1.42 5.90 3.59

Atl fuel only (n=8) 0.53 1.44 2.79 0.51 1.66 0.68 0.14 1.41 5.99 3.39

Hou fuel only (n=8) 0.89 1.52 2.20 0.48 1.58 0.66 2.17 1.91 5.61 4.37

Chi fuel only (n=8) 0.48 0.87 1.32 0.20 0.66 0.28 0.03 1.22 4.20 3.19

Normal only (n=12) 0.06 0.46 1.05 0.21 0.73 0.31 0.16 0.41 5.21 3.26

High emitter only (n=12) 1.06 1.95 2.99 0.55 1.77 0.71 1.21 2.50 5.37 3.37

St Dev high emitter only 28% 36% 38% 41% 44% 44% 177% 52% 52% 64%
13

Table 5.3-5. Influence of high emitting vehicles and each fuel on trailing vehicle in-cabin 

concentrations. Units are ppbv except CO as noted 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal

High Emiter, Atl (n=4) 1.02 2.35 3.97 0.67 2.12 0.85 0.03 2.48 5.04 2.80

High Emiter, Hou (n=4) 1.43 2.18 3.08 0.69 2.24 0.93 3.45 2.81 6.00 5.77

High Emiter, Chi (n=4) 0.91 1.40 2.02 0.31 0.98 0.42 0.06 2.08 5.42 3.90

Table 5.3-6. Summary of Seasonal Differences in the High Emitter Samples. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal

Summer High 1.23 2.15 3.33 0.61 1.79 0.82 0.76 1.52 8.02 7.66

Winter High 1.06 1.89 2.86 0.53 1.78 0.69 1.39 2.92 4.22 2.27

Table 5.3-7. Comparison of High and Low In-cabin Ventilation Conditions, Winter 2005 

only. Units are ppbv except CO as noted. 

Budi13 Benze Tolue Etbz Mp_xyl O_xyl MTBE CO, ppm Formal Acetal

High Vent only 0.52 1.15 2.07 0.40 1.35 0.54 0.74 1.54 4.38 2.13

Low Vent only 0.64 1.24 1.91 0.35 1.25 0.47 0.91 1.89 4.65 3.08