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PSU Friday Transportation
Seminar
13 February, 2015
Transportation System Impacts
on Bicyclists' Air Pollution Risks
Alex ...
Framework
2
Vehicle
Emissions
Air
Quality
Traveler
Exposure
Inhalation
Uptake
Health
Effects
Bicyclists' Pollution Uptake
Background
3Bicyclists' Pollution Uptake
Bicyclists’ Exposures
4
0 5 10 15 20
Ultrafine PM
Fine PM
Coarse PM
Black Carbon
CO
VOC
NO2
# studies measuring on-road
bi...
Modal Comparisons of Exposure
– Is this actionable information?
Context-dependent results
– Bicyclists lower if separated
...
High-Traffic/Low-Traffic Routes
6Bicyclists' Pollution Uptake
-50%
0%
50%
100%
150%
200%
250%
CO VOC UFP PM2.5 PM10 BC
Exp...
Ventilation and Exercise
7Bicyclists' Pollution Uptake
50 100 150 200 250
Watts
Ventilation(liter/min)
75
50
25
Ventilation & Bicycle Studies
8
57 studies assess
bicyclists’ exposure
Ignored
38
Constant
16
Assumed/
Modeled
15
Measured...
Bicyclist Uptake Studies
2 studies of biomarkers:
• VOC: blood & urine
– Urban bikers > rural bikers
• BC: induced sputum
...
Research Questions
1. How does uptake vary with
roadway and travel
conditions?
2. Can transport strategies
reduce bicyclis...
Data & Methods
11Bicyclists' Pollution Uptake
Breath Biomarkers
Exhaled breath is a good proxy for
blood concentrations of VOC
12Bicyclists' Pollution Uptake
alphaszens...
Sampling Equipment
13Bicyclists' Pollution Uptake
1) Local roads Pre
Breath
Post
Breath
On-Road Sampling Segments
20-30 minutes, 3-5 miles
Exposure & breath VOC
Paired subj...
Exposure Data coverage
15Bicyclists' Pollution Uptake
74 breath
samples
3 subjects
9 days
~40 hours
of data
Model Development
• Exposure concentrations
• Ventilation
• Breath concentrations
~ exposure + ventilation
~ weather + roa...
Results
17Bicyclists' Pollution Uptake
Results: VOC Exposure Models
• +2% per 1,000 ADT
• +20-30% in stop-and-go riding
• Off-street path +300% in industrial
cor...
19
Industrial Corridor
Bicyclists' Pollution Uptake
20
Parallel Path Comparison
Bicyclists' Pollution Uptake
E Burnside St. SE Ankeney St.
N Williams Ave. NE Rodney Ave.
Nait...
Results: Ventilation Models
• 4-8% increase in
ventilation per 10 W
• Mean lag
~50 sec
21Bicyclists' Pollution Uptake
0 50...
Breath and Exposure Concentrations
0 1 2 3
Breath
Exposure
Concentration (normalized to Park)
Toluene
Major arterials
Loca...
Results: Breath Biomarkers
• 8 aromatic hydrocarbons were
biomarkers of traffic exposure
• Issues
– Background concentrati...
Explained variance in breath BTEX
24Bicyclists' Pollution Uptake
0%
10%
20%
30%
40%
50%
Measured variables Modeled variabl...
Applications
25Bicyclists' Pollution Uptake
Steady-state biking work
26Bicyclists' Pollution Uptake
0
50
100
150
200
250
0 2 3 5 6 8 9 11 13 14 16
Workload(W)
Speed (...
Inhalation and Speed
27Bicyclists' Pollution Uptake
0
50
100
150
200
250
300
0 4 8 12 16
Ventilation(l/km)
Speed (mph)
0% ...
Minimum-Inhalation Speed
28Bicyclists' Pollution Uptake
0
5
10
15
0% 2% 4% 6% 8% 10%
Minimum-ventilation
speed(mph)
Grade
Inhalation and Stops
29Urban Bicyclists' Pollution Uptake
0
100
200
300
400
500
600
6 8 10 12 14 16 18
Cruise-equivalentex...
Route Choice
• Detour 1 block to a bikeway vs.
– 1.6 blocks on a major arterial
– 4.3 blocks on a minor arterial
30Bicycli...
Comparison with Preferences
31Bicyclists' Pollution Uptake
Will bicyclists naturally minimize
inhaled dose over a trip?
Bi...
Exercise and Uptake
• Inhalation rate: 2-5x higher
• PM uptake: ≥2-5x higher
• VOC uptake: 1.5-2x higher
– Limited by bloo...
Conclusions
33Bicyclists' Pollution Uptake
Findings
Determining
factors
• ADT
• Stop-and-go riding
• Industrial
corridors
• Speed & grade
• Exposure &
ventilation
Mi...
Take-Away Principles
1. Bicyclist Exposure
a) Many different pollutants
b) Traffic, weather, and land-use all important
c)...
Bikeway Design Considerations
Bike lane • High-traffic streets
• Some lateral separation
• Dedicated lane reduces duration...
Next Steps
• Abstraction for HIA & CBA
• Additional biomarkers
• Characterizations of urban bicyclists
• Similar study for...
Crowd-Sourced Pollution Data
38Urban Bicyclists' Pollution Uptake
Questions?
abigazzi@pdx.edu
alexbigazzi.com
39Bicyclists' Pollution Uptake
Acknowledgments
• Dissertation committee: Migue...
Bonus Slides!
40Bicyclists' Pollution Uptake
ADT
41Bicyclists' Pollution Uptake
Parallel Paths
• Burnside > Ankeny
– 51% TVOC, 201% CO, 9% PM2.5
• Williams > Rodney
– 329% TVOC, 221% CO
• Naito > McCall...
Explained Variance
43Urban Bicyclists' Pollution Uptake
0%
10%
20%
30%
40%
50%
60%
BTEX Exposure Exposure variability Vent...
Inhalation and Grade
44Bicyclists' Pollution Uptake
0
50
100
150
200
250
300
-2% -1% 0% 1% 2% 3% 4% 5%
Ventilation(l/km)
G...
Minimum-ventilation envelope
45Urban Bicyclists' Pollution Uptake
0
5
10
15
20
25
30
0% 2% 4% 6% 8% 10%
Min-ventilationven...
Results: Uptake Models
• Elasticity of breath to exposure ~0.5
– Δ Breath ~ ½ Δ Exposure
– No significant difference by su...
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Transportation System Impacts on Bicyclists' Air Pollution Risks: Considerations for System Design and Use

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Alex Bigazzi, Ph.D., Portland State University

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Transportation System Impacts on Bicyclists' Air Pollution Risks: Considerations for System Design and Use

  1. 1. PSU Friday Transportation Seminar 13 February, 2015 Transportation System Impacts on Bicyclists' Air Pollution Risks Alex Bigazzi Miguel Figliozzi James Pankow Wentai Luo Considerations for System Design and Use
  2. 2. Framework 2 Vehicle Emissions Air Quality Traveler Exposure Inhalation Uptake Health Effects Bicyclists' Pollution Uptake
  3. 3. Background 3Bicyclists' Pollution Uptake
  4. 4. Bicyclists’ Exposures 4 0 5 10 15 20 Ultrafine PM Fine PM Coarse PM Black Carbon CO VOC NO2 # studies measuring on-road bicyclists’ exposure concentrations Pollutant 42 studies Bicyclists' Pollution Uptake
  5. 5. Modal Comparisons of Exposure – Is this actionable information? Context-dependent results – Bicyclists lower if separated 5Bicyclists' Pollution Uptake vsvs
  6. 6. High-Traffic/Low-Traffic Routes 6Bicyclists' Pollution Uptake -50% 0% 50% 100% 150% 200% 250% CO VOC UFP PM2.5 PM10 BC ExposureIncreaseon High-TrafficRoutes N=6 N=11 N=8 N=6 N=3 N=5
  7. 7. Ventilation and Exercise 7Bicyclists' Pollution Uptake 50 100 150 200 250 Watts Ventilation(liter/min) 75 50 25
  8. 8. Ventilation & Bicycle Studies 8 57 studies assess bicyclists’ exposure Ignored 38 Constant 16 Assumed/ Modeled 15 Measured 1 Variable 3 Modeled 2 Measured 1 Ventilation: Urban Bicyclists' Pollution Uptake
  9. 9. Bicyclist Uptake Studies 2 studies of biomarkers: • VOC: blood & urine – Urban bikers > rural bikers • BC: induced sputum – Bicyclists > transit riders 9Bicyclists' Pollution Uptake
  10. 10. Research Questions 1. How does uptake vary with roadway and travel conditions? 2. Can transport strategies reduce bicyclist uptake? 10Bicyclists' Pollution Uptake
  11. 11. Data & Methods 11Bicyclists' Pollution Uptake
  12. 12. Breath Biomarkers Exhaled breath is a good proxy for blood concentrations of VOC 12Bicyclists' Pollution Uptake alphaszenszor.com VOC in blood
  13. 13. Sampling Equipment 13Bicyclists' Pollution Uptake
  14. 14. 1) Local roads Pre Breath Post Breath On-Road Sampling Segments 20-30 minutes, 3-5 miles Exposure & breath VOC Paired subjects 14Bicyclists' Pollution Uptake Pre Breath Post Breath 2) Major arterials
  15. 15. Exposure Data coverage 15Bicyclists' Pollution Uptake 74 breath samples 3 subjects 9 days ~40 hours of data
  16. 16. Model Development • Exposure concentrations • Ventilation • Breath concentrations ~ exposure + ventilation ~ weather + roadway + travel conditions 16Bicyclists' Pollution Uptake
  17. 17. Results 17Bicyclists' Pollution Uptake
  18. 18. Results: VOC Exposure Models • +2% per 1,000 ADT • +20-30% in stop-and-go riding • Off-street path +300% in industrial corridor 18Bicyclists' Pollution Uptake
  19. 19. 19 Industrial Corridor Bicyclists' Pollution Uptake
  20. 20. 20 Parallel Path Comparison Bicyclists' Pollution Uptake E Burnside St. SE Ankeney St. N Williams Ave. NE Rodney Ave. Naito Pkwy. Riverside Path
  21. 21. Results: Ventilation Models • 4-8% increase in ventilation per 10 W • Mean lag ~50 sec 21Bicyclists' Pollution Uptake 0 50 100 150 0.0 0.2 0.4 0.6 0.8 Seconds workload lagged Cumulativeimpactonventilation(% Subjec A B C Pooled %ΔventilationperW Seconds lag
  22. 22. Breath and Exposure Concentrations 0 1 2 3 Breath Exposure Concentration (normalized to Park) Toluene Major arterials Local roads 22Bicyclists' Pollution Uptake
  23. 23. Results: Breath Biomarkers • 8 aromatic hydrocarbons were biomarkers of traffic exposure • Issues – Background concentrations – Endogenous production – High water solubility 23Bicyclists' Pollution Uptake
  24. 24. Explained variance in breath BTEX 24Bicyclists' Pollution Uptake 0% 10% 20% 30% 40% 50% Measured variables Modeled variables Exposure Ventilation Exposure variability Weather variables Road & traffic variables
  25. 25. Applications 25Bicyclists' Pollution Uptake
  26. 26. Steady-state biking work 26Bicyclists' Pollution Uptake 0 50 100 150 200 250 0 2 3 5 6 8 9 11 13 14 16 Workload(W) Speed (mph) Rolling Resistance Drag 1% Grade
  27. 27. Inhalation and Speed 27Bicyclists' Pollution Uptake 0 50 100 150 200 250 300 0 4 8 12 16 Ventilation(l/km) Speed (mph) 0% Grade 2% Grade
  28. 28. Minimum-Inhalation Speed 28Bicyclists' Pollution Uptake 0 5 10 15 0% 2% 4% 6% 8% 10% Minimum-ventilation speed(mph) Grade
  29. 29. Inhalation and Stops 29Urban Bicyclists' Pollution Uptake 0 100 200 300 400 500 600 6 8 10 12 14 16 18 Cruise-equivalentexcess ventilation(ft) Cruise speed (mph)
  30. 30. Route Choice • Detour 1 block to a bikeway vs. – 1.6 blocks on a major arterial – 4.3 blocks on a minor arterial 30Bicyclists' Pollution Uptake ?
  31. 31. Comparison with Preferences 31Bicyclists' Pollution Uptake Will bicyclists naturally minimize inhaled dose over a trip? Bike boulevard or neighborhood greenway Bike lane Minor arterial (no bike lane) Major arterial (no bike lane) • Slightly over-avoid • Balance on collectors (6-10k ADT) • Under-avoid arterials • Greatly over-avoid vs. vs. vs.
  32. 32. Exercise and Uptake • Inhalation rate: 2-5x higher • PM uptake: ≥2-5x higher • VOC uptake: 1.5-2x higher – Limited by blood/air equilibrium 32Bicyclists' Pollution Uptake
  33. 33. Conclusions 33Bicyclists' Pollution Uptake
  34. 34. Findings Determining factors • ADT • Stop-and-go riding • Industrial corridors • Speed & grade • Exposure & ventilation Mitigation • Low-volume streets • Travel speed choice • Reducing stops • Separated facilities 34Urban Bicyclists' Pollution Uptake
  35. 35. Take-Away Principles 1. Bicyclist Exposure a) Many different pollutants b) Traffic, weather, and land-use all important c) Benefits of separation from traffic 2. Bicyclist Inhalation a) Varies greatly with workload (speed, grade) b) Breath response spread out over 1-2 min 3. Bicyclist Uptake a) For particles, highly sensitive to breathing b) For some gases, more sensitive to duration 35Bicyclists' Pollution Uptake
  36. 36. Bikeway Design Considerations Bike lane • High-traffic streets • Some lateral separation • Dedicated lane reduces duration in congestion Bike boulevard • Low-traffic streets • Additional benefits from traffic calming • Fewer stops reduces uptake Cycle track • Lateral separation • Fewer stops reduces uptake Off-street path • Low exposure (nearby industry?) • Fewer stops reduces uptake 36Bicyclists' Pollution Uptake
  37. 37. Next Steps • Abstraction for HIA & CBA • Additional biomarkers • Characterizations of urban bicyclists • Similar study for pedestrians • Crowd-source pollution data 37Bicyclists' Pollution Uptake
  38. 38. Crowd-Sourced Pollution Data 38Urban Bicyclists' Pollution Uptake
  39. 39. Questions? abigazzi@pdx.edu alexbigazzi.com 39Bicyclists' Pollution Uptake Acknowledgments • Dissertation committee: Miguel Figliozzi, Jim Pankow, Robert Bertini, Jennifer Dill • NITC research project with support from City of Portland and Metro • NSF and OTREC fellowships
  40. 40. Bonus Slides! 40Bicyclists' Pollution Uptake
  41. 41. ADT 41Bicyclists' Pollution Uptake
  42. 42. Parallel Paths • Burnside > Ankeny – 51% TVOC, 201% CO, 9% PM2.5 • Williams > Rodney – 329% TVOC, 221% CO • Naito > McCall path – 112% TVOC, 30% CO, 4% PM2.5 42Bicyclists' Pollution Uptake
  43. 43. Explained Variance 43Urban Bicyclists' Pollution Uptake 0% 10% 20% 30% 40% 50% 60% BTEX Exposure Exposure variability Ventilation Road & traffic variables Weather variables
  44. 44. Inhalation and Grade 44Bicyclists' Pollution Uptake 0 50 100 150 200 250 300 -2% -1% 0% 1% 2% 3% 4% 5% Ventilation(l/km) Grade 11 kph 18 kph
  45. 45. Minimum-ventilation envelope 45Urban Bicyclists' Pollution Uptake 0 5 10 15 20 25 30 0% 2% 4% 6% 8% 10% Min-ventilationventilation (lpm) Grade
  46. 46. Results: Uptake Models • Elasticity of breath to exposure ~0.5 – Δ Breath ~ ½ Δ Exposure – No significant difference by subject • Ventilation effect small but significant for some compounds – Elasticity of 0.1-0.2 46Bicyclists' Pollution Uptake

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