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Ultrafine Particles and Freeways

Ultrafine Particles and Freeways. Yifang Zhu , Ph.D. Assistant Professor Department of Environmental Engineering Texas A&M University –Kingsville Email: yzhu@even.tamuk.edu yifang.zhu@tamuk.edu. Comparison of PM10, PM2.5, and Ultrafine PM. Ultrafine PM (0.1 m m). PM2.5 (2.5 m m).

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Ultrafine Particles and Freeways

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  1. Ultrafine Particles and Freeways Yifang Zhu , Ph.D. Assistant Professor Department of Environmental Engineering Texas A&M University –Kingsville Email: yzhu@even.tamuk.edu yifang.zhu@tamuk.edu

  2. Comparison of PM10, PM2.5, and Ultrafine PM Ultrafine PM (0.1 mm) PM2.5 (2.5 mm) PM10 (10 mm) PM2.5 (2.5 mm) PM10 (10 mm) Relative size of particles Human Hair (60 mm diameter)

  3. Number Distribution UltrafineParticles Mass Distribution PM2.5 PM10 Atmospheric Aerosols: Particulate Matter (PM) Size Distribution Source: Hinds 1999

  4. Particle Regional Deposition for Light Exercise Number Weighted Head Airways Alveolar Mass Weighted Tracheobronchial 1 10 100 1000 10000 Particle Diameter (nm)

  5. Translocation of UFP from NP and TB region along sensory neurons to CNS (neurodegeneration) • Translocation of UFP to • interstitium, capillaries, heart • Uptake by endothelium; platelets • Activation/interaction of endothelial • cells, platelets and leukocytes Alveolar inflammation Pathways of Particle Translocation Within and Outside Respiratory Tract

  6. Publications Address Ultrafine Particles

  7. I-405 Freeway

  8. Night Day Sampling Site

  9. Scanning Mobility Particle Sizer (SMPS): Particle Size Distribution (6-300 nm) Condensation Particle Counter (CPC): Total Particle Number Concentration Dust Trak: Real time PM10, PM2.5 Q-Trak: CO, CO2, Temp, Rh Portable Aethelometer: EC Weather Wizard III: Wind speed and direction INSTRUMENTS

  10. Experimental Setup: 2001 Daytime

  11. Traffic Effect: Total Particle Number Concentration & Traffic Density Zhu et al., 2002a

  12.  Normal Traffic  Traffic Slowdown Zhu et al., 2002a

  13. RESULTS:Change in Ultrafine Particle Size Distribution with Increasing Distance Day Zhu et al., 2002a

  14. RESULTS: Number Concentration for Different Size Ranges Vs. Increasing Distance from Freeway 405. Zhu et al., 2002a

  15. RESULTS: Relative Particle Number, Mass, Black Carbon, CO Concentration, Vs. Downwind Distance from Freeway 405. Zhu et al., 2002a

  16. Experimental Setup: 2004 Nighttime

  17. Nighttime Dominant Wind Nighttime Dominant Wind RESULTS:Decay of Total Particle Number Concentration Daily exposure to Ultrafine Particles: 3 folds of difference between the two cases

  18. Nighttime Dominant Wind Nighttime Dominant Wind RESULTS:Decay of Total Particle Number Concentration

  19. Y=5.17e3+1.17e5exp(-0.071X) R2=0.99 Y=7.35e4-1.74e3X R2=0.98 RESULTS:Temperature Effect Zhu et al, 2006

  20. Indoor Study  Sampling Site and Dominant Wind Zhu et al., 2005

  21. I-405 Freeway

  22. RESULTS: Effect of distance from freeways  Apartment 1  Apartment 2 Zhu et al., 2005

  23. RESULTS: Effect of Ventilation Conditions on Size Segregated I/O Ratios Zhu et al., 2005

  24. RESULTS: Effect of Ventilation Conditions on Size Segregated I/O Ratios Zhu et al., 2005

  25. RESULTS: Effect of Ventilation Conditions on Size Segregated I/O Ratios Zhu et al., 2005

  26. In-Cabin Study

  27. Outdoor and In-Cabin Size Distribution Time Series Zhu et al., 2007

  28. Average Outdoor UFP Distribution on Different Freeways Zhu et al., 2007

  29. Average In-Cabin UFP Distribution on Different Freeways Zhu et al., 2007

  30. Similar I/O Ratio Profiles on Different Freeways Zhu et al., 2007

  31. Effect of Ventilation Conditions on I/O Profiles Zhu et al., 2007

  32. TAKE HOME MESSAGES • Because of dilution (and coagulation/condensation) ultrafine particles behave like a local source. • Central station monitoring not useful for estimating dose • 1 hr on freeway exceeds 23 hrs away from freeway. • Newer vehicles with recirculation on helps to reduce in-cabin ultrafine particle exposure.

  33. TAKE HOME MESSAGES • Most ultrafine particles formed after exhaust leaves the tailpipe • Cooling and dilution both occurring • Cooling increases nucleation • Dilution decreases nucleation • Complex physical process • Sensitive to environmental conditions

  34. FUTURE WORD • Assessing Children’s Exposure to Ultrafine Particles from Vehicular Emissions • Objective: To identify hot spots in South Texas where school children are likely to be exposed to high levels of UFPs and develop simple models to estimate children’s exposure to UFPs from vehicular emissions. • Using In-Situ Observations to Quantify Emissions from Prescribed Fires in two Grassland-Pine Ecosystems • Objective: To directly quantify UFP emissions from prescribed fires on DoD managed grassland and grass-shrub type ecosystems with different fuel types and fuel loadings.

  35. FUTURE WORD Master and Ph.D. Students will be Financially Supported in Part by National Science Foundation (NSF) sponsored Center for Research Excellence in Science and Technology (CREST)- Research in Environmental Sustainability for Semiarid Coastal Areas (RESSACA) at Environmental Engineering Department at Texas A&M University-Kingsville.

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