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Prof. Daewon W. Byun Dr. Soontae Kim, Ms. Violeta Coarfa Dr. Peter Percell University of Houston

Workshop for Air Toxics and Health Effects October 17-18, 2005 University of Houston. Recent Developments in Air Quality Modeling Techniques for studying Air Toxics in the Houston-Galveston Area. Prof. Daewon W. Byun Dr. Soontae Kim, Ms. Violeta Coarfa Dr. Peter Percell

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Prof. Daewon W. Byun Dr. Soontae Kim, Ms. Violeta Coarfa Dr. Peter Percell University of Houston

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  1. Workshop for Air Toxics and Health Effects October 17-18, 2005 University of Houston Recent Developments in Air Quality Modeling Techniques for studying Air Toxics in the Houston-Galveston Area Prof. Daewon W. Byun Dr. Soontae Kim, Ms. Violeta Coarfa Dr. Peter Percell University of Houston Institute for Multidimensional Air Quality Studies Dr Graciela Lubertino, Houston Galveston Area Council Jason Ching, U.S. EPA http://www.imaqs.uh.edu

  2. To better understand their impacts on human health and air quality To protect public health by limiting their emissions from man-made sources To help communities prepare to better respond in case of chemical spills of such substances Air toxics assessment activities include - assessment of emissions: monitoring and modeling of air quality - programs for reducing exposure and emissions of pollutants; - development and implementation of control strategies of emissions; - emergency response in case of serious events. Fate-Transport Modeling Based on First Principles” Why modeling air toxics?

  3. Estimate emissions Obtain concentrations of chemical in the medium at distance of interest Determine exposure of the population of interest Calculate the risk of injury associated with that exposure Linking Air Quality and Exposure Modeling Ching, 2005 presentation

  4. Air toxics modeling Follows Ozone & PM approach US Continent Meteorology Where we are now…. Regional/State Air Quality HG area What we need to work on… Neighborhood scale For neighborhood scale modeling: Method 1: Combine CMAQ with ASPEN (following EPA’s Philadelphia Study) Method 2: Apply trajectory adaptive grid (TAG) method HAPEM Ching, 2005 presentation

  5. Air toxics Emissions Processing Method Separate processing: of toxics species that do not get involved in the main chemistry (i.e. CMAQ/HAPS) Combined processing of toxics with other photochemical (O3) and PM model species with full interaction (i.e. extended SAPRC) CMAQ/Air-Toxics Which Emissions Inventory? Which Model Species? How to process?? Key Issue: How to improve Air Toxics Emissions Inventories http://www.imaqs.uh.edu

  6. NEI Criteria VOC emissions Needs proper speciation profiles NEI HAP emissions One-to-one mapping Texas Criteria VOC emissions Needs proper speciation profiles Texas PSDB Speciated: One-to-one mapping MOBILE6.2 Toxic emissions from HGAC Toxic Emissions Inventories EPA air toxics Inventories available What we did What we are working on now Additional Efforts Required

  7. Preliminary studies have been done using three different inventories Emissions Data 1. EPA’s National Emissions Inventory NEI99 : Criteria (CAPs) + Hazardous (HAPs) Tools: SMOKE ; CMAQ/Air-Toxics ; PAVE Domain: 4km_83x65 Period: Aug, 22 – Aug, 31, 2000 Simulation results were compared with the observations Preliminary CMAQ/AT Results

  8. Emissions for toluene and ethylbenzene On-road Point Area Non-road Non-road Point Area On-road Air Toxics Emissions NEI99 with SMOKE2.1 Result August 25, 2000 18:00 CDT All Sources All Sources

  9. CMAQ/AT 4.4 results for aromatics August 25, 2000 08:00 CDT August 25, 2000 16:00 CDT Air Concentrations August 25, 2000 @ 1 pm GMT and 9 pm GMT

  10. Comparison with hourly observations at Clinton site

  11. Comparison with hourly observations at Clinton site

  12. Comparison with hourly observations at Clinton site

  13. Comparison with observations at Clinton site Some success & some failures: But modeling advances are very promising if and only if we can improve emissions inventories… • 2. TEI00 + NEI99: •  TEIb4a + HAPs • NEI99 + TRI00: •  CAPs + ( HAPs + TRI00) TEIb4a+NEI99 gives a better agreement between the simulation results and Clinton observational data for benzene

  14. NEI MOBILE MOBILE6 County-based Link-based Estimation Use surrogates Defined by location Spatial allocation Use x-ref & profiles Hourly emissions Temporal allocation HAPs MSATs Species What we are working on now  Link-based MOBILE 6.2 emissions Example species: BENZ, MTBE, BUTA, FORM, ACETA, ACROL, NAPTHALENE, ETHYLBENZE, N-HEXENE, STYRENE, TOLUENE, XYLENE, LEAD MSATS = mobile source air toxics species

  15. VMT factors, Capacity factors, Speed model parameters VMT mix TRANSVMT Transportation Network Data Set IMPSUM Hourly emissions Mobile6 input POLFAC RATEADJ How mobile emissions are estimated?

  16. Registration distribution- TTI Gasoline content – TCEQ Control programs – TCEQ Trip data – H-GAC Temperature, humidity – SIP Diesel sales fractions – TTI Calendar year Emission factors (g/mile) for different air chemical species MOBILE6: Input/Ouput INPUT OUTPUT

  17. By default: Benzene, 1,3-Butadiene, Formaldehyde, Acetaldehyde, Acrolein, MTBE Extended: Arsenic compounds, Chromium compounds, Dioxin/Furans, Ethylbenzene, n-Hexane, Lead compounds, Manganese compounds, Mercury compounds, Naphthalene, Nickel compounds, Polycyclic Organic Matter, Styrene, Toluene, Xylene, Diesel, Particulate Matter Mobile Source Air Toxics (MSAT) Compounds

  18. GAS AROMATIC%: aromatic content of gasoline on a percentage of total volume basis GAS OLEFIN%: olefin content of gasoline on a percentage of total volume basis GAS BENZENE%: benzene content of gasoline on a percentage of total volume basis E200: Percentage of vapor a given gasoline produces at 200°F E300: percentage of vapor a given gasoline produces at 300°F OXYGENATE: oxygenate type and content of gasoline on a percentage of total volume basis. There are four oxygenate types in the model: MTBE, ETBE, ETOH, TAME Additional Parameters needed for Air Toxic Calculations

  19. Houston Road Network What are required to estimate mobile source air toxics emissions?

  20. Road Network, Nodes & Links

  21. Processing is not always easy – the link data can be messed up

  22. Link Nodes inside HGB 8 Counties

  23. Link Nodes inside Harris County

  24. Example of MOBILE6 outputs

  25. Anode Bnode Roadtype Pollutant EmissionType grams emissions by vehicle type 1653 10893 8 BENZ COMPOSITE 1.1234693 1.3399E-1 1653 10893 8 BENZ EXH_RUNNING 2.8073E-1 3.7492E-2 1653 10893 8 BENZ START 7.1150E-1 8.3485E-2 1653 10893 8 BENZ HOT_SOAK 3.3991E-2 3.0365E-3 1653 10893 8 BENZ REST_LOSS 8.5768E-2 8.8688E-3 1653 10893 8 BENZ RUN_LOSS 1.1484E-2 1.1099E-3 1653 10893 8 MTBE COMPOSITE 3.4736070 3.6643E-1 1653 10893 8 MTBE EXH_RUNNING 1.3982E-1 2.0251E-2 1653 10893 8 MTBE START 4.3882E-1 5.9574E-2 1653 10893 8 MTBE HOT_SOAK 8.3029E-1 7.4172E-2 1653 10893 8 MTBE REST_LOSS 1.9068174 1.9717E-1 1653 10893 8 MTBE RUN_LOSS 1.5786E-1 1.5257E-2 1653 10893 8 BUTA COMPOSITE 1.5084E-1 1.7860E-2 1653 10893 8 BUTA EXH_RUNNING 4.1085E-2 5.1978E-3 1653 10893 8 BUTA START 1.0976E-1 1.2663E-2 1653 10893 8 FORM COMPOSITE 4.3185E-1 6.3634E-2 Example Output File

  26. Example of Link-based Emissions • VOC emissions from Brazoria County

  27. Example of Link-based Emissions Benzene Toluene Xylene Styrene

  28. Example of Link-based Emissions Benzene http://www.imaqs.uh.edu

  29. Further Processing of air toxics emissions with SMOKE for CMAQ/AT modeling EI Processing for AQMs Input data Link-to-gridded emissions Temporal profiles Allocating each link emissions to the covering cells Link-based MOBILE6 output Gridded MOBILE6 emissions SMOKE Hourly emissions Preparing MOBILE6 emission / vehicle types for temporal allocation Diurnal temporal x-ref and profile http://www.imaqs.uh.edu

  30. Static Adaptive Fine-mesh Eulerian (SAFE) Grid Point Source VOC Emissions inHouston-Galeston

  31. Point source emissions inventory differences

  32. Differences in Benzene Emissions from Point Sources TCEQ PSDB 2000 NEI99 HAP

  33. Differences in 1,3-Butadiene emissions from Point Sources TCEQ PSDB 2000 NEI99 HAP

  34. SAPRC99 0005 TOG ALK1 0.00083139342 1 0.025 0005 TOG ALK2 0.00030721966 1 0.008 0005 TOG ARO1 0.00007297401 1 0.01 0005 TOG CH4 0.05162094763 1 0.828 0005 TOG ETHENE0.00417112299 1 0.117 0005 TOG OLE1 0.00007129278 1 0.003 SAPRC Extended 0005 TOG CH4 0.90174382925 17.4718304 0.8280000 0005 TOG ALK1 0.01452596486 17.4718304 0.0250000 0005 TOG ALK2 0.00536810188 17.4718304 0.0080000 0005 TOG ETHE 0.07286676019 17.4718304 0.1170000 0005 TOG OLE1 0.00124558562 17.4718304 0.0030000 0005 TOG BENZ 0.00424974738 17.4718304 0.0190000 Processing of EI for speciated air toxics modeling requires speciation profile CMAQ/AT with Extended Aromatic Chemistry Mechanism

  35. An Extended Chemical Mechanism of the EPA’s CMAQ for Air Toxics Studies (Poster) Problem of popular chemical mechanisms: many chemical species are lumped; cannot simulated the behavior of individual compounds important in the atmospheric chemical processes and/or with serious impact on the human health and surroundings; Solution: find methods to implement species of interest in the chemical mechanisms employed by the photochemical models - SAPRC99/extended (CMAQ/AT) Suitable for studying acute health effects and verifying auto GC and canister measurements Current Developments in Air Toxics Modelingat IMAQS, University of Houston http://www.imaqs.uh.edu

  36. A Transport Model for the Air Toxics Studies (Poster) Long-term simulations (several months, yearly) are preferred to better analyze and understand the physical and chemical behavior of toxic pollutants Health effect studies need long-term simulations for a proper correlation between pollutant concentration and various health conditions; need a faster model than CMAQ/Air-Toxics; IMAQS developed an engineering version of CMAQ/Air-Toxics, which can simulates seasonal and annual simulations (CMAQ/HAPS)  Suitable for studying chronic health effects of air toxics New method for air quality modeling -- under development An Eulerian-Lagrangian Hybrid Modeling Method, Trajectory Adaptive Grid (TAG) underdevelopment (CMAQ/TAG) Can handle multiscale air quality issues at reasonable computational cost with high accuracy Current Developments in Air Toxics Modelingat IMAQS, University of Houston http://www.imaqs.uh.edu

  37. Trajectory Adaptive Grid (TAG) Algorithm(very, very preliminary results as of today) Lagrangian packets to represent movement of pollutants, but in Eulerian adative grid Eulerian Grid Eulerian Grid 2-D 3-D Lagrangian packets

  38. Testing of TAG – O3 (UTC 20:00 Aug 25) TAG-Result Preliminary O3 simulation results Maximum Packet Average Eulerian (CMAQ-PPM) Closest Minimum

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