1. 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 Workshop for Air Toxics and Health Effects October 17-18, 2005 University of Houston http://www.imaqs.uh.edu

2. Why modeling air toxics? To better understand their impacts on human health and air quality To better understand their impacts on human health and air quality To protect public health by limiting their emissions from man- made sources 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 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 ”

3. Linking Air Quality and Exposure Modeling 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 Ching, 2005 presentation

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

5. Key Issue: How to improve Air Toxics Emissions Inventories Air toxics Emissions Processing Method Air toxics Emissions Processing Method Separate processing: of toxics species that do not get involved in the main chemistry (i.e. CMAQ/HAPS) 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 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 Emissions Inventory? Which Model Species? Which Model Species? How to process?? How to process?? http://www.imaqs.uh.edu

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

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

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

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

10. Comparison with hourly observations at Clinton site

13. TEIb4a+NEI99 gives a better agreement between the simulation results and Clinton observational data for benzene Some success & some failures: But modeling advances are very promising if and only if we can improve emissions inventories… 2. TEI00 + NEI99:  TEIb4a + HAPs  TEIb4a + HAPs 3.NEI99 + TRI00:  CAPs + ( HAPs + TRI00)  CAPs + ( HAPs + TRI00) Comparison with observations at Clinton site

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

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

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

17. Mobile Source Air Toxics (MSAT) Compounds By default: Benzene, 1,3-Butadiene, Formaldehyde, Acetaldehyde, Acrolein, MTBE By default: Benzene, 1,3-Butadiene, Formaldehyde, Acetaldehyde, Acrolein, MTBE Extended: 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

18. Additional Parameters needed for Air Toxic Calculations GAS AROMATIC%: aromatic content of gasoline on a percentage of total volume basis 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 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 GAS BENZENE%: benzene content of gasoline on a percentage of total volume basis E200: Percentage of vapor a given gasoline produces at 200°F E200: Percentage of vapor a given gasoline produces at 200°F E300: percentage of vapor a given gasoline produces at 300°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 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

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

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

27. Example of Link-based Emissions BenzeneToluene XyleneStyrene

28. Benzene http://www.imaqs.uh.edu

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

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

31. Point source emissions inventory differences

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

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

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

35. Current Developments in Air Toxics Modeling at IMAQS, University of Houston An Extended Chemical Mechanism of the EPA’s CMAQ for Air Toxics Studies (Poster) 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; SAPRC99/extended (CMAQ/AT) 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 Suitable for studying acute health effects and verifying auto GC and canister measurements http://www.imaqs.uh.edu

36. Current Developments in Air Toxics Modeling at IMAQS, University of Houston A Transport Model for the Air Toxics Studies (Poster) 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 New method for air quality modeling -- under development An Eulerian-Lagrangian Hybrid Modeling Method, Trajectory Adaptive Grid (TAG) underdevelopment (CMAQ/TAG) 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 Can handle multiscale air quality issues at reasonable computational cost with high accuracy http://www.imaqs.uh.edu

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

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