DISCOVER-AQ Houston as a case study for understanding spatial and temporal trends in urban particulate matter

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1 DISCOVER-AQ Houston as a case study for understanding spatial and temporal trends in urban particulate matter Rebecca J. Sheesley and Sascha Usenko Department of Environmental Science, Baylor University, Waco, TX AQRP: Elena McDonald-Buller TCEQ: Shantha Daniel

2 Introduction PM concentrations can display large spatial and temporal heterogeneity across urban areas Distinct temporal and spatial regimes in urban PM are expected for Houston Variable time resolution sampling at four Houston sites during DISCOVER-AQ was designed to capture these regimes () AQRP 1-3

3 Research Goal The overall goal was to quantify the strength of PM formation and contributions of PM emission sources, including industrial sources, motor vehicle exhaust, biomass burning and biogenic emissions, across the Houston metropolitan area.

4 Objectives Utilize molecular marker-cmb modeling, enhanced with radiocarbon source apportionment, to tightly constrain fossil and contemporary sources including motor vehicle exhaust, biomass burning, and total biogenic contribution. Utilize semi-quantitative tracers to characterize secondary organic aerosol (SOA) (i.e WSOC), local urban emissions (persistent organic pollutants; POPs) and rural impacts (pesticides).

5 Carbon Source Apportionment Quantitative efforts include Radiocarbon 1 C measurements, a definitive split between fossil and contemporary carbon Chemical Mass Balance (CMB) model Organic and inorganic molecular and elemental markers hopanes, steranes, PAHs, alkanes, levoglucosan and elemental tracers, EC and OC

6 Baylor Ground-Based Sites DISCOVER-AQ Houston 13

7 Ground-based Sites Moody Tower Manvel Croix La Porte Conroe

8 Particulate Matter Samples Ground-based Sites Sampler Type Sampler Operator Sampler Provider Moody Tower HVTSP BU BU Moody Tower MV.5 * BU BU Moody Tower HV.5 BU EPA Moody Tower HVTSP BU UW Moody Tower Aethalometer BU BU Manvel Croix HVTSP BU BU Manvel Croix MV.5 BU BU Manvel Croix HV.5 BU EPA Manvel Croix PAX BU DMT Conroe HV.5 UT EPA La Porte HVTSP EPA UW * Dual sample train with quartz fiber and Teflon filters EPA denotes Environmental Protection Agency BU denotes Baylor University UW denotes University of Wisconsin-Madison UT denotes University of Texas -Austin DMT denotes Droplet Measurement Technologies

9 Particulate Matter Samples Site Filter Type Potential Analysis Total collected Moody Tower QFF OCEC, WSOC, 1 C, organic contaminants and molecular markers 17 Moody Tower Teflon Trace metals 5 Moody Tower Aluminum OCEC, WSOC, 1 C, elemental and single particle analysis 35 Moody Tower/ PUF Organic contaminants and molecular 9 Manvel Croix markers Manvel Croix QFF OCEC, WSOC, 1 C, organic contaminants and molecular markers 7 Conroe QFF OCEC, WSOC, 1 C, organic contaminants and molecular markers La Porte QFF OCEC, WSOC, 1 C, organic contaminants and molecular markers 5 5

10 Bulk carbon: Elemental Carbon and Organic Carbon Ambient Concentration ( g/m 3 ) EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Moody Tower HV.5 Day Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept EC/OC Ratio

11 Bulk carbon: Elemental Carbon and Organic Carbon Manvel Croix HV.5 Day Ambient Concentration ( g/m 3 ) EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 3 Sept EC/OC Ratio

12 Bulk carbon: Elemental Carbon and Organic Carbon Conroe TSP September -8, 13 Ambient Concentration ( g/m 3 ) 8 EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio EC/OC Ratio Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept.

13 Bulk carbon: Elemental Carbon and Organic Carbon La Porte TSP September -8, Ambient Concentration ( g/m 3 ) EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio EC/OC Ratio Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept.

14 Ambient Concentration ( g/m 3 ) Ambient Concentration ( g/m 3 ) Elemental Carbon and Organic Carbon Sept EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Sept Sept 1 Sept 1 Sept 1 EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Moody Tower HV.5 Day Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept Conroe TSP September -8, 13 Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Sept Sept Sept 1 Sept 1 EC Conc. ( g/m 3 ) EC/OC Ratio EC/OC Ratio Manvel Croix HV.5 Day Sept 1 Sept 1 Sept 1 Sept Sept 3 Sept La Porte TSP September -8, 13 Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept EC/OC Ratio EC/OC Ratio..

15 Bulk carbon: Water-soluble organic carbon Moody Tower HV.5 Day 8 1. Ambient Concentration ( g/m 3 ) Sept WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept WSOC/OC Ratio

16 Bulk carbon: Water-soluble organic carbon Manvel Croix HV.5 Day 1. Ambient Concentration ( g/m 3 ) Sept WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept WSOC/OC Ratio

17 Bulk carbon: Water-soluble organic carbon Conroe HV.5 Day 8 1. Ambient Concentration ( g/m 3 ) Sept WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept WSOC/OC Ratio

18 Bulk carbon: Water-soluble organic carbon La Porte TSP 1 1. Ambient Concentration ( g/m 3 ) WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept WSOC/OC Ratio

19 Water-soluble organic carbon 8 Moody Tower HV.5 Day 1. Manvel Croix HV.5 Day 1. Ambient Concentration ( g/m 3 ) Ambient Concentration ( g/m 3 ) 8 Sept Sept WS WSOC/OC Ratio WSOC/OC Ratio WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept 1 Sept 1 Sept 1 Sept 1 Conroe HV.5 Day Sept Sept 1 Sept Sept 3 Sept Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept Sept WS WSOC/OC Ratio WSOC/OC Ratio WS WSOC/OC Ratio WSOC/OC Ratio Sept Sept 1 Sept 1 Sept 1 Sept 1 La Porte TSP Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept Sept Sept 1 Sept Sept 3 Sept Sept WSOC/OC Ratio WSOC/OC Ratio

20 PM.5 speciation at Moody Tower Moody Tower HV PM.5 1 Ambient Concentration ( g/m 3 ) Sept _M Sept _A Sept _N _M _D _D Sept 1_D _D Sept 1_D _D Sept 1_D _D Sept 1_D _M _A _D _M _A Sept _D Sept 1_D Sept _D Sept 3_D Sept _D _D Sept _D _D _D EC ( g/m 3 ) OC * 1. ( g/m 3 ) Chloride ( g/m 3 ) Nitrate ( g/m 3 ) Sulfate ( g/m 3 ) Ammonium ( g/m 3 ) Soluble Sodium ( g/m 3 ) Soluble Potassium ( g/m 3 )

21 PM.5 speciation at Conroe Inorganic Conroe HV PM.5 Ambient Concentration ( g/m 3 ) 1 EC ( g/m 3 ) OC * 1. ( g/m 3 ) Sept Sept Sept 1 Sept 1 Sept 1 Sept 1 Sept Sept 1 Sept Sept 3 Sept Sept Chloride ( g/m 3 ) Nitrate ( g/m 3 ) Sulfate ( g/m 3 ) Ammonium ( g/m 3 ) Soluble Sodium ( g/m 3 ) Soluble Potassium ( g/m 3 ) Conroe PM.5 TEOM

22 Ambient concentration g m Chemical Mass Balance Modeling TSP PM.5 Vegetative Detritus Woodsmoke Motor Vehicle Exhaust Unapportioned OC Sept, La Porte Sept 1, La Porte Sept, La Porte Sept 3, La Porte Sept, La Porte, La Porte Sept, La Porte Sept 1, Moody Tower Sept, Moody Tower Sept 3, Moody Tower Sept, Moody Tower, Moody Tower Sept, Moody Tower Sept 1, Manvel Croix Sept, Manvel Croix Sept 3, Manvel Croix Sept 1, Conroe Sept, Conroe Sept 3, Conroe

23 Organophosphate Ester (PM-TSP) Flame Retardants and Plasticizers Ambient Concentrations (pg/m 3 ) TCEP TCPP TDCPP TPP TBEP TEHP EHDP TBP Ambient Concentration (pg/m 3 ) MC AVG MT AVG CHICAGO AVG Manvel Croix Moody Tower Chicago TBP TCEP TCPP TDCPP TPP TBEP TEHP There are few studies of OPEs. Moody Tower has a similar profile to other urban source regions. Manvel Croix shows a similar profile to remote sites. This data suggests significant processing over the urban gradient.

24 Current-Use Pesticides (PM TSP) Permethrin and malathion are applied mosquito adulticides with known county application programs (location and time). They are easily measured in Houston PM.5 at all sites. The application and measurement presents an unique opportunity for the investigation of atmospheric transport and oxidation pathways in Houston.

25 Radiocarbon Data 1. Fraction Contempoary Carbon PM.5 el Croix Sept 1_D anvel Croix Sept _D Manvel Croix Sept 3_D Manvel Croix _D Manvel Croix Sept _D Manvel Croix _D Manvel Croix _D Conroe Sept 1 Conroe Sept Conroe Sept 3 Conroe Sept Conroe Conroe Sept Conroe Conroe Moody Tower Sept 1_D Moody Tower Sept _D Moody Tower Sept 3_D Moody Tower Sept _D Moody Tower _D Moody Tower Sept _D Moody Tower _D Moody Tower _D Moody Tower Sept 3_D TSP Moody Tower Sept 3_N Moody Tower Sept _D Moody Tower Sept _N Moody Tower _D Moody Tower _N La Porte Sept 1 La Porte Sept La Porte Sept 3 La Porte Sept La Porte La Porte Sept

26 Moody Tower: Contemporary OC Primary contemporary OC Contemporary TOC Ambient concentration ( g m -3 ) 3 1 PM.5 Moody Tower Sept 1_D Moody Tower Sept _D Moody Tower Sept 3_D Moody Tower Sept _D Moody Tower _D Moody Tower Sept _D

27 Moody Tower: Fossil OC Motor vehicle exhaust OC Fossil TOC Ambient concentration ( g m -3 ) PM.5 Moody Tower Sept 1_D Moody Tower Sept _D Moody Tower Sept 3_D Moody Tower Sept _D Moody Tower _D Moody Tower Sept _D

28 Future questions Investigate sources of semi-volatile OC using radiocarbon Extend detailed source analysis during DISCOVER-AQ high ship emission events in Houston Early Sept, high primary pollution regime Examine processing of particle phase organics with ozone Potential impacts during peak ozone, NOx events Seasonal variability of primary vs secondary organic aerosol Radiocarbon and organic tracers Mobile Sampling Trailer: outfitted with PM (TSP and.5) NOx, Ozone, Aethalometer, and PTR-MS (VOCs)

29 Acknowledgements Funding Texas AQRP University of Houston Site Access and Site Modification TCEQ Site Access and Site Modification USEPA Samplers University of Wisconsin-Madison Samplers Droplet Measurement Technologies USEPA Filter Collection University of Texas, Austin Filter Collection