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Air Toxics in Allegheny County: Sources, Airborne Concentrations, and Human Exposure. Jennifer Logue, Andrew Lambe, Kara Huff-Hartz, Allen Robinson, Neil Donahue, Mitch Small, Cliff Davidson, Darrel Stern, Jason Maranche . Project Objectives.
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Air Toxics in Allegheny County: Sources, Airborne Concentrations, and Human Exposure Jennifer Logue, Andrew Lambe, Kara Huff-Hartz, Allen Robinson, Neil Donahue, Mitch Small, Cliff Davidson, Darrel Stern, Jason Maranche
Project Objectives • What are the concentrations and health risks of air toxics in Allegheny County? • How do the concentrations and risks in Allegheny County compare to other U.S. Cities? • What are priority air toxics for Allegheny County? • What are the sources of these priority toxics?
Baseline Monitoring (2/06-1/08) Heavily Industrialized Downtown • 32 organic air toxics • 1 in 6 day sampling • Methods TO-11A & TO-15 Flag Plaza Regional background (background)
Air toxics considered in analysis Baseline: 38 HAPs Intensives: 38 HAPs Archive:
Identifying Priority Toxics • Large Local Sources • High Concentrations Relative to National Data • High Risk
Comparisons with National Concentration Data *Sonoma Tech. provided national data
25 12 4:1 2:1 1:1 Spatial variation and local sources
3 toxics above 10-5 Formaldehyde Benzene Trichloroethene 12 toxics above 10-6 Cancer Risk
Additive Cancer LIR at Baseline Sites Trichloroethene Flag Plaza Avalon Formaldehyde Benzene Stowe South Fayette 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Cancer LIR (x 10-4)
0 0.5 1.0 1.5 Cancer LIR (x 10-4) Comparison of LIR in Select U.S. Cities
Non-Cancer Risks • Chronic • Acrolein • No Acute
Other Air Toxics • Downtown: • Diesel Particulate Matter • Avalon • metals • Archived CMU Supersite Data (regional background) • Diesel Particulate Matter • Metals • Polycyclic aromatic hydrocarbons
Diesel particulate matter • Complex pollutant • 40-80% BC or EC • Organics • Sulfate • No way to directly measure • Estimate using source apportionment model • BC/EC • Hopanes & steranes • n-alkanes • aromatics
Cancer LIR (x 10-3)* 3 0 1 2 Schenely Park 0.4 Downtown Probability 0.2 0.0 0 2 4 6 8 10 DPM (g m-3) Diesel Particulate Concentrations and Risks 2.5 2.0 1.5 BC or EC (g m-3) Archived Data 1.0 0.5 0 Florence Downtown Hazelwood Greensburg Lawrenceville Schenley Park *Based on CA Office of Environmental Health Hazard Assessment URE for DPM
Risk of metals in different cities * * * * * * 1 2 3 4 5 6 7 Cancer LIR (x 10-5)
Air Toxics of Interest High Greatest Health Risks :diesel PMbenzene formaldehyde Medium Health Risks :carbon tetrachloride 1,3-butadiene tetrachloroethene acetaldehyde trichloroethene acrolein 1,4-dichlorobenzene metals Potential Concerns :chloroform propionaldehyde styrene ethylbenzene toluene methylene chloride MIBK xylenes
Intensive Monitoring Downtown Heavily Industrialized Diamond Building Carnegie Mellon
Automated Field InstrumentGas Chromatograph Mass Spectrometer/ Flame Ionization Detector (GCMS/FID) (Millet JGR, 2005) • 1 hour resolution • 70+ compounds • Low detection limit(<.2mg/m3)
High Time ResolvedMeasurements Neville Island Downtown
High time resolved measurements Concentration (mg/m3) Concentration (mg/m3) Hour of the day
0 Source Apportionment Coke Factor 270 90 270 90 180
Formaldehyde • Sources: • Secondary Formation • Mobile sources • Point Sources: 9 TPY • Predominately Secondary • Avalon is statistically significantly higher than other sites • 27% [0% 57%] increase from SF
Avalon: ACSA Downtown: Dry Cleaning Tetrachloroethene Downtown Avalon Background Avalon ACSA
Conclusions • Priority air toxics • Substantial risk from regional air toxics • Formaldehyde • Carbon tetrachloride • Local risk drivers • DPM • Benzene • Chlorinated compounds
Acknowledgments • Funding • Clean Air Fund • EPA
1,4-dichlorobenzene Downtown Downtown Background
Sources Mobile sources Point Sources: 9 TPY HQ>1 at all sites Predominately Diesel emissions Acrolein
Propionaldehyde is high throughout the county Highest in Fall Formaldehyde, Carbon Tetrachloride, and Chloromethane are on par with nation Regional Sources
Benzene in Avalon Neville Industry Mobile sources Toluene both sites Industry Mobile sources Small Local Sources
Chlorinated Compounds downtown Hydrogen sulfide and styrene at Avalon Large Regional Sources
Air Toxics Health Risks Cancer Respiratory Problems Birth Defects Neurological issues Developmental Problems Other health issues • Two types of risk • Cancer: chronic • Non-Cancer: Acute, intermediate or chronic • Risks are modeled using a linear no-threshold model Air Toxics
Determining Sources: Increased Resolutions of Hourly measurements
Plume events drive local exposure Neville Island Downtown
Benzene • Mobile Sources • Industrial Sources • High Relative to the National Data
Water Treatment Factor 0 30 330 60 300 270 90 Tetrachloroethylene 240 120 ACSA Toluene 210 150 180 Factor Contribution vs. Wind Direction ACSA Emission Profile PMF Factor
Inlet for GCMS/FID Automated Valve Assembly Compound traps Gas Chromatograph Mass Spectrometer Flame Ionization Detector
Plume Events Neville Island Downtown Styrene Toluene Benzene 40 Compounds were measured hourly
Positive Matrix Factorization (PMF) Measured Data • Main issue: Identifying factor • Event profiles • Inventory profiles PMF solves: compound c11 c12 c13 c21 c22 c23 c31 c32 c33 time scores loadings source compound fs11 fs12 fs21 fs22 fs31 fs32 a11 a12 a13 a21 a22 a23 source time