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Air Quality in Texas. Birnur Guven Houston Advanced Research Center June 23, 2010 – Johnson Space Center. Ozone (O 3 ). At ground-level in the air we breathe, ozone (smog) poses serious risks to human health.
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Air Quality in Texas Birnur Guven Houston Advanced Research Center June 23, 2010 – Johnson Space Center
Ozone (O3) • At ground-level in the air we breathe, ozone (smog) poses serious risks to human health. • Ozone is produced by photochemical reaction of the precursors Nitrogen Oxide (NOx) and Volatile Organic Compounds (VOC): • VOC + NOx + Heat + Sunlight = Ozone • Intense sunlight, warm temperatures, stagnant high-pressure weather systems, and low wind speeds cause ozone to accumulate in harmful amounts.
Impacts • Powerful oxidant and respiratory irritant • Damage to plants • Global warming
VOC NOx VOC
Ozone Non-attainment and Controls Trends in 8-hour ozone design values in Texas • Texas Emission Reduction Plan (TERP) • Texas Low Emission Diesel fuel standards • Vehicle Inspection and Maintenance • Transportation control measures • Emissions limits • Emissions cap and trade markets
What is Particulate Matter? U.S. EPA U.S. DOE
Impacts • increased rates of mortality, • increased rates of respiratory disease, • decreased visibility, • damage to materials • If the PM is acidic, acid deposition. Particle composition and size
Health Effects • Particles >10mm do not enter respiratory system • Mouth breathers: 50% of PM2.5 deposit in the lungs • Nasal breathers: 25% of PM2.5 deposit in the lungs • Damage to respiratory organs. • 20-60% of particles between 0.01-2.5mm penetrate into lungs and deposited there.
Effects on Visibility PM2.5 < 10 ug/m3 (8/16/00) PM2.5 = 15 ug/m3 (8/7/00) PM2.5 = 20 ug/m3 (8/24/00) PM2.5 = 25 ug/m3 (8/25/00) PM2.5 = 30 ug/m3 (8/15/00) PM2.5 = 35 ug/m3 (8/26/00) Michael Koerber Lake Michigan Air Directors Consortium
Primary and Secondary PM Primary particles Secondary particles
Why is PM2.5 different from other pollutants? Key Players in PM2.5 formation
Transport of PM What distance? PM10 particles can travel as little as a hundred yards or as much as 30 miles. PM2.5 particles can go many hundreds of miles. How long? PM10 particles can stay in the air for minutes or hours, while PM2.5 particles can stay in the air for days or weeks. The Dust of Africa – at times makes up 50% of the breathable particles in Miami (July 16, 2003) The fires of Mexico (April 16, 2003)
Design values for annual PM2.5 at selected Texas monitors Two sites of concern: Houston Aldine (18% increase to 14.6 μg/m3 from 2001 to 2006) Houston Clinton (33% increase to 16 μg/m3 from 2001 to 2006)
Data Types and Sources used in Air Quality and Exposure Research • Ambient Monitoring Data • EPA Air Quality System (AQS) – AirData http://www.epa.gov/air/data/index.html • TCEQ CAMS data – TAMIS Web Application http://www5.tceq.state.tx.us/tamis/index.cfm?fuseaction=home.welcome • TCEQ AutoGC – Available upon request – not on web yet. • Ambient data from field studies – e.g. TexAQS I and II, TRAMP, SHARP • Meteorological Data • Exposure Data from Field Studies – e.g. RIOPA and HEATS • Personal exposure, outdoor and indoor concentrations measured at residences during each visit • Questionnaires • Information concerning time and location of microenvironment where participants spent time during sampling
Data Types and Sources • National Air Toxics Assessments (NATA) http://www.epa.gov/ttn/atw/natamain/ • Emissions Inventory data from TCEQ • National Emissions Inventory (NEI) http://www.epa.gov/ttn/chief/net/2002inventory.html • Toxics Release Inventory (TRI) http://www.epa.gov/tri/ • TCEQ Emission Event Database http://www11.tceq.state.tx.us/oce/eer/index.cfm • Air Research Information Infrastructure (ARII): A Site for Houston Air Quality Data http://www.airhoustontx.org/houston/ • Air Exposure Research Online (AERO) http://aero.harc.edu/
A sample ARII screen used in the analysis of ambient ethylene data in conjunction with trajectory and emissions data
Emission events detected in ARII and influenced the olefin concentrations Trajectory for 9/1/2006 8pm
Modeling Tools Source Models: • ISCST3 • CALPUFF • CMAQ • CAMx Receptor Models: • Chemical Mass Balance • Positive Matrix Factorization • Multilinear Engine • UNMIX Watson, 1979, Dissertation; Watson and Chow 2005