JAC Talk, 121103

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JAC Talk, 12/11/03

• Monitoring network in Paso del Norte (annotated
  maps)
• Purpose of CATMN, Benzene 1,3 Butadiene
  trends.
• Purpose of PAH, comparisons across South TX
  sites for Phenanthrene Pyrene.
• Purpose of Carbonyls, trends for species.
• Purpose for Auto-GCs, trends for species.
• Summary about El Paso air Aside from
  wind-blown dust, air is okay.

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Paso del Norte bowl traps pollution beneath
inversions
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El Paso Juarez Area Sites
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Urban El Paso Juarez Sites
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CATMN Program

• CATMN Community Air Toxics Monitoring Network.
• 5 sites in El Paso (Womble, Ascarate, Chamizal,
  Sun Metro, UTEP), earliest in 1993, authorized by
  Legislature.
• Some 88 targeted VOC species.
• Mission to determine potential community
  exposure long-term health effects, to identify
  sources of targeted compounds, and to assess
  trends.
• Quality objectives 95 confidence intervals
• Detection limit (DL) generally lt 0.5 ppbV
• /- 25 precision (reproducibility)
• /- 30 accuracy ( difference to standard)
• 75 minimum data return per quarter

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CATMN Benzene Trend
Units in parts per billion volume Womble Sun
Metro Ascarate Chamizal UTEP
Annual ESL 1 ppbV
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CATMN 1,3 Butadiene Trend
Units in parts per billion volume Levels low and
trends flat at all sites
Annual ESL 5 ppbV
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PAH Sampling Network

• PAH Polynuclear Aromatic Hydrocarbon, large
  ring aromatic hydrocarbons. Exist in urban air
  in gaseous or aerosol phase from combustion
  processes.
• Samples taken with PUF sampler, 24-hour
  integrated sampling at Sun Metro (481410053).
• PAH levels are compared to ESLs.
• Highest species concentrations Phenanthrene
  Pyrene.
• Method changes make trends not meaningful.
• Quality objectives 95 confidence intervals
• Detection limit (DL) variable, up to 0.4 ng/m3
• /- 30 precision (reproducibility)
• /- 50 accuracy ( difference to standard)
• 80 minimum data return per quarter

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PAH Phenanthrene Comparisons
Annual means Units in ng/m3 Sun
Metro/QA Laredo/QA Brownsville Edinburg Mission
Annual ESL 50ng/m3
Notes 2003 has 1st quarter only. Method change
in 2003 led to higher sample recovery, thus trend
not meaningful.
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PAH Pyrene Comparisons
Annual means Units in ng/m3 Sun
Metro/QA Laredo/QA Brownsville Mission Edinburg
Annual ESL 50ng/m3
Notes 2003 has 1st quarter only. Method change
in 2003 led to higher sample recovery, thus trend
not meaningful.
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PAMS (Auto-GC Carbonyl) Network

• Data used to understand O3 formation, track VOC,
  NOx EIs, trends, and nonattainment. Further
• Assess feasibility need for long-term or
  extensive toxic or photochemical monitoring.
• Identify track hazardous compounds identify
  sources.
• Are pollutants contributing factor to health
  problems?
• Assess temporal variations of pollutants
• Track point, mobile, area, biogenic sources.
• Identify trends.
• Provide database to plan, develop, evaluate
  diffusion models control strategies.

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Carbonyl Details

• Carbonyls oxygenated hydrocarbons C1-C9
• 24-hour integrated samples, 16 species reported
• Quality objectives 95 confidence intervals
• Detection limit (DL) 0.01-0.06 ppbV
• /- 25 precision (reproducibility)
• /- 30 accuracy ( difference to standard)
• 75 minimum data return per quarter

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Chamizal Carbonyl Findings

• Formaldehyde (HCHO) has highest levels, followed
  by Acetone Acetylene.
• Levels comparable to other cities in TX.
• Trends appear to be flat.
• Levels below ESL.
• Following graphs show results of every 6th day
  sampling with a moving spline fit.
• Later graphs compare Chamizal to other cities.

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Carbonyl every 6th day
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Carbonyl every 6th day II
Short-term ESL 12 ppbV
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Carbonyl every 6th day III
Acetaldehyde Short-term ESL 50 ppbV Acetone ST
ESL 2500 ppbV
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Carbonyl every 6th day IV
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Quarterly Mean HCHO in Texas
Units in ppbV
Houston-Clinton Dr. Houston-Deer
Park Houston-Haden Rd. Houston-Channelview Fort
Worth-NW El Paso-Chamizal Dallas-Hinton Dr.
Long-term ESL 1.2 ppbV
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Auto-GC Details

• Species O3 precursor hydrocarbons C1-C10
• 40 min. sample each hour, 45 species reported
• Quality objectives 95 confidence intervals
• Detection limit (DL) 0.05-0.60 ppbC (note units)
• /- 20 precision (reproducibility at DL)
• /- 25 accuracy ( difference to standard)
• 75 minimum data return per quarter

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Auto-GC Findings

• Trends for toxics (Benzene 1,3 Butadiene appear
  to be downward. (RFG?)
• Following graphs show annual means for B 1,3 B.
  (B trend is stat. signif., 1,3 B not)
• Subsequent graphs show variability by wind
  direction look at ratio w Acetylene, a tracer
  for vehicle exhaust, see constant levels.
• Conclusion motor vehicles main source of HCs.

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Auto-GC Toxics Trends
1997-2002 annual mean 1,3 Butadiene, units in
ppbC
1995-2002 annual mean Benzene, units in ppbC
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Mean HCs by WDR
ppb-C
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HCs Ratio to C2H2
Ratio
Propane Ethane from nat. gas, others from
exhaust
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Conclusions

• Monitoring helps us to
• Assess human exposure to toxics findings show
  some need for more attention
• Assess trends related to pollution controls
• Arrest concerns that may exist about potential
  exposures