Contributions of Organic Compound Pollutants to Ozone and Fine Particulate Matter in Mexicali, Mexic

1
Contributions of Organic Compound Pollutants to
Ozone and Fine Particulate Matter in Mexicali,
Mexico

• Jonathan O. Allen, Daniel A. Gonzales, Qinyue Sun

Berk Knighton Montana State University Alberto
Mendoza, Adriana A. Gutierrez, Erik I. Pardo
Instituto Tecnogico y de Estudios Superiores de
Monterrey
12 Dec 2006
SCERP Research Meeting
2
Atmospheric Sampling
13-22 April 2005 at Universidad Autonoma de Baja
California
At UABC SUMMA cannisters Quadrupole Aerosol Mass
Spectrometer High volume impactor In Aerodyne
Mobile Lab Proton Transfer Reaction Mass
Spectrometer Quadrupole Aerosol Mass
Spectrometer Tunable Infrared Laser Differential
Absorption Sensor Infrared Hygrometer Chemilumines
cence (NOx) Monitor (Funded by LASPAU)
3
Volatile Organic Compounds
High concentrations mornings and evenings with
low wind Low concentrations in afternoons due to
vertical mixing
4
Analysis of VOC Data

• Vehicle emission contributions to VOCs
• High correlation between ethene, propylene and
  benzene
• Benzene/toluene ratio of 0.4
• Strong correlation between TNMOC and CO
• VOC contributions from non-catalyst equipped
  vehicles
• Ethene/acetylene ratios (0.8)
• Little photochemical oxidation (nearby sources)
• Xylenes/benzene ratio 2
• Stable and high VOCs since 1997

aZielinska et al., 1999 b Fujita et al., 2004
5
Quadrupole Aerosol Mass Spectrometer
Quantitative speciation of nonrefractory PM1.0
every 5 min
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PM1.0 Composition
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PM Conclusions

• Organic compounds were the most important
  component of nonrefractory PM1.0. The temporal
  evolution suggests vehicle source.
• Concentrations of PAHs and hopanes suggest
  vehicles as main PM source.
• Additional, less important sources of PM are
• cooking as indicated by cholesterol
• agricultural dust as indicated by odd-numbered
  normal alkanes associated with coarse PM.
• Local sources and meteorology explains hourly and
  daily variations in concentration.

8
Acknowledgements

• Funding by EPA under Federal Grant/Contract No.
  XA-83239201-0 as part of the Southwest Consortium
  for Environmental Research and Policy programs
• Municipality of Mexicali
• Mexicalis air quality monitoring network
• Universidad Autónoma de Baja California

Volatile organic compounds in the downtown area
of Mexicali, Mexico during the spring of 2005
Analysis of ambient data, A. Mendoza, A. A.
Gutierrez, E. I. Pardo, and J. O. Allen. Air and
Waste Management Assoc. Conference, 2006.