Atmospheric Aerosols: Health, Environmental and Policy of Particulates in the US-Mexico Border Region July 14, Field Measurement Campaign Mexico City Metropolitan Area Mario Molina University of California, San Diego Mario Molina Center, Mexico City

Summary of the First Phase of the Mexico City Air Quality Program Chapter 1. Air Quality Impacts: A Global and Local Concerns Chapter 2. Cleaning the Air: A Comparative Overview Chapter 3. Forces Driving Pollutant Emissions in the MCMA Chapter 4. Health Benefits of Air Pollution Control Chapter 5. Air Pollution Science in the MCMA: Understanding Source-Receptor Relationships Through Emissions Inventories, Measurements and Modeling Chapter 6. The MCMA Transportation System: Mobility and Air Pollution Chapter 7. Key Findings and Recommendations (Kluwer Academic Publishers, 2002)

Visibility in the Mexico City Metropolitan Area

Estimated Health Benefits of a 10% Reduction of Pollution Levels in the MCMA PM10 Background Rate (case-persons-yr) Risk Coefficient (% per 10µg/m3) Risk Reduction (cases/yr) Cohort Mortality 10/ Time Series Mortality 5/ Chronic Bronchitis 14/ Ozone Background Rate (case-persons-yr) Risk Coefficient (% per 10µg/m3) Risk Reduction (cases/yr) Time Series Mortality 5/ Minor Restricted Activity Days 8000/ ,000,000 Chapter 4. Health Benefits of Air Pollution Control: John Evans, Jonathan Levy, James Hammitt, Carlos Santos Burgoa, and Margarita Castillejos (2002).

Air pollution harms children's lungs for life Children exposed to higher levels of particulate matter and other air pollutants had significantly lower lung function

Other transport 10% Private cars 12% Buses 15% HD-diesel Vehicles 32% Vehicles < 3 ton 8% Other 5% Soil erosion 6% Industrial combustion 3% Electricity generation 3% Manufacturing industry 6% Other transport 7% Other 7% Metals industry 9% Buses 9% Private cars 9% Soil erosion 17% HD- diesel vehicles 20% Chemical industry 4% Vehicles < 3 ton 5% Manufacturing industry 13% PM 2.5 PM 10 Percentage of emissions from the MCMA in 2000 by source category

Summary of MCMA-2003 Field Measurement Campaign Exploratory mission (February 2002) Intensive 5-week field measurement (Spring 2003) Special Session on “Megacity Impacts on Air Quality” at the Fall 2004 AGU Meeting, San Francisco, CA Special Issue of the MCMA 2003 Campaign in ACP (Atmospheric Chemistry and Physics) NARSTO sanctioned field campaign – data will be posted on NARSTO website Photochemical/Transport Modeling in progress (CIT, MM5, CAMx, etc.) Sponsors: CAM, NSF, MIT/AGS, PEMEX, DOE, others

Chase Detailed mobile source emissions characterization Plume tracer flux measurements Mobile Sampling/Mapping Motor vehicle pollution emission ratios Large source plume identification Ambient background pollution distributions Stationary Sampling High time resolution point sampling Quality Assurance for conventional air monitoring sites Mobile Laboratory Modes of Operation February 2002 & April 2003

Aerosol Mass Spectrometer (AMS) at CENICA 100% transmission ( nm), aerodynamic sizing, linear mass signal. Jayne et al., Aerosol Science and Technology 33:1-2(49-70), Jimenez et al., J. Geophys. Res.- Atmospheres, 108(D7), 8425, doi: / 2001JD001213, 2003.

Aerosol measurements (April 15-17, 2003)

PM 2.5 Concentration

 Signal Emission Ratio =  Signal /  CO 2 “In-plume” Sampling indicated by above-ambient CO 2 levels  CO 2 Ambient background level Emission perturbed level

Vehicle Chase Experiments Kolb et al., A31D-02 / Zavala et al., A31D-08 / Knighton et al., A14A-03

Heterogeneity in a single soot particle S inclusion Only Carbon S, K inclusions Si inclusion (Source: MIT/PNNL)

Processing of Soot From “Chase” StudiesIn Ambient Air PIXE Spectra

Aromatic VOCs Glyoxal SOA Precursors SOA East South South-West MCMA 2003: Glyoxal and SOA precursors DOAS-1 L= 860m H= 16m Benzene, Toluene, Styrene m-xylene, p-xylene, ethylbenzene Benzaldehyde, Phenol, pCresol Naphtalene HCHO, Glyoxal (DOAS-2) CENICA First time DOAS detection of Glyoxal in the atmosphere

Conclusions: PM Measurements Rich PM dataset during MCMA % organics, 26% Inorg., 14% BC –Org: 2/3 OOA, 1/3 POA –Little soil / metals –Intense condensation SIA and SOA –More SOA than in chambers “Natural” Holy Week experiment PAH measurements