Transcript Slide 1

Atmospheric Aerosols: Health, Environmental and Policy of
Particulates in the US-Mexico Border Region
July 14, 2005
2003 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
Background Rate
(case-persons-yr)
Risk Coefficient
(% per 10µg/m3)
Risk Reduction
(cases/yr)
Cohort
Mortality
10/1000
3
2000
Time Series
Mortality
5/1000
1
1000
Chronic
Bronchitis
14/1000
10
10 000
Ozone
Background Rate
(case-persons-yr)
Risk Coefficient
(% per 10µg/m3)
Risk Reduction
(cases/yr)
Time Series
Mortality
5/1000
0.5
300
Minor Restricted
8000/1000
1.0
2,000,000
PM10
Activity Days
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
Percentage of emissions from the MCMA
in 2000 by source category
PM2.5
Electricity
generation
3%
Industrial
combustion
3%
PM10
Chemical
industry
4%
Other
5%
HD-diesel Vehicles
Manufacturing
industry 6%
32%
Other
transport
7%
Vehicles
< 3 ton 8%
Metals
industry
9%
Other
transport
10%
Buses
15%
Private
cars
12%
HD- diesel vehicles
20%
Vehicles
< 3 ton 5%
Soil
erosion
6%
Other
7%
Soil
erosion
17%
Buses
9%
Private
cars
9%
Manufacturing
industry 13%
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
Mobile Laboratory Modes of Operation
February 2002 & April 2003
Stationary Sampling
High time resolution point sampling
Quality Assurance for conventional
air monitoring sites
Mobile Sampling/Mapping
Motor vehicle pollution emission ratios
Large source plume identification
Ambient background pollution distributions
Tula
Cuautitlan
Teotihuacan
CENICA
Chase
Detailed mobile source
emissions characterization
Plume tracer flux measurements
Ajusco
Chalco
Aerosol Mass Spectrometer (AMS) at CENICA
100% transmission (60-600 nm), aerodynamic sizing, linear mass signal.
• Jayne et al., Aerosol Science and Technology 33:1-2(49-70), 2000.
• Jimenez et al., J. Geophys. Res.- Atmospheres, 108(D7), 8425, doi:10.1029/ 2001JD001213, 2003.
Aerosol measurements (April 15-17, 2003)
35
-3
PM1.0 Mass Concentration (g m )
30
Nitrate
Water
Organics
Chloride
Sulphate
Ammonium
PAH
25
20
15
10
5
0
12:00 AM
4/15/2003
12:00 PM
12:00 AM
4/16/2003
12:00 PM
12:00 AM
4/17/2003
12:00 PM
PM2.5 Concentration
“In-plume” Sampling
indicated by above-ambient CO2 levels
Gas or Particle Signal
DSignal
Emission
perturbed level
800
700
CO2 (ppm)
DCO2
600
500
400
300
17:54
7/10/01
17:55
17:56
Time
17:57
17:58
Emission Ratio = DSignal / DCO2
Ambient
background
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
C
150
200
X-ray intensity
200
X-ray intensity
250
Only Carbon
100
50
S, K inclusions
C
150
100
50
Cu
Cu
O
S
O
0
K
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.0
0.5
1.0
1.5
2.0
keV
2.5
3.0
3.5
4.0
4.5
5.0
3.5
4.0
4.5
5.0
keV
300
280
260
250
O
240
Si
C
S inclusion
200
200
180
X-ray intensity
X-ray intensity (a.u)
220
160
140
120
100
Si inclusion
Cu
C
80
150
100
60
(Source: MIT/PNNL)
40
50
O
Cu
S
20
0
0.0
0.5
1.0
1.5
2.0
keV
2.5
3.0
3.5
4.0
0
0.0
0.5
1.0
1.5
2.0
2.5
keV
3.0
Processing of Soot
From “Chase” Studies
In Ambient Air
500 nm
2 µm
40
70
65
C
60
in city traffic
PIXE
Spectra
40
35
30
25
20
25
S
O
20
15
10
O
15
at CENICA
30
50
45
Processed soot
C
35
X-ray intensity (a.u)
X-ray intensity (a.u)
55
Fresh soot
10
5
S
5
0
0
0.0
0.5
1.0
1.5
keV
2.0
2.5
3.0
0.0
0.5
1.0
1.5
keV
2.0
2.5
3.0
MCMA 2003: Glyoxal and SOA precursors
Glyoxal
Aromatic
VOCs
SOA Precursors
• Benzene, Toluene, Styrene
• m-xylene, p-xylene, ethylbenzene
• Benzaldehyde, Phenol, pCresol
• Naphtalene
• HCHO, Glyoxal (DOAS-2)
0.000
First time DOAS
detection of
Glyoxal in the
atmosphere
relative units
DOAS-1
L= 860m
H= 16m
0.005
residual
Glyoxal + residual
scaled Glyoxal reference (1.2ppb)
420
430
440
450
SOA
460
Wavelength [nm]
CENICA
East
South
South-West
Conclusions: PM Measurements
• Rich PM dataset during MCMA-2003
• 58% 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