Continuous Analysis of Continuous Analysis of Fresno Aerosols by Size, Fresno Aerosols by Size, Time, and Elemental Time, and Elemental Concentrations, Concentrations, March – December, 2001 March – December, 2001 Thomas A. Cahill, Steven S. Cliff, Thomas A. Cahill, Steven S. Cliff, Michael Jimenez-Cruz, and Michael Jimenez-Cruz, and 1 Kevin Kevin D. Perry, D. Perry, DELTA Group, University of DELTA Group, University of California, Davis, California, Davis, http://delta.ucdavis.edu http://delta.ucdavis.edu and and 1 Dept. of Meteorology. University Dept. of Meteorology. University of Utah of Utah
Continuous Analysis of Fresno Aerosols by Size, Time, and Elemental Concentrations, March – December, 2001. Thomas A. Cahill, Steven S. Cliff, Michael Jimenez-Cruz, and 1 Kevin D. Perry, DELTA Group, University of California, Davis, http://delta.ucdavis.edu and - PowerPoint PPT Presentation
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Continuous Analysis of Fresno Continuous Analysis of Fresno Aerosols by Size, Time, and Aerosols by Size, Time, and Elemental Concentrations,Elemental Concentrations,
March – December, 2001March – December, 2001
Thomas A. Cahill, Steven S. Cliff, Michael Thomas A. Cahill, Steven S. Cliff, Michael Jimenez-Cruz, and Jimenez-Cruz, and 11Kevin D. Perry, Kevin D. Perry,
DELTA Group, University of California, Davis, DELTA Group, University of California, Davis, http://delta.ucdavis.eduhttp://delta.ucdavis.edu and and
11Dept. of Meteorology. University of UtahDept. of Meteorology. University of Utah
Purpose of the StudyPurpose of the StudyFresno, California, has one of the highest
childhood asthma rates in California.
Fresno also is in violation of state and federal air quality criteria –
Ozone, PM10 in summer
PM10 and PM2.5 in winter
To what degree does Fresno air pollution impact the short term childhood asthma rate?
Health and Aerosols in the Central Valley of CaliforniaData Relative to Shasta and Butte counties
Get a wide variety of aerosol transition metals as a function of size and time to support short term medical data for the Fresno
Asthmatic Children’s Environment Study (FACES)
Original design: PM10 and PM2.5, day – night, 2 stage DRUMNot possible: Mis-sizing by too few cut points (coarse); Too much loading (accumulation mode); loss of sub-0.25 μm particles
Final design:8 size modes 10.0 μm to 0.09 μm
Why? EPA/IMPROVE 8 DRUM QA; very fine modes;
3 hr time resolutionWhy? Identification of sharp metal concentration episodes
Consequence: Needed to examine over 1500 time periods, 12,000 samples,
and yielding over 1/3 million S-XRF elemental values; but … $$$
Fog days at Fresno x 5, no rainRain prev 5 days, Fresno
24 hr Nitrate AerosolsFall, 2002
Wind Bay Area to Bakersfield
Wind Bakersfield to Bay Area
Rain 3 mm
Cold, down-slope
Hot, up-slope
Here there be cows
.
.
ImplementationImplementation• Sampling: a PM10 modified DELTA Group
slotted DRUM impactor, with size cuts at 10, 5, 2.5, 1.15, 0,.75, 0.56, 0.34, 0.26, and 0.09 μm aerodynamic diameter (Raabe-Marple values).
• Analysis: Synchrotron x-ray fluorescence (S-XRF) at the DELTA Group x-ray microprobe of the Advanced Light Source, Lawrence Berkeley National Laboratory.
• Quality Control: – Routine re-analysis of previously analyzed samples,– Comparison with side by side Dichot samplers,– Re-analysis of ARB Dichot samples,– Comparisons with IMPROVE PIXE, XRF.
DELTA Group slotted 8 DRUM DELTA Group slotted 8 DRUM ImpactorImpactor
• 8 size ranges:• 10.0 to 5.0 μm (std PM10 inlet)• 5.0 to 2.5 μm• 2.5 to 1.15 μm• 1.15 to 0.75 μm• 0.75 to 0.56 μm• 0.56 to 0.34 μm• 0.34 to 0.26 μm• 0.26 to 0.09 μm
• 16.7 l/min, critical orifice control, ¼ hp pump
• 10.0 x 168 mm Mylar strips• For 42 day run, 4 mm/day, S-XRF beam 0.5 mm, = 3 hr.• Field portable
DELTA Group Synchrotron-XRF DELTA Group Synchrotron-XRF Facility at the LBNL Advanced Light Facility at the LBNL Advanced Light
SourceSource
For scale? (At least it’s not duct tape.)
Typical S-XRF Spectrum Typical S-XRF Spectrum Raw data, Teflon substrate with no blank subtractionRaw data, Teflon substrate with no blank subtraction
Energy (keV)4 8 12 160
1
10
100
1000
10,000
100,000
Cou
nts
Na 150
100
14
Si 6 23 3S 4 20 3V 1 6 0.1Ni 0.9 0.9 0.2As 1.7 0.5 0.1Sr 2.3 1.3 0.3Cd 7.6 NA NABa 84 NA 1.0Pb 4 2 0.6
RT
I X
RF
IMPR
OV
E
S-X
RF
MDL values(ng/cm2)
Nic
kel
Pot
assi
um
Van
adiu
mM
anga
nes
e Iron
Cop
per Zin
c
Bro
min
eR
ub
idiu
mFlu
orin
e
Su
lfu
r
Ars
enic
an
d L
ead
Cal
ciu
m
Str
onti
um
0 5 10 15 20 25
ARB Dichot ng/m3
0
5
10
15
20
25
AR
B R
AA
S n
g/m
3Fresno FACES Filter Intercomparison
ARB Dichot vs ARB RAASZinc
0 5 10 15 20 25
DELTA Group S-XRF ng/m3
0
5
10
15
20
25
AR
B D
ich
ot,
AR
B R
AA
S n
g/m
3
ARB Dichot ARB RAAS
DELTA S-XRF vs ARB Dichot and ARB RAAS FiltersZinc
All filters S-XRF
vs ARB XRF
1.02 0.11
vs ARB RAAS
1.29 0.58
ARB XRF vs ARB RAAS
1.29 0.63
DRUM S-XRF vs ARB XRF and ARB RAASDRUM S-XRF vs ARB XRF and ARB RAASnote: it takes 24 6 hr 6 size cuts S-XRF measurements to note: it takes 24 6 hr 6 size cuts S-XRF measurements to
match a single 24 hr PMmatch a single 24 hr PM2.52.5 filter filter
PM-2.5 Zn Concentration vs. Date (6-hour data)
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
3/10/01 3/20/01 3/30/01 4/9/01 4/19/01
ng/
m^
3
DRUM -Zn RAAS-Zn Dichot-Zn
The DRUM sees more soil, almost all The DRUM sees more soil, almost all lying between 2.5 and 1.15 lying between 2.5 and 1.15 µmµm
0 100 200 300 400 500 600
FRM - SASS ng/m3
0
100
200
300
400
500
600
700
Dic
hot, D
RU
M n
g/m
3
Dichot DRUM
Silicon Dichot vs FRM
11
11
22
22
33
33
44
44
45
55
56
66
67
77
77
88
88
99
99
910
1010
1011
1111
1112
1212
1212
Month of the year, 2001
0
20
40
60
80
100
120
Mic
rorg
am
s/m
3
PM2.5 Mass, 2001
Aerosols at the Fresno 1st Street Supersite
EPA 24 hr standard
EPA annual standard
1014
1923
2731
48
1216
2024
293
711
1519
2327
15
913
1721
2529
37
11
March April May June July, 2001
0
1000
2000
3000
4000
5000
6000
7000
8000
Na
no
gra
m/m
3
PM10 PM2.5
Silicon Aerosols at Fresno during the FACES StudyDRUM Impactor, S-XRF Analysis Data, 6 hr resolution
1216
2024
281
59
1317
2125
292
610
1418
2226
304
812
1620
2428
15
913
1721
2428
26
1014
18
July August September October November December, 2001