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The Smallest Things Have the Biggest Impact: Particles in your lungs and your community . Sacramento April 25, 2005 Thomas A. Cahill,
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The Smallest Things Have the Biggest Impact:Particles in your lungs and your community. Sacramento April 25, 2005 Thomas A. Cahill, Member, Health Effects Task Force (HETF), American Lung Association – Sacramento Emigrant Trails (ALASET)Professor, Physics and Atmospheric Sciences and Head, DELTA* Group, UCD
What is the ALA-SET Health Effects Task Force? • Formed in 1994 • Modest grants to ALA-SET from • Sacramento Metropolitan AQMD, Norm Covell, and • Yolo Solano AQMD, Larry Greene • Jan Sharpless, Chair; Betty Turner, ALA-SET coordinator • Typically 8 volunteers • Presently UC Davis (2), Sac Public Health, ARB, DHS (2), SMAQMD, Sierra Research, an MD, and ALA statewide, with ALASET, Project Clean Air, and High School Environmental Assessment Project liaison, plus DHS and Kaiser Permanente collaborators • Access to sampling equipment, sampling sites, & analysis
ALA-SET HETF Particulate Studies; particles in the fine (< 2.5μm), very fine (< 0.25 μm), ultra-fine (< 0.1 μm) modes • Stroke and ischemic heat disease mortality vs air quality, Central Valley of California • 1998 • Sacramento I-5 aerosol transect • Phase 1, 2002-2003 • Sacramento I-5 aerosol transect • Phase 2, 2003-2004 • High School air quality evaluations 2005
C TSP (pre-1987) PM10 PM0.25 ? PM2.5
Total Suspended Particulate mass TSP < 35 μm Inhalable Aerosols PM10 < 10 μm Fine Aerosols PM2.5 < 2.5 μm Very fine aerosols, < 0.25 μm, ultra fine aerosols, < 0.10 μm 35 to 10 μm, mostly natural Dust, sea salt, pollen, … 10 to 2.5 μm, largely natural Dust, sea spray, some nitrates 2.5 to 0.25 μm, mostly man made Fine dust, nitrates, sulfates, organics, smoke 0.25 to circa 0.01 μm, almost entirely man made; high temperature combustion, heavy organics, soot, metals Deep lung deposition Particulate Matter in the Atmospheric The Atmospheric Aerosol
Why were these HETF studies initiated? • New information became available • CORE Report on IHD and stroke death rates 1989 - 1991 • New PM10 data in California after 1987 • U. Minnesota/DRI/DELTA Group diesel studies • Tuscarora tunnel studies Gertler et al HEI 2002 • U. Minnesota truck emissions Watts/Zielinska/Lawson 2002 • Local information was lacking • Near roadway concentrations • New techniques became available • Sampling • DELTA Group DRUM sampling technology • NSF ACE-Asia samplers became available • Analysis • Soft beta mass at UCD, S-XRF analysis at LBNL
Spatial patterns of Ischemic Heart Disease mortality versus PM10, 1989-1991
Health Impacts of Valley Aerosols For winter, 120 ug/m3, r2 = 0.69
and Sacramento is only marginally better for fine particles…..
Here there be cows Wind Bay Area to Bakersfield Wind Bakersfield to Bay Area Rain 3 mm Cold, down-slope Hot, up-slope
Health effects of aerosols • Statistical certainty that fine PM2.5 mass correlates well with death and illness • Example: Dockery et al 1994; ALASET HETF Study, 1998 • Theoretical analysis, animal and laboratory studies show most PM2.5 mass is harmless in ambient levels • Causal components of PM2.5 that are harmful – uncertain; best candidates? (Devlin EPA 2003) • Acidic aerosols • Biological aerosols • Fine Transition metals • Very fine/ultra fine insoluble particles • High temperature organics
Sacramento – I-5 Transect Studies: 2002 – 2003 and 2003-2004; New data from DELTA Group collaborations • Laboratory studies – NREL/U. Minnesota/DRI diesels; UCD S-XRF analysis –(Lawson, Watts, Zielenska et al.), plus DRI Lube oil (Fujita) • Prior field studies – prior ARB/UC Davis work; HEI/DRI Tuscarora Tunnel (Gertler et al 2002) • Quasi-ambient and ambient ALASET - HETF applications • Interstate 5 and downtown Sacramento • Downwind of Watt Avenue
U. Minn. Dynamometer Diesel tests Fuel Lube oil
PM 0.25 ? PM 10 PM 2.5 Average Zn to mass, all DRI tests, 1800 1300
Highway emissions • Laboratory tests have proven useful for process but unreliable in on highway tests • Highways studies are of two major types – • Lateral transverse studies • Tunnel studies • Highway studies are hard and expensive – • Define traffic and meteorology • Measure vast numbers of gasses and particles over a short periods of time
Now cars are becoming the largest component of toxic very fine aerosols
Comparisons of trucks and cars from the Tuscarora Tunnel study
New techniques and NSF ACE-Asia samplers: DELTA Group 8 DRUM Impactor • 8 size ranges: • Inlet ( ~ 12) to 5.0 μm • 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 • 10.4 l/min, critical orifice control, ¼ hp pump • 6.5 x 168 mm Mylar strips • For 42 day run, 4 mm/day, time resolution = 1 hr. • Field portable • 10 kg, 43 × 22× 13 cm 43 cm
Example of very fine 0.26 > Dp > 0.09 μm particles from near Highway 50, South Lake Tahoe
Typical DELTA Group ALS S-XRF x-ray spectrum taken at a clean site in 30 sec
Quality assurance tests of the DELTA Group S-XRF analyses through 3rd party comparisons
Note: The DRUM sees almost twice as much soil elements as Dichots and the RAAS, partially associated with the anomalous soil size at Fresno and the much sharper DRUM size cuts.
DRUM S-XRF vs ARB XRF and ARB RAASnote: it takes 24 6 hr 6 size cuts S-XRF measurements to match a single 24 hr PM2.5 filter
Lung Assoc. Sacramento Transect Study Site Map and PM2.5 aggregated data #1, #3 - light blue = rain, yellow = “clear”, rest = fogs, wet and dry I-5 Hwy-50 I-80 I-80 Hwy-99
Crocker Art Museum Sacramento River Site ARB Site Figure 8 Map of Downtown Sacramento sites.
Predicted vf mass from DRI data 7.2 ±5.0 g/m3 Predicted mass from DRI data 4.8 ±3.2 μg/m3
Measured mass 25 ± 15 μg/m3 Measured mass 6 ± 2 μg/m3
Why is downtown Sacramento bathed in very fine (and presumably ultra-fine) diesel/smoking car exhaust on those days?
The wind was blowing directly across the raised WX (I-80 business) freeway Effect of roadway distance and configuration on downwind concentrations of lead (Cahill et al, ARB 1974) 1.
We also see very fine aerosols characteristic of diesels/smoking cars at Fresno; effect of Hwy 99? Predicted diesel vf/uf mass 11/25 – 12/17, 9 ± 6 µg/m3
We can now measure mass directly by soft beta ray transmission from the DRUM strips
Measured total very fine mass , 8.8 ± 2.0 μg/m3 , vs. predicted diesel/smoking car mass, 9 ± 6 μg/m3
Aerosol Information from DRUM particle size analysis shows the presence of very fine particles
Study of ultrafine particles near a major highway Zhu et al (2002); Lead from Cahill et al (ARB, 1974) Nearest freeway 3 miles BC, number -diesels CO, Pb - cars
Fine particulate pollution in Sacramento; What did we learn? • Sacramento, Fresno, and Los Angeles are impacted by very fine/ultra fine diesel and smoking car aerosols even at distances well away from roadways. • Most serious problem – effect of arterials on schools, hospitals, nursing homes… • Sac. Amer. Lung Assoc bill (Oct, 2003) requires and air quality evaluation of any school < 500 ft • Sacramento is severely impacted by the San Joaquin Valley and Hwy 99 aerosols in winter • I-5, the W-X Freeway, and other major roadways are sources of the most worrisome (Devlin, EPA, 2003) types of particles over large areas of Sacramento • Very fine high temperature organics, metals, and soot • The ALASET HETF, with modest funding, was able to execute a transect of a major urban region with unparalleled detail.
What does the HETF propose? • Initiate the process to make car exhaust a Toxic Air Contaminant (TAC) like diesel • Diesel by itself is 70% of all the cancer risk from all TACs combined, and car exhaust may be worse per unit mass • Initiate actions to remove the gross emitting cars and trucks off California highways • Only a few percent of each generate more that ½ of all roadway pollutants Note that even if 2/3 of the cleanest California vehicles became Zero Emission Vehicles, there would be little change in total highway pollution if we haven’t addressed the gross emitters.
What does the HETF propose? • Initiate actions to have California adopt a new very fine particle mass standard directly designed to address these very fine and ultra fine particles • The most toxic components almost all lie in particles below roughly 0.30 μm to 0.15 μm diameter • Development of mitigation strategies – • At the source (see above) • Transport from sources to receptors (road design, buffer spaces (viz. schools > 500 ft), vegetation barriers,…) and • receptor mitigation strategies (air intake options, indoor HEPA filters, plants, low indoor emissions…)
What next for ALASET HETF? High School Environmental Assessment project • New ALASET and HETF collaboration with local high school students • Self evaluation of local air impacts at three high schools • Mira Loma • Luther Burbank • Davis • Loan of UC Davis DELTA Group equipment • Includes very fine/ultra fine aerosols by mass and composition • Joint analysis of air samples by size, time, and composition (with ALASET HETF funding) • Development of a “template” for wide use in high schools
Mira Loma students with ALASET coordinator (Shelley Mitchell, at left), and DELTA 3 DRUM air sampler (middle on bench)