Working Together for Clean Air PM 2.5 Continuous Methods Lynnwood, Washington Site

Slide 2 Study Objectives To share information regarding Continuous Fine Particle Monitoring vs the Federal Reference Method for PM 2.5 at a Woodsmoke Impacted Site To specifically compare the technologies employed by vendors in continuous fine particle monitoring To assist us in Long Term Network Management Decisions Which Device (s) should we invest in for future Fine Particle Monitoring for Woodsmoke Impacted Areas?

Slide 3 Abstract The Puget Sound Clean Air Agency has a long history of using continuous fine particle monitors in the Seattle Metropolitan Area. In an ongoing continuous improvement effort, we have used a site in a wood smoke impacted area to test new technologies for continuous fine particle monitoring. This presentation is a data update studying both the technical data issues of intercomparison and quality assurance, and the practical issues of maintenance and operations between various samplers including the Rupprecht & Patashnik TEOM (tapered element oscillating microbalance), the TEOM FDMS (filter dynamics measurement system), the Radiance Research Nephelometer, and the Met-One 1020 BAM (beta attenuation monitor) and E-BAM. The standard PM 2.5 method that will be used for comparison is the Federal Reference Method.

Slide 4 Lynnwood, Washington Site Lynnwood Site

Slide 5 Detailed Site Description Lynnwood Monitoring Site

Slide Study Design In 2003, we collected data: FRM PM in 6 TEOM PM 2.5 Nephelometer PM 2.5 TEOM FDMS PM 2.5 Looking for a measure of performance with significant aerosol volatility

Slide 7 Regression: Continuous vs FRM 2003

Slide 8 Time Series: First Half of 2003

Slide 9 Time Series: Second Half of 2003

Slide 10 Statistics – Annual Averages

Slide Study Design Look at “Wood Smoke” Season comparing: FRM PM in 3 TEOM PM 2.5 Nephelometer PM 2.5 TEOM FDMS PM 2.5 Met-One BAM PM 2.5 Met-One E-BAM PM 2.5

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Slide 16 Aethalometer Experience Dual Channel Aethalometer Project objective: to learn more about nature of Carbon Aerosol Some Surprising results… Darrington, WA Sampling Site High Concentration of Wood Smoke

Slide 17 Darrington, Washington

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Slide 19 Darrington High School

Slide 20 Dual Channel Aethalometer Graphic

Slide 21 Daily Averages

Slide 22 Hourly Averages

Working Together for Clean Air U. of Washington Diesel Exposure Lab Testing Aethalometer Pilot Experiment

Slide 24 Opportunity UW Diesel Exposure Laboratory Health Studies: Humans and Mice Principal Investigator – Dr. Joel Kaufman, MD, MPH Engineering Investigator – Dr. Tim Larson, PHD Diesel engine Current model turbocharged direct-injection 5.9 liter Cummins B-series engine (6BT5.9G6, Cummins, Inc., Columbus, IN). 100 kW generator set. Comparable to delivery trucks and school buses. Fuel Fuel is #2 un-dyed on-highway fuel from a commercial source

Slide 25 Visual Diesel Engine outside: Controlled exposure chamber inside. 30x20x8 foot chamber with instrumentation

Slide 26 Initial Study Questions What will the Aethalometer measure when we expose it to this Acute, High Pollution Level Environment? What will the ratio be between the PM 2.5 DPM being measured by the TEOM and the PM 2.5 BC being measured by the Aethalometer? How Variable? How will the Nephelometer measurements relate to the measurements taken with the other devices? What will the BC and UV channel show us about the nature of the Diesel Particulate Matter?

Slide 27 Study Objectives Learn more about both channels of the Aethalometer by testing it in the Diesel Exposure Lab Learn about the Maximum Limits of the Aethalometer Learn about the linearity of the Aethalometer over a wide range of exposures Learn about the relationship between the BC and UV channels Learn more about the TEOM and NEPH in the Diesel Exposure Lab

Slide 28 Method Monitored Air in the chamber using TEOM, NEPH, and dual channel Aethalometer at various levels of Total PM 2.5 (in this case, total Diesel Particulate Matter) Experiment lasted 9 weeks Gathered data on 7 sessions of opportunity during those 9 weeks We were able to validate 5 of those sessions (extremely high levels caused instrument malfunction) Assumption: TEOM is our Standard PM 2.5 device for this experiment. Historically, we have shown that both the TEOM PM 2.5 device, and the Nephelometer have excellent correlations with the PM 2.5 Federal Reference Method.

Slide 29 Time Synch Problem Time Synch Problem: The instrument’s clocks were not in synch. For analysis, we used the TEOM’s time standard and subjectively adjusted the other devices’ data accordingly to synch the time. Data Resolution Limiting Factor: Aethalometer 5 minute Averages. For comparison, we calculated 5 minute average data for all 3 devices.

Slide 30 PSCAA Method to Convert Bscat to PM 2.5 for Ambient Air We use a wide network of Nephelometers to monitor PM 2.5 in Snohomish, King, Pierce, and Kitsap Counties. We use a 24 Hour Average Correlation Factor to convert from Bscat to PM 2.5. We have used nephelometer to PM 2.5 Federal Reference Method historical data (24 Hr Averages) to calculate these factors. Examples: SITEDOMINANT SOURCESCORRECTION MarysvilleWoodsmoke, Mobile 25.8 x10 4 South TacomaWoodsmoke, Mobile 24.7 x10 4 Seattle DuwamishIndustrial, Mobile 33.1 x10 4 Units are meter *  g/m 3

Slide 31 Data Sets - Comparisons

Slide 32 Neph and TEOM Discussion The direct linear relationship shown between the Nephelometer and the TEOM indicate that they both detect and measure Diesel Particulate Matter. Based on the light scattering properties of DPM, there is a different relationship (slope) than what we would see in the ambient atmosphere when more than just DPM is being measured. Particles from other sources have other light scattering properties. Diesel particles scatter much less light than the ambient PM 2.5 particles that we see in the ambient atmosphere.

Working Together for Clean Air Data Slides

Slide 34 Data Sets - Comparisons Neph Bscat Axis

Slide 35 Data Sets - Comparisons Neph Bscat Axis

Slide 36 Data Sets - Comparisons Neph Bscat Axis

Slide 37 Data Sets - Comparisons Neph Bscat Axis

Slide 38 Data Sets - Comparisons Neph Bscat Axis

Working Together for Clean Air Data Analysis

Slide 40 Aethalometer BC and TEOM

Slide 41 Aethalometer BC and Neph

Slide 42 Diesel Particulate Matter UV/BC Ratio UV/BC Ratio is a means to qualitatively differentiate between Wood Smoke type Black Carbon and Diesel type Black Carbon. Examples: Wood Smoke Darrington Site UV/BC Ratios was 1.93 Diesel UV/BC Ratio determined by this study 0.76 Darrington Wood Smoke Site Univ Wash Diesel Chamber

Slide 43 Pilot Study Preliminary Findings When monitoring fine particles from a specific diesel source, the light scattering instrument (Nephelometer) and the light absorption instrument (Aethalometer) yield different results than what we see in the ambient atmosphere. DPM Particles absorb light at 880 nm. DPM Particles scatter less light than other PM 2.5 particles when measuring with the Nephelometer. The Aethalometer BC channel does a fairly good job measuring DPM particles in terms of  g/m 3 as compared to the PM 2.5 TEOM. Combined with the knowledge of results at our wood smoke dominated sites, the UV channel does a good job identifying the difference between the wood smoke generated PM 2.5 particles and the DPM generated PM 2.5 particles

Slide 44 Aeth performance – Precision & Accuracy Aethalometer (s/n 451) Performance Verification: We co-located another Aeth (s/n 517) for a period of 2 weeks. Flow Checks Completed to eliminate Flow Inaccuracy from analysis Evaluated the instrument to instrument precision and accuracy for these two weeks which included 1 high level diesel exposure.  Conclusions:  Precision (R2) within PM 2.5 continuous monitoring standards  Bias (Accuracy) outside normal PM 2.5 monitoring standards (10%)  Unable to Calibrate Device Optics

Slide 45 Maintenance Issues Federal Reference Method (1 in 3) Use R&P 2025 Sequential Samplers Problems with Leak Checks Going into Stop Mode causes a lot of filter data retrieval and filter exchange problems R&P TEOM and/or TEOM FDMS (Continuous) Generally, R&P is very good about Service and Manuals We spend more time troubleshooting these than what is desirable, but we have had good data completeness numbers. Radiance Research Nephelometers (Continuous) Technology and Device very well understood. Service from Radiance Research lacks Met-One Beta Attenuation Monitors (Semi-Continuous) Met One Service very good Problems with Leak Checks and Flow Checks New to us, so we’re getting used to the Software Interfaces.

Slide 46 Summary 2003 Data suggests that the FDMS (Filter Dynamics Measurement System) sees aerosol that possibly volatilize from other sampling systems For example: Nephelometer uses a heated probe to knock out the moisture effects that we see in certain environmental conditions TEOM is heated to 50° C in Summer and 30° C in Winter to maintain a constant operating temperature for more consistent measurement FRM is kept near ambient by it’s internal pump, but there could be volatiles that come off the filters before they are weighed in the laboratory.

Slide 47 Summary All of the devices seem to do a credible job No one device is perfect! Determining network decisions Know the customer Cost and operation

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