# Presentation: 714738

## AethalometerTM Work Update

**Traffic Analysis**
**Wood Smoke Sites**
**Univ of Washington Diesel Exposure Lab**

## Objectives

**To introduce our network and project objectives**
**To communicate analysis that has been accomplished by PSCAA**
**Traffic Analysis**
**Wood Smoke Sites**
**Univ of Washington Diesel Exposure Lab**
**To encourage other agencies to try continuous Black Carbon Technologies**
**To acknowledge Aethalometer****TM**** strengths and weaknesses to further understand instrument capabilities**

## Aethalometer

**Magee Scientific Dual Channel Aethalometer****TM**
**BC Channel 880 nm**
**UV Channel 370 nm**
**Dr. Tony Hansen is the Principal Scientist**
**PM 2.5 Head at 5 LPM **

**Notes:**
What is Black Carbon?  The Aethalometer is an instrument that provides a real time readout of the concentration of Black carbon aerosol particles. These particles are emitted from all types of combustion , most notably from diesel exhaust.” Magee
We also see Wood Smoke combustion particles in our Seattle Aerosol.
What is UV Channel? Another channel in the UV spectrum that is used to further analyze the carbon aerosol to help in identification of sources in the aerosol.

## Network “Big Picture”

- “Almost Pure” Wood Smoke Darrington Site
- Sep 2004
- Marysville Wood Smoke North Site
- Jan 2005
**Lake Forest Park Wood Smoke North Site**
**Dec 2003**
**Freeway Site **
**Jan 2003**
**Industrial Site **
**Oct 2002**** **
**Urban Background Site **
**Jan 2003**
- Wood Smoke South Site
- Dec 2003

**Blue Sites denote Speciation Network**

**Network Scope**
**110 Miles**

## Monitoring Strategy

**Olive Street Freeway Site**
**225,000 vehicles per day **
**Mostly Light Duty Vehicles**
**Seattle Duwamish Industrial Site **
**58,000 vehicles per day**
**Port of Seattle – Truck Arterial**
**Seattle Beacon Hill Urban Background Site**** **
**30,000 vehicles per day**
**Neighborhood Light Duty Vehicles**

**Notes:**
Discussion about Monitoring Strategy

## Site Comparison – Traffic Indications

**Notes:**
This is the Trace for Beacon Hill, our Urban Background site in the middle of the Neighborhood on top of the hill.

## Site Comparison – Traffic Indications

**Notes:**
Now we overlay the Duwamish Trace for that same week. A little higher on average, and higher in the middle of the day during the week. It makes sense with the normal traffic patterns of these sites. We have to understand that the Duwamish is also confounded by other point source emitters in the immediate Industrial Area. 

## Site Comparison – Traffic Indications

**Notes:**
Olive Street overlayed. This is the site that is about 20 meters from I-5. 

Bottom Line: There is a difference in the patterns and levels of BC between these 3 sites. Olive Street sees the most dramatic increases of these three sites because it is so close to the Freeway.

## Traffic Data Introduction

**Traffic Data collected by WA DOT on Interstate 5 near our Freeway (Olive Street Aethalometer) site**
**Hourly Traffic Counts using a standard separation between Light Duty Vehicles and Heavy Duty Trucks**
**We compared this data to our Aethalometer BC data for a period of 2 weeks during a July Stagnation Period**

**Notes:**
Describe Olive Street Site
Go through Bullets
Talk about Confounding Effects such as Rain Scrubbing BC out of the Air, and High Wind Speed periods causing Mixing.

## Slide 10

**Notes:**
The Sunday Effect at Olive Street... Typical of this site, because it is Mobile Source Dominated.
Subtle effect of “As the highest numbers of Light Duty Vehicles are on the road, the more Stop and Go traffic builds up on I-5 near Olive Street. This causes the huffing and puffing of the diesels that dramatically raises the hourly averages of Black Carbon.
Bottom Line, The BC Channel is increasing as the traffic levels increase, and the BC Channel drops off on Sundays when the Diesel Traffic is the least. 

## Incorporating Speciation Data

| 2003 Annual Averages | BC | EC | UV | OC |
| --- | --- | --- | --- | --- |
| Industrial (Seattle Duwamish) | 1.74 | 1.32 | 1.60 | 4.21 |
| Urban BKG (Seattle Beacon Hill) | 1.02 | 0.59 | 1.05 | 2.66 |
| Freeway (Seattle Olive Street) | 1.97 | 1.44 | 1.81 | 4.42 |
|   |   |   |   |   |
|   |   |   |   |   |
| 2004 Annual Averages | BC | EC | UV | OC |
| Industrial (Seattle Duwamish) | 1.98 | 1.31 | 1.87 | 4.64 |
| Urban BKG (Seattle Beacon Hill) | 1.19 | 0.61 | 1.07 | 2.76 |
| Freeway (Seattle Olive Street) | 1.92 | 1.33 | 1.85 | 4.60 |
| Woodsmoke N (Lake Forest Park) | 1.50 | 0.87 | 1.67 | 4.66 |
| Woodsmoke S (Tacoma S. L St) | 1.54 | N/A | 1.41 | N/A |
|   |   |   |   |   |
| 2004 Quarter 4 Only | BC | EC | UV | OC |
| Woodsmoke (Darrington) | 0.95 | N/A | 1.64 | N/A |

**Notes:**
Puget Sound Air Toxics Evaluation 2002: Model – Took 1997 NATA and used Positive Matrix Factorization for additional analysis and information 
Used the Beacon Hill Monitoring Site: 
.4 ug/m3 was the estimated EC annual average value
1.4 ug/m3 of DPM was the estimate used at Beacon Hill.

## Site Comparisons Using Speciation Data

| UV-OC Regressions | R2 | Slope | Y-Intercept |
| --- | --- | --- | --- |
| Freeway | 0.50 | 1.42 | 2.0 |
| Wood Smoke North | 0.77 | 1.78 | 2.0 |

| BC-EC Regressions | R2 | Slope | Y-Intercept |
| --- | --- | --- | --- |
| Freeway | 0.84 | 0.70 | 0.1 |
| Wood Smoke North | 0.86 | 0.56 | 0.1 |

## Indicators

**BC ≠ EC ≠ DPM                        ****	**
**Harvard Research showed that the Aeth BC measurement is “directly related and equivalent to the filter based EC measurement.”**
**Thumbrule:  1.4(EC) = BC measurement. **
**UV ≠ OC ≠ WoodSmoke PM    ****	**

**Notes:**
Bottom Line is that One tool is not enough to understand what’s going on. Speciation AND Aethalometry is the approach we’ve taken in Seattle, and it is finally starting to make some sense. 

## Looking at the UV Channel

**From Dr. Tony Hansen’s Operator’s Manual and from George Allen’s Research at NESCAUM:**
**UV – BC = “Delta” or “DC”**
**“****UVPM” is Qualitative, but not Quantitative. **
**Absorption Cross Section of compounds that absorb light in the “UV” channel (370 nm) is highly variable. So this parameter “DC” has no physical engineering units.**
**In the following case, we will look at 2 sites: **
**1 Site where we don’t expect to find a “WoodSmoke” indication**
**1 Site where we DO expect to find a “WoodSmoke” indication**

## UV Channel Observations

## DC (UV-BC) Statistics : Time Resolved

|   | Industrial/Arterial Site | Wood Smoke North Site |
| --- | --- | --- |
| Mean Delta (UV – BC) | 0.009 μg/m3 | 0.554 μg/m3 |
| Time Resolved |   |   |
| 0000 to 0559 | 0.139 μg/m3 | 0.787 μg/m3 |
| 0600 to 1159 | -0.062 μg/m3 | 0.115 μg/m3 |
| 1200 to 1759 | -0.145 μg/m3 | 0.035 μg/m3 |
| 1800 to 2359 | 0.102 μg/m3 | 1.267 μg/m3 |

## DC - 30 Day Running Average

- WoodSmoke
- Season

## DC – 30 Day Running Average

## Two Ways to look at UV Channel

**DC Parameter – Defined as UV – BC. **
**A Positive Number represents a situation when Wood Smoke is Present**
**Using a regression of the data gathered in the Aethalometer, with the UV on the Y axis, and BC on the X axis, you get the slope of the curve. Defined as UV/BC.**
**Numbers Greater than 1 represent Wood Smoke is present.**
**Numbers Less than 1 represent when Diesel is present.**

## South Tacoma – Urban WoodSmoke

**Notes:**
THIS SITE HAS EXCEED THE 24HR NAAQS FOR PM 2.5.  NEED TO GET SPECIATION AT THIS SITE.

## Darrington – Rural WoodSmoke

## Duwamish – Industrial/Arterial

## Univ Washington Diesel Exposure Lab

## Summary Slide

**Dual Channel Aethalometer**
**Monitoring Strategy**
**Temporal Patterns and Traffic Data**
**Temporal Patterns and WoodSmoke Data**
**Comparisons to Speciation Data**
**DC Parameter**
**Using the Slope of the BC/UV correlation curve**
**Acknowledgements:**
**Dr. Tony Hansen, George Allen, WA DOE NW, Heidi Curtiss, Darrington High School, Univ. Washington Diesel Exposure Lab**

**Notes:**
We think these combined networks Add Great Value: Examples: -Diesel Solutions, Wood Stove Conversion Programs. 
It is essential that we incorporate the speciated data to ensure that our data sets remain of “High Quality”.