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Date Permissions Signed
5-1-2018
Date of Award
Spring 2018
Document Type
Masters Thesis
Degree Name
Master of Science (MS)
Department
Geology
First Advisor
Housen, Bernard Arthur
Second Advisor
Abel, Troy D.
Third Advisor
Foreman, Brady
Abstract
Although transportation is a large source of air particulate pollution in the U.S., air quality is currently not routinely monitored on the street level or using methods that could routinely determine particulate composition. In this study, we will use biomonitoring- using biological organisms (in this case tree leaves) as sample collectors- and magnetic characterization of particulate matter (PM) to provide a simple and inexpensive alternative air quality monitoring apparatus that is at the human spatial level, can collect micron-sized particles, and can be found in closely-spaced locations, so that there is a dense area collection network. Magnetic methods such as SIRM and magnetic susceptibility have been used to gauge PM concentrations on the street level (Hoffman et al 2014, Kardel et al 2011, Lehndorff & Schwark 2004, Maher et al 2008) using biomonitors such as tree leaves. Total PM concentrations correlate well with measured magnetic values on leaf surfaces because PM contains magnetic particles sourced from iron impurities in fossil fuel vehicle exhaust, brake dust, and other vehicle sources (Sagnotti et al 2009). The geographic focus of this study is the Seattle area because it has the most traffic in the Pacific Northwest (Seattle Department of Transportation) and because a mix of residential and community activities are located near sites of industry that include manufacturing, warehousing, commercial, container shipping and support activities, concentrated in the south Seattle Duwamish Valley (Abel et al 2015). This study uses rock-magnetic methods (SIRM, magnetic hysteresis) and imaging (SEM) to characterize types of particulates, and map the spatial variation of Seattle’s air pollution. Magnetic saturation and susceptibility values for Duwamish Valley samples were higher than those of Capitol Hill samples. Coniferous leaves and deciduous leaves had similar magnetic values. The magnetic intensity of samples in a 300 mT field did not change when the field was 1 T, meaning the magnetic particles are composed of one magnetic mineral. Morphology and chemical makeup of magnetic particles varied within leaf samples, ranging from ~5-40 microns in diameter and from 0-93% Fe content. Cluster analyses determined that there are three sets of sources, but are not conclusive on whether some leaf samples have a mixture of source material on their surfaces.
Type
Text
DOI
https://doi.org/10.25710/gqy6-bn85
Publisher
Western Washington University
OCLC Number
1037276936
Subject – LCSH
Environmental monitoring--Washington (State)--Seattle; Air--Pollution--Washington (State)--Seattle--Measurement; Leaves--Effect of air pollution on--Washington (State)--Seattle; Magnetometers
Geographic Coverage
Seattle (Wash.)
Format
application/pdf
Genre/Form
masters theses
Language
English
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Creative Commons License
This work is licensed under a Creative Commons Attribution-No Derivative Works 4.0 License.
Recommended Citation
Asefa, Saba, "Biomonitoring in Seattle: Spatial Variation and Source-Determining of Airborne Pollutants in High-Traffic Areas" (2018). WWU Graduate School Collection. 690.
https://cedar.wwu.edu/wwuet/690