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Date Permissions Signed


Date of Award

Fall 2021

Document Type

Masters Thesis

Department or Program Affiliation

Environmental Science

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Montaño, Manuel D.

Second Advisor

Bauman, Jenise

Third Advisor

Rider, David A. (Materials scientist)

Fourth Advisor

Sofield, Ruth M.


Plastics are a group of materials that are mass produced for their unique properties including durability. This has led to plastics becoming a global contaminant as a bulk material and as micro and nano sized particles termed microplastics and nanoplastics (MP/NPs), respectively. As awareness to MP/NPs has grown, these contaminants are found to be ubiquitous yet the risk to environmental systems remained unclear. Toxicity studies have been performed but the transport, fate, and behavior of these contaminants remains limited by the selectivity and sensitivity of the commonly used analytical techniques. To address this deficiency, MP/NP tracers have been developed using isotopic, fluorescent, and metallic labels to enable particle detection in environmental and biological environments. Herein, I describe the application of polystyrene (PS) tracers containing internalized gold nanoparticles to investigate the transport, fate, and behavior of colloidal plastics in an estuarine system. The performed experiments investigated the PS tracers’ ability to remain suspended as a function of water chemistry and upon equilibration with sediment. Water chemistry was evaluated through varied salinity and dissolved organic carbon (DOC) concentrations while sediment was collected around Bellingham Bay and paired with synthetic fresh and marine water. Evaluation of the PS tracers was performed on an individual basis using single particle inductively coupled plasma-mass spectrometry (spICP-MS) to determine the quantity of suspended particles. The results from aqueous settling experiments found that salinity quickly increased PS tracer aggregation while DOC was a stabilizing agent at higher concentrations, as statistically evaluated using ANOVA and Tukey’s HSD. Likewise, water




microplastics, nanoplastics, polystyrene tracers, water chemistry


Western Washington University

OCLC Number


Subject – LCSH

Microplastics--Environmental testing--Washington (State)--Bellingham; Nanoparticles--Environmental testing--Washington (State)--Bellingham; Estuarine ecology--Washington (State)--Bellingham; Tracers (Chemistry)

Geographic Coverage

Bellingham (Wash.)




masters theses




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