First Advisor

Elise F. Granek

Term of Graduation

Winter 2021

Date of Publication


Document Type


Degree Name

Doctor of Philosophy (Ph.D.) in Earth, Environment, & Society


Earth, Environment, & Society




Drugs -- Recycling -- Pacific Northwest, Chemicals -- Recycling -- Pacific Northwest, Pacific oyster -- Effect of pollution on -- Pacific Northwest, Sewage disposal plants -- Environmental aspects, Pharmacists -- Attitudes, Drugs -- Recycling -- Public opinion, Chemicals -- Recycling -- Public opinion, Alkylphenol ethoxylates, Refuse and refuse disposal



Physical Description

1 online resource (xii, 182 pages)


Anthropogenic pollution poses a threat to marine organisms and ecosystems worldwide. Common chemical pollutants that enter the marine environment include legacy contaminants, which are well known and heavily regulated or banned pollutants, and emerging contaminants, which are more recently recognized as pollutants and often lack regulatory limits for their use and discharge. Wastewater treatment plant (WWTP) effluent is a major source of various contaminants of concern, particularly pharmaceutical and personal care products (PPCPs) that are not fully removed during treatment. PPCPs exist at low concentrations in the environment and may have unknown and subtle effects on marine life. Data gaps exist on occurrence, effects, and remediation options, especially in coastal areas with low surrounding populations. Additionally, few studies focus on environmentally relevant conditions and organism, population and ecosystem level impacts.

The overarching goal of my dissertation research is to examine unexplored aspects of PPCP occurrence, effects, and pollution reduction in the Pacific Northwest. Through a field experiment, I compared PPCP accumulation in and health of Pacific oysters transplanted near WWTP outfalls and aquaculture areas in OR and WA. I also examined small-scale spatial variation in PPCP occurrence and effects along a pollution gradient near those outfalls. To identify organismal effects of PPCP mixtures on oysters, I designed and carried out a lab experiment exposing oysters to environmentally relevant concentrations of effluent from two OR coastal WWTPs. I measured growth, health, and feeding rate over a 12-week exposure period. I also compared PPCP detections and concentrations in effluent from both WWTPs and oyster tissues after effluent exposure. Lastly, I explored a potential opportunity for reducing pharmaceutical pollution with improved drug disposal practices through use and establishment of drug take-back boxes in pharmacies. I conducted surveys with pharmacy customers, interviews with pharmacists, and a focus group with other pharmacy professionals regarding drug disposal behaviors, recommendations, and obstacles.

In the field experiment, two pharmaceuticals (miconazole and virginiamycin M1) and four alkylphenols (NP1EO, NP2EO, NP and OP) were detected at low concentrations relative to other studies. Alkylphenols and virginiamycin were detected at one oyster aquaculture site indicating potential for human exposure. Oyster condition was highest at one aquaculture site, compared to other aquaculture and wastewater sites. During the 12-week lab experiment, effluent exposure had some effects on oyster growth and feeding rate, but concentration level (10%, 25%, 50%) did not drive these differences. Three alkylphenols and 30 PPCPs were detected in effluent, and four alkylphenols and 13 PPCPs were detected in oyster tissues. Despite the lack of effects observed, oysters accumulated several PPCPs in their tissues. Through customer surveys I found awareness and use of drug take-back boxes was low, but marginally improved at locations with an onsite dropbox. Pharmacist recommendations at locations with drug take-back boxes were more consistent and safe compared to locations without dropboxes. Focus group participants emphasized the importance of increasing drug take-back box locations in OR through legislative action to address improper disposal. This research fills important data gaps on PPCP occurrence in WWTP effluent and accumulation in shellfish, organismal effects of PPCP mixtures, and possible pollution reduction options.


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Persistent Identifier

Available for download on Saturday, December 18, 2021