Ellis, David

In this thesis, aerosolization was studied as a possible means of water remediation for several environmentally relevant pharmaceutical pollutants, known for their persistence in wastewater effluent and potable water sources. Seven different pharmaceutical compounds and a well-known plasticizer were all shown to decrease considerably in concentration in aerosol that was produced and subsequently collected within a short time span. Strong evidence is presented that an enhanced rate of partitioning into the gas phase at the air-water interface of water droplets exists for every compound tested relative to that occurring in bulk solution. UV photolysis in aerosols was also explored and shown for sulfamethoxazole to be at least an order of magnitude faster in aerosols then in bulk solution. The implications towards both the environmental fate, and removal of these compounds from water sources is discussed.

Author Keywords: Aerosols, Air-water partitioning, Pharmaceuticals, Photolysis, Sulfamethoxazole

Cis-isomers of the cytokinin plant hormone family are thought to have low activity or impact on plant growth and development. Mutants with independent silencing of the pathway leading to cis-CK (cis-cytokinin) were investigated at the phenotype and metabolite levels. Phenotypic deviations were noted in trichome development, fresh weight, rosette diameter, number of non-rosette leaves, shoot height, delayed flowering, flower number, and carotenoids. Exploratory metabolomic analysis detected a number of metabolite features that have been associated with CK, auxin, and ABA (abscisic acid) activity. Evidence from both phenotype and metabolomic analysis support the hypothesis that cis-CK production is biologically important for plant growth and development.

Author Keywords: arabidopsis, cytokinin, IPT, metabolmics

In this thesis, water mass distribution of dissolved organic matter (DOM) characteristics (i.e. molecular weight, fluorescent components, thiols and humic substances concentration) was observed in the Arctic Ocean. For the first time, DOM molecular weight (MW) in Beaufort Sea was assessed using asymmetrical flow field-flow fractionation, as well as the first monitoring of thiols and humic substances (HS) using cathodic stripping voltammetry (CSV) in the Arctic Ocean. Based on fluorescence property, DOM characterization was carried out using parallel factor analysis – excitation-emission matrices. Pacific winter waters in the Canada Basin showed higher MW DOM associated with higher fluorescence intensity. High HS was associated with the Arctic outflow waters in top 300 m of the Canadian Arctic Archipelago. Interestingly, maximum thiol concentration was associated with the subsurface chlorophyll-a maximum at most sites, but not universal along the study area. Comparable distributions of CSV-based HS and humic-like fluorescent components suggest similar sources/ processes in the Arctic Ocean. The findings in this thesis suggested DOM characteristics could be used as fingerprints in tracing water masses in the Arctic Ocean.

Author Keywords: Asymmetrical flow field-flow fractionation, Cathodic stripping voltammetry, DOM, Metal-binding ligands, Molecular weight, PARAFAC-EEMs

This study focused on detecting 22 target anti-estrogenic and anti-androgenic compounds in surface waters influenced by both discharges of municipal wastewater and agricultural runoff in Canada and Argentina. Polar organic chemical integrative samplers (POCIS) were used to monitor the target compounds in surface waters. The removals of the target compounds in a municipal wastewater treatment plant (WWTP) in Canada were also evaluated. In both Canada and Argentina pesticides with potential anti-estrogenic and anti-androgenic activities were detected in the surface waters. The highest concentrations were found in Argentina (up to 1010 ng L-1) in areas impacted by heavy agricultural practices. Cyproterone acetate and bicalutamide were the only two anti-cancer drugs detected only at the Canadian study site, the Speed River, ON. In the Guelph WWTP, that discharges into the Speed River, these target compounds were not all efficiently removed (>70%) during treatment. Overall, this study provides insight to possible anti-estrogenic and anti-androgenic compounds that may be contributing to endocrine disrupting activities in surface waters.

Author Keywords: Anti-androgens, Anti-estrogens, Cancer Therapy Drugs, Current use pesticides, Pharmaceuticals and Personal Care Products, Polar Organic Chemical Integrative Samplers