Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The Wabigoon River is known for an historic mercury (Hg) pollution source, caused by a chlor-alkali facility operating in the 1960s. As legacy Hg contamination continues to cause serious adverse health effects to the local communities living in the Wabigoon River region, it is imperative to undertake additional research to understand the deposition and transport of historical mercury in… more Year: 2024, 2024
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The detection of ciguatoxins (CTXs) in biological samples is challenging due to their low concentrations, the presence of various congeners, and the absence of standardized methods. This study uses high resolution mass spectrometry (HRMS) with P-CTX-3B as a reference standard. The protonated molecules ([M+H]+) were most prevalent, especially when acetonitrile/water was utilized,… more Year: 2023, 2023
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Jermilova, Una, Thesis advisor (ths): Hintelmann, Holger, Thesis advisor (ths): Kirk, Jane L, Degree committee member (dgc): Hintelmann, Holger, Degree committee member (dgc): Kirk, Jane L, Degree committee member (dgc): Landis, Wayne, Degree committee member (dgc): Buell, Mary-Claire, Degree granting institution (dgg): Trent University Abstract: <p>A significant portion (15-20%) of mercury (Hg) in the Arctic Ocean is believed to originate from Arctic rivers, such as the Mackenzie River watershed in the NWT. Recent (2005- 2020) Hg monitoring data of freshwater and fish tissue and environmental model outputs were compiled and used to develop a Bayesian Network Relative Risk model (BN-RRM), a probabilistic model capable of analyzing… more Year: 2022, 2022
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The following study measured dissolved organic carbon (DOC) and total mercury (THg) concentrations in acid sensitive lakes in the Republic of Ireland. Sixty-eight upland lakes and 48 lowland lakes were sampled for DOC; the upland lakes were additionally sampled for THg. Spatial variability of DOC was explained by regional precipitation and soil organic matter. A subset of lakes was… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>In the Wabigoon/English River system, mercury concentrations downstream from Dryden, ON, where there was a former chlor-alkali plant, remain elevated in sediments and biota. Understanding the current extent and severity of mercury contamination downstream from the former chlor-alkali plant is of great interest in furthering the clean-up of mercury within the traditional territory of… more Year: 2020, 2020
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Thawing permafrost due to increasingly warm temperatures in northern subarctic regions is releasing mercury. The consequent formation of thaw ponds in the peatland palsa valley of the Sasapimakwananisikw (SAS) river in Whapmagoostui-Kuujjuarapik, Québec may provide a pool for MMHg formation and a potential risk to aquatic and human life, if these ponds facilitate MMHg export through… more Year: 2019, 2019
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Elemental selenium has been extensively quantitatively measured in sediments; however, its physical composition is largely unknown, despite it being the dominant selenium species in some reducing environments. Here, for the first time, it is shown that small, cyclic selenium compounds can account for a quantitatively-relevant fraction of the total elemental selenium present. </p>… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>A catchment-based study was carried out at three remote acid sensitive Irish lakes to determine concentrations of Hg and POPs and to investigate the factors governing the partitioning of these pollutants in various environmental matrices. Both Hg and POPs are an environmental concern due to their ability to travel long distances via atmospheric transport and their tendency to accumulate… more Year: 2017, 2017
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The potential release of nanoparticles into aquatic environments is raising global concerns. As antimicrobials, silver nanoparticles (AgNPs) are among the most prominent form in use. Despite this, their fate, long-term toxicity, and ecological relevance have yet to be investigated largely under natural settings with seasonality and environmental complexity. To better understand the… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Baya, Pascale Anabelle, Thesis advisor (ths): Hintelmann, Holger, Degree committee member (dgc): Lamborg, Carl, Degree committee member (dgc): Hickie, Brendan, Degree committee member (dgc): Georg, Bastian, Degree granting institution (dgg): Trent University Abstract: <p>Monomethylmercury (MMHg), the most bioavailable form of mercury (Hg) and a potent neurotoxin, is present at elevated concentrations in Arctic marine mammals posing serious health threats to the local populations relying on marine food for their subsistence living. The sources of MMHg in the Arctic Ocean surface water and the role of dimethylmercury (DMHg) as a source of MMHg remain… more Year: 2015, 2015
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The increasing production and use of silver nanoparticles (AgNPs) raise concerns on environmental exposure and impact. A large scale in situ enclosure study was conducted at the Experimental Lakes Area to determine the effect of AgNPs on natural phytoplankton and zooplankton communities. This study investigated AgNPs of varying concentrations (4, 16 and 64 μg/L), dosing regimens… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p><bold>Fractionation of mercury isotopes in an aqueous environment: Chemical Oxidation</bold></p><p><italic>Dimitri Stathopoulos</italic></p><p>The study of fractionation patterns for the stable isotopes of mercury is a growing field. The potential for stable isotopes to trace mercury through the environment from pollution sources to sinks… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Name(s): Creator (cre): Webster, Eva Marie, Thesis advisor (ths): Ellis, David A, Degree committee member (dgc): Harner, Tom, Degree committee member (dgc): Hintelmann, Holger, Degree committee member (dgc): Koprivnjak, Jean-François, Degree granting institution (dgg): Trent University Abstract: <p>Ionizing organic chemicals are recognized as constituting a large fraction of the organic chemicals of commerce. Many governments internationally are engaged in the time-consuming and expensive task of chemical risk assessment for the protection of human and environmental health. There are standard models that are consistently used to supplement experimental and monitoring data in such… more Year: 2014, 2014
Member of: Trent University Graduate Thesis Collection
Abstract: <p>The fate of silver nanoparticles (AgNPs) in surface waters determines the ecological risk of this emerging contaminant. In this research, the fate of AgNPs in lake mesocosms was studied using both a continuous (i.e. drip) and one-time (i.e. plug) dosing regime. AgNPs were persistent in the tested lake environment as there was accumulation in the water column over time in drip mesocosms… more Year: 2013, 2013
Member of: Trent University Graduate Thesis Collection
Abstract: <p>Silver nanoparticles (nAg) are the largest and fastest growing class of nanomaterials, and are a concern when released into aquatic environments even at low μg L<super>-1</super. levels. Measurement at environmental levels requires extremely sensitive instrumentation, therefore this research developed two passive samplers to track the the concentration of nAg and… more Year: 2013, 2013
Member of: Trent University Graduate Thesis Collection
Abstract: <p>A novel passive sampler for mercury monitoring was prepared using organosilica sol-gel materials. It comprises a binding layer with thiol groups for mercury complexation and a porous diffusive layer through which mercury can diffuse and arrive at the binding layer. Our study demonstrated that this new sampler follows the principle of passive sampling. The mass of mercury accumulated in… more
