Toxicology Commons^™

Toxicity Of The Technology Critical Elements Germanium And Yttrium To Daphnia Magna And Hyalella Azteca And The Influence Of Toxicity Modifying Factors, Rashid Shah

Theses and Dissertations (Comprehensive)

Technology critical elements (TCEs) are increasingly used in high and green technologies but there is little aquatic toxicity data for TCEs, particularly in fresh water. The objective of this study was to investigate the toxicity of two TCEs, Ge and Y, to Daphnia magna and Hyalella azteca and to understand the role of natural organic matter and cations on toxicity modification. Testing followed standard methods. The 48 h EC50 for D. magna was 11.6 (95% CI of 9.64-13.8) mg Ge/L based on measured dissolved concentrations at test end. The addition of NOM at 10 mg DOC/L resulted in a significant …

Potential Impact Of Northern Resource Development On Aquatic Biota: Toxicity Of Chromium And Rare Earth Element Processing Reagent, So Yeon Choi

Theses and Dissertations (Comprehensive)

Chromite and rare earth element development was identified in the 2015 Canadian Federal budget as a significant opportunity, however, key data gaps exist regarding the environmental concerns related to these resource developments. Chromium is essential in the production of stainless steel, and no suitable substitute is known. Rare earth elements (REEs) are a series of metals that are composed of 15 lanthanides, as well as scandium and yttrium. Uses for REEs range from electronic devices (i.e. cell phones, computers, televisions) to magnets and controlling nuclear reactors. While commercial production of REEs signify a great economic opportunity for Canada, key data …

The Influence Of Physiological And Abiotic Factors On The Sensitivity Of The Sea Lamprey (Petromyzon Marinus) To The Lampricide 3-Trifluoromethyl-4-Nitrophenol (Tfm), Alexandra Muhametsafina

Theses and Dissertations (Comprehensive)

Invasive sea lamprey (Petromyzon marinus) in the Great Lakes are controlled using the pesticide (lampricide) 3-trifluoromethyl-4-nitrophenol (TFM), which is applied to nursery streams containing larval lamprey. The toxicity of TFM to lamprey is affected by various environmental and physiological factors, which can lead to residual lamprey that survive TFM treatment. The goal of this study was to investigate how abiotic (season and temperature) factors interacted with physiological parameters (whole body and tissue energy reserves) to influence TFM sensitivity in sea lamprey. Toxicity tests were conducted at different times of the year (spring, early and late summer, fall) and …

Forensic Markers Of Lampricide Toxicity In Oncorhynchsus Mykiss, Chris White

Theses and Dissertations (Comprehensive)

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used for decades to control invasive sea lamprey (Petromyzon marinus) populations in the Great Lakes, normally with little harm to other fish populations. However, due to the nature of lampricide treatments and the chemical properties of TFM, adverse effects to non-target fishes and non-target mortality occasionally occur. However, investigations of non-target mortality can be complex, particularly if fish deaths are not noticed immediately, due to decomposition of the carcasses. The objectives of this thesis were to expose rainbow trout (Oncorhynchsus mykiss) to TFM in order to: (i) identify forensic markers …

Testing The Underlying Chemical Principles Of The Biotic Ligand Model (Blm) To Marine Copper Systems: Measuring Copper Speciation Using Fluorescence Quenching, Tara N. Tait, James C. Mcgeer, Scott Smith

Chemistry Faculty Publications

Speciation of copper in marine systems strongly influences the ability of copper to cause toxicity. Natural organic matter (NOM) contains many binding sites which provides a protective effect on copper toxicity. The purpose of this study was to characterize copper binding with NOM using fluorescence quenching techniques. Fluorescence quenching of NOM with copper was performed on nine sea water samples. The resulting stability con- stants and binding capacities were consistent with literature values of marine NOM, show- ing strong binding with log K values from 7.64 to 10.2 and binding capacities ranging from 15 to 3110 nmole mg C ^{−1 …}

Physiological Effects Of Five Different Marine Natural Organic Matters (Noms) And Three Different Metals (Cu, Pb, Zn) On Early Life Stages Of The Blue Mussel (Mytilus Galloprovincialis), Lygia Sega Nogueira, Adalto Bianchini, Scott Smith, Marianna Basso Jorge, Rachael L. Diamond, Chris M. Wood

Chemistry Faculty Publications

Metals are present in aquatic environments as a result of natural and anthropogenic inputs, and may induce toxicity to organisms. One of the main factors that influence this toxicity in fresh water is natural organic matter (NOM) but all NOMs are not the same in this regard. In sea water, possible protection by marine NOMs is not well understood. Thus, our study isolated marine NOMs by solid-phase extraction from five different sites and characterized them by excitation-emission fluorescence analysis—one inshore (terrigenous origin), two offshore (autochthonous origin), and two intermediate in composition (indicative of a mixed origin). The physiological effects of …

Do Toxicity Modifying Factors Influence Acute Or Chronic Toxicity Of Thulium To Hyalella Azteca?, Alexandria H. Loveridge

Theses and Dissertations (Comprehensive)

The industrial demand for rare earth elements (REEs) is growing and as a result, environmental exposure is a concern. Very little is understood about the toxicity of REEs in aquatic environments. The objective of this research is to evaluate the acute and chronic toxicity of Tm and to also understand the toxicity modifying influence of dissolved organic matter (DOM) and cationic competition (Ca2+, Mg2+ and Na+). Furthermore, the aim of this study was to determine linkages between Tm bioaccumulation, growth and survival during chronic exposures. Standard methods (Environment Canada) were followed for both 96h acute and 14d chronic tests, in …

The Sublethal Physiological Effects Of Exposure To Copper And Silver Mixtures On Rainbow Trout (Oncorhynchus Mykiss), Wesley Truong

Theses and Dissertations (Comprehensive)

The mechanisms behind metal-metal interactions in freshwater environments are currently not well understood. Freshwater environments consist of many different types of metals, from those naturally present such as copper (Cu) and those that originate from anthropogenic sources like silver (Ag). Both Cu and Ag use apical sodium (Na⁺) channels for uptake into the gills of freshwater fish. In the gills, the mechanisms of Cu²⁺ and Ag⁺ toxicity appear to be similar to one another, which is by inhibiting Na⁺ /potassium (K⁺)- adenosine triphosphatase (NKA) and carbonic anhydrase (CA). Inhibition of NKA and CA …

The Influence Of Abiotic Factors On The Uptake And Elimination Of 3-Trifluoromethyl-4-Nitrophenol By Larval Sea Lamprey (Petromyzon Marinus), Benjamin Livingston Hlina

Theses and Dissertations (Comprehensive)

The backbone of sea lamprey (Petromyzon marinus) control in the Great Lakes is the use of the piscicide, 3-trifluoromethyl-4-nitrophenol (TFM), which is applied to streams containing larval sea lampreys. However, TFM effectiveness can be influenced by abiotic factors such as pH and temperature, which fluctuate daily and seasonally. The objectives of this thesis were to evaluate the influence of pH, temperature, and season on the toxicity, uptake, and elimination of TFM by larval sea lamprey. Radio-labeled TFM (¹⁴C-TFM) was used to determine how TFM uptake rates varied at different water pHs or temperatures during exposure to …

The Role Of Oxidative Stress In The Mechanisms Of Ammonia-Induced Brain Swelling And Tolerance In The Goldfish (Carassius Auratus), David F. Jones Lisser Mr.

Theses and Dissertations (Comprehensive)

Toxic build-ups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). The mechanisms of ammonia-induced brain swelling and tolerance remain elusive, but several studies have suggested a role for reactive oxygen species (ROS), which may damage proteins and lipids in the plasma membrane of astrocytes in the brain. As a result, osmotic gradients across cell membranes may be altered leading to water uptake by astrocytes and swelling. While a role for ROS has been proposed in mammals, no studies have addressed this question in …

Nickel And Copper Mixture Toxicity To Daphnia In Soft Water, Prachi Deshpande

Theses and Dissertations (Comprehensive)

Industrially important metals, such as Cu and Ni, sometimes are present at elevated concentrations in lakes, including those in the Sudbury, ON region. Although they are essential metals, their divalent-cation state (Cu²⁺ and Ni²⁺) can be toxic at high concentrations in the water. The free-ion toxicity of each of these metals has been studied in isolation, but rarely as a mixture. The economic importance of Cu²⁺ and Ni²⁺ makes them essential to study in the context of mixture toxicity. The objectives were to: (1) determine Cu and Ni mixture toxicity to Daphnia through acute LC50 …

Developing A Site Specific Understanding Of The Toxicity Of Rare Earth Elements, Cerium And Dysprosium, To Daphnia Pulex And Hyalella Azteca, Oliver Vukov

Theses and Dissertations (Comprehensive)

Rare earth elements (REEs) are a group of similarly reactive metals that are divided into two groups; the light (LREEs) and heavy (HREEs) rare earths. These metals are used in a variety of industries and are critical to the function of modern society. The demand for REEs is expected to increase and as a result new mining projects are being developed with a potential for future mining in Canada. The toxicological understanding of these metals in the aquatic environment is very limited. The objective of this research is to compare the toxicological effect of REEs to the freshwater invertebrates Daphnia …

The Establishment Of A Fibroblastic Cell Line From Yellow Perch (Perca Flavescens) And Its Potential Applications In Toxicology, Katelin W. Spiteri

Theses and Dissertations (Comprehensive)

This thesis describes the establishment, characterization and potential toxicological applications of YPF5, a yellow perch cell line. YPF5 is a fibroblastic cell line derived from the caudal fin of yellow perch. This cell line has been maintained for over 2 years. Cultures have been passaged over 60 times, and successfully cryopreserved and thawed. YPF5 is grown at room temperature in Leibovitz-15 (L-15) media, supplemented with 10% fetal bovine serum and 3% penicillin-streptomycin. The origin of YPF5 has been confirmed as Perca flavescens through “DNA Barcoding” and reaffirmed through Karyotyping (2n = 48) as per literature reported karyology for percidae including …

Effects Of Salinity And Dissolved Organic Matter On Cu Toxicity To Americamysis Bahia In Estuarine Environments, Rabia Nasir

Theses and Dissertations (Comprehensive)

As salinity increases the geochemical speciation of Cu is altered as a result of organic/inorganic complexation/competition. Such salinity changes may further challenge the osmoregulatory capabilities of euryhaline organisms. This chemical-biological interaction complicates the understanding of the impacts of Cu in estuarine waters. Dissolved organic matter (DOM) has been widely established to be an important modifier of Cu toxicity in freshwaters however its effectiveness in modulating Cu toxicity across the range of salinities that occur in estuarine conditions has not been studied in a systematic manner. Site to site differences in DOM quality with respect to the potential for toxicity mitigation …

Distribution And Elimination Of 3-Trifluoromethyl-4-Nitrophenol (Tfm) By Sea Lamprey (Petromyzon Marinus) And Non-Target, Rainbow Trout (Oncorhynchus Mykiss) And Lake Sturgeon (Acipenser Fulvescens), Michael W. Le Clair

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), has been highly successful in the control of sea lamprey (Petromyzon marinus) populations in the Great Lakes. Treatments with TFM involve applying it to streams, where it targets larval sea lamprey which live burrowed in the stream substrate. While the toxic mechanism of TFM has been elucidated, and its effects on sea lamprey described, its effects on non-target fish species such as rainbow trout (Oncorhynchus mykiss) and lake sturgeon (Acipenser fulvescens) are not as well understood. The present work demonstrated that rainbow trout show a great capacity to detoxify the lampricide using glucuronidation, when exposed to …

Does Ecosystem Disturbance Alter The Capacity Of Dissolved Organic Matter To Mitigate The Impact Of Copper To Hyalella Azteca?, Kelly Livingstone

Theses and Dissertations (Comprehensive)

The potential for aquatic ecosystem recovery as a result of dissolved organic matter (DOM) protecting against metal toxicity has become a significant area of research in environmental toxicology. It is a well-characterized relationship that DOM binds free metal ions in a concentration-dependant manner, making them unavailable for toxic action and a reduction in toxicity is seen. Less understood is source variability and how the upland terrestrial environment influences the protective quality of DOM. The aim of this study was to examine the influence of land disturbance (logging, fire, smelter emissions) on DOM quality by comparing the protective capacity of different …

The Chronic Toxicity Of Titanium Dioxide Nanoparticles To The Freshwater Amphipod Hyalella Azteca, Gurkirpal S. Malhi

Theses and Dissertations (Comprehensive)

There has been an increased use of metal-oxide nanoparticles in both commercial and consumer products. The use of these products and waste generated during manufacture may ultimately be released into the aquatic environment and the potential for these contaminants to cause impacts must be assessed. This study examines the effect of titanium dioxide (TiO₂) nanoparticles (NPs) on Hyalella azteca. Chronic toxicity exposures were conducted in 400mL of spiked test solution and contained 20 neonates. Samples collected for characterization of Ti in TiO₂ NP exposure solutions were digested using ammonium persulfate as an oxidizing agent and dissolved …

The Effect Of Cadmium Exposure On Repeat Swimming Performance And Recovery In Rainbow Trout (Oncorhynchus Mykiss), Brown Trout (Salmo Trutta) And Lake Whitefish (Coregonus Clupeaformis), Jessie L. Cunningham

Theses and Dissertations (Comprehensive)

Swim performance provides a measure of the integrated metabolic costs of sub-lethal exposure to stressors, including Cd. While the impacts to sustained swimming performance in Cd exposed fish have already been characterised, effects to repeat swimming ability have not. This thesis identifies the effects of sub-lethal waterborne Cd exposure on ionoregulatory function, repeat swimming ability, anaerobic metabolism and stress response in rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

Repeat swim trials included an initial swim to 85% of the U_crit of control fish and a recovery period …

Studies On Waterborne Cadmium Exposure To Lymnaea Stagnalis In Varying Water Qualities And The Development Of A Novel Tissue Residue Approach, Nish M. Pais

Theses and Dissertations (Comprehensive)

Recent studies have shown that the use of bioaccumulation (tissue residues) as a predictor for toxic effects for metals is a flawed concept.Adams et al. (2010) suggested a novel tissue residue approach (TRA) in which bioaccumulation in resistant organismsis related to toxic effects in sensitive organisms. The goal of this thesis was to test these assumptions in relation to Cd exposure using the great pond snail, Lymnaea stagnalis by developing and improving the understanding of Cd accumulationin aquatic invertebrates.

The relationship between Cd bioaccumulation and its toxicity was studied in L. stagnalisusing acute (96h) and chronic (one month) …

Effects Of 17Α-Ethinylestradiol (Ee2) On Reproductive Endocrine Status In Mummichog (Fundulus Heteroclitus) Under Differing Salinity And Temperature Conditions, Esteban Gillio Meina

Theses and Dissertations (Comprehensive)

Waterborne exposure to 17α-ethinylestradiol (EE₂), a synthetic estrogen, has previously been shown to decrease reproductive endocrine status in the estuarine killifish or mummichog (Fundulus heteroclitus macrolepidotus; northern subspecies). To evaluate if variations in salinity or temperature holding conditions modify the effects of EE₂ on gonad size, plasma reproductive steroid levels, and gonadal steroidogenesis, mummichog were exposed in vivo for 14 days to 0, 50 and 250 ng/L EE₂ in 0, 16 and 32 ppt salinity at 18°C and to 0 and 250 ng/L EE₂ at 10, 18 and 26°C at 16 ppt salinity. …