Toxicology Commons^™

Inferring Exposure To Harmful Pseudo-Nitzschia Blooms From Ocean-To-Estuary Gradients In Domoic Acid Concentrations In Humboldt Bay Bivalves, Natasha Hope Ficzycz Winnacott

Cal Poly Humboldt theses and projects

Harmful algal blooms (HABs) result from outbreaks of any of several different species of toxin-producing phytoplankton and that can have major detrimental effects on marine ecosystems and pose severe health and economic threats to human communities. Of particular concern along the United States West Coast are HABs of pennate diatom genus Pseudo-nitzschia that produce the potent neurotoxin domoic acid (DA). The coastal ocean between Cape Mendocino, CA, and Cape Blanco, OR is a hotspot for Pseudo-nitzschia spp. HABs. Such blooms impact coastal fisheries and pose a potential threat to aquaculture operations in Humboldt Bay, California’s second largest estuary and largest …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Effects Of Microcystin-Lr On Channel Catfish (Ictalurus Punctatus) Susceptibility To Microbial Pathogens (Aeromonas Hydrophila And Edwardsiella Piscicida), Alison Marchant

Theses and Dissertations

Microcystin-LR is a hepatotoxin produced by cyanobacteria. Aeromonas hydrophila and Edwardsiella piscicida infections are leading causes of losses in market-sized channel catfish (Ictalurus punctatus). These older fish should have natural immunity in place and a predisposing factor is likely a prerequisite for these disease outbreaks. While microcystin-LR rarely causes mortality in warm-water aquaculture, we believe it may be a predisposing factor that leads to bacterial disease outbreaks during the summer months due to its ability to damage the liver. Our study investigated microcystin-LR’s effects on channel catfish susceptibility to these pathogens. We found that a sublethal dose of microcystin-LR induced …

Effects Of Titanium Dioxide Nanoparticle Injections On Tissue Function And Morphology In Goldfish (Carassius Auratus), Bryan Joel Patterson

Graduate Theses

Fish gills are sensitive to a variety of environmental factors because they regulate the exchange of oxygen and ions between the fish and the external environment. This study examined the effects of polyacrylic acid (PAA) coated titanium dioxide nanoparticle injections (TiO₂ NPs) on goldfish (Carassius auratus) over 14 days. Following the experimental period, we examined gill histological samples and looked for signs of an inflammatory response through blood glucose levels and relevant gene expression. TiO₂ injected fish developed a more robust ILCM (interlamellar cell mass) compared to the non-injected controls, which remained elevated over 14 days post injection. …

Accumulation Of Persistent Organic Pollutants In Marine Mammals: A Case Study On Cetaceans, Pinnipeds, And Sirenians, Alydia Moorhead

All HCAS Student Capstones, Theses, and Dissertations

Persistent organic pollutants (POPs) are lipophilic semi-volatile organic chemicals that present a range of challenges to marine biota, specifically marine mammals that often occupy a high trophic position in the food web. POPs have become a global problem since they have been shown to cause immunologic, teratogenic, carcinogenic, neurological, and reproductive complications in living organisms due to their resistance to biodegradation and their lipophilic nature. Marine mammals can accumulate these toxic substances through direct ingestion, trophic transfer, adsorption, and maternal offloading. They are susceptible to both bioaccumulation and biomagnification of POPs. Accumulation of POPs is affected by many variables, including …

Effects Of Heavy Metal Pollution On The Antipredator Behavior Of Orangethroat Darters (Etheostoma Spectabile), Caleb S. O'Neal

Graduate Theses/Dissertations

Heavy metal pollution can have numerous negative impacts on stream fishes, including both lethal and sublethal effects. Because of the sensitivity of fishes to toxins, they are excellent environmental indicators of stream and watershed health. The Tri-State Mining District is a Superfund site located in parts of Missouri, Kansas and Oklahoma that offers a good opportunity to study sublethal effects of heavy metal pollutants on fish behavior. I observed the antipredator behavior of Orangethroat Darters (Etheostoma spectabile) from 3 streams that varied in the abundance of heavy metal pollutants. In the lab, darters from the most polluted site …

Assessment Of Monochloramine Toxicity On Three Small Coastal Organisms, Ashley K. Le

All HCAS Student Capstones, Theses, and Dissertations

Monochloramine ( is a secondary disinfectant used by water treatment facilities to eliminate lingering bacteria in basins, filters, and pipelines. While an effective disinfectant, monochloramine can have negative effects on aquatic organisms. Organis ms affected by the chemical can include species whose environment is near to effluent sites and aquaculture facilities that use tap water lines or has water intake pipes near to effluent sites. Three species commonly found in south Florida that are lik ely exposed to MCA by effluent sites or aquaculture facilities are mosquitofish Gambusia affinis pink shrimp Farfantepenaeus duorarum and the hard clam Mercenaria mercenaria These …

Science-Based Regulation Of Pharmacological Substances In Competition Horses, Jacob Machin

Theses and Dissertations--Toxicology and Cancer Biology

Current testing methodologies within equine forensic toxicology focus on arbitrary thresholds and zero-tolerance policy. Modern analytical chemistry’s limits of detection are low enough that oftentimes femtogram-per-milliliter amounts of a substance can readily be identified in both blood and urine of a horse. For most pharmacologically relevant compounds, these concentrations have no relevance to pharmacological effect. It is therefore crucial that testing methodologies to determine appropriate thresholds and cut-offs be developed that are driven by biological activity rather than arbitrary limits of detection. This dissertation looks to address this by suggesting a system of calculated Effective Plasma Concentrations by which a …

An Evaluation Of The Susceptibility Of Goats To Larkspur Toxicosis, Kevin D. Welch, Clint A. Stonecipher, Dale R. Gardner, Benedict T. Green, Daniel Cook

Poisonous Plant Research (PPR)

Larkspurs (Delphinium spp.) are a major cause of cattle losses in western North America, whereas sheep have been shown to be resistant to larkspur toxicosis. Goats are often used as a small ruminant model to study poisonous plants, even though they can be more resistant to some poisonous plants. It is not known how susceptible goats are to the adverse effects of larkspurs. In this study, we evaluated the susceptibility of goats to larkspur toxicosis by performing a dose-response study. We dosed goats with D. barbeyi collected near Cedar City, Utah at 3.3, 4.4, 6.6, 8.8 and 10.0 g …

The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek

UCARE: Research Products

Cigarette butts are the most littered item in the world and contain over 4,000 chemicals, including the organic compound nicotine (Slaughter et al. 2011). Billions of cigarette butts are littered each year which may wash into bodies of water, impacting the local wildlife. To determine how introduced chemicals impact the environment, it is important to study its effects on indicator species. Amphibians, such as Lithobates catebeianus, act as indicator species due to their extreme sensitivity to chemical changes in its environment. The purpose of this research project was to obtain data to help determine the impact nicotine accumulation has …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Exploration Of Sonic Hedgehog Gene Expression In Fathead Minnows (Pimephales Promelas), Brooke Renee Greiner

Undergraduate Honors Theses

Pollutants, as a result of wastewater treatments, have been shown to have negative impacts on aquatic ecosystems. To better understand the possible consequences caused by effluents on ecosystems, it is important to examine ecotoxicology data. One of the most commonly used species for water quality testing is the fathead minnow, Pimephales promelas. Ecotoxicology can then be taken one step further to understand the effects of pollutants on a molecular level. Previous research had identified effluents as causes for abnormal minnow fin morphology. In order to collect additional data on development, tanks with fathead minnows were placed at the Charleston …

Ground Ingredients: Analysis Of Lead Exposure In The California Condor’S (Gymnogyps Californianus) Ground Foraging Habitat, Evan Michael Mcwreath

Graduate Theses, Dissertations, and Problem Reports (ETD)

The California Condor (Gymnogyps californianus) is a critically endangered species that reached its nadir in 1987 with a population of 27 birds in the wild. Intensive management efforts have been implemented to aid the condors’ recovery, however, anthropogenic factors, like use of lead ammunition, continue to cause fatalities in this vulnerable population. Lead toxicosis, which is responsible for approximately 40% of all condor deaths since 1992, is one of the most significant threats to condors. In birds lead poisoning leads to neurological dysfunction, reproductive impairment, immune suppression, gastrointestinal disturbance, anemia, and ultimately increased vulnerability to predation, starvation, and infection. For …

A California Without Rodenticides: Challenges For Commensal Rodent Management In The Future, Niamh Quinn, Sylvia Kenmuir, Laura Krueger

Human–Wildlife Interactions

Rodenticides are an essential tool in the integrated pest management of infestations of commensal rodents (Rattus norvegicus, R. rattus, and Mus musculus). With the introduction of Assembly Bill 1788, the California Ecosystems Protection Act of 2019, California is potentially facing a future with new restrictions on the use of anticoagulant rodenticides to manage commensal rodents in urban areas. Assembly Bill 1788 has been proposed specifically to protect predators from anticoagulant rodenticide poisoning and seeks to restrict the application of second-generation anticoagulant rodenticides (SGARs) for use in many urban and non-urban areas of California, USA. Exclusion and cultural …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Contractile Response Of Bovine Lateral Saphenous Vein To Ergotamine Tartrate Exposed To Different Concentrations Of Molecularly Imprinted Polymer, Manoj B. Kudupoje, James L. Klotz, Alexandros Yiannikouris, Karl A. Dawson, Kyle R. Mcleod, Eric S. Vanzant

Animal and Food Sciences Faculty Publications

Ergot alkaloids, in their active isomeric form, affect animal health and performance, and adsorbents are used to mitigate toxicities by reducing bioavailability. Adsorbents with high specificity (molecularly imprinted polymers: MIP) adsorb ergot alkaloids in vitro, but require evaluation for biological implications. Using ex vivo myography, synthetic polymers were evaluated for effects on the bioactivity of ergotamine tartrate (ETA). Polymers were first evaluated using isotherms. Lateral saphenous veins were collected from 17 steers for four independent studies: dose response of ETA, adsorbent dose response, validation of pre-myograph incubation conditions and MIP/ non-molecularly imprinted polymer (NIP) comparison. Norepinephrine normalized percent contractile response …

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 …

Effects Of Crude Oil On Tumor Suppressor P53 Polymorphisms In Laboratory-Exposed Atlantic Killifish, Fundulus Heteroclitus, Allison Margaret Nadler

Seton Hall University Dissertations and Theses (ETDs)

Polycyclic aromatic hydrocarbons (PAHs), constituents of crude oil, are implicated as a potent source of adverse toxicological effects on living organisms. To model the effects of PAHs in response to environmental oil spill disasters a species of killifish (Fundulus heteroclitus) was captured and exposed to crude oil in a laboratory-controlled setting. Over a period of 7 days, fish were dosed with crude oil by gavage, culled, and organs were harvested for analysis. Excitation-emission matrix spectroscopy (EEMS) of gall bladder tissue homogenates was used to verify exposure. Effects of PAHs on the p53 gene were evaluated as an indicator …

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …

Identification And Quantification Of Cyanide And Its Metabolites In Lemur Urine, Jeremy Peralta

Student Theses

Cyanide is a chemical compound that contains the monovalent groups of carbon and nitrogen. This substance is considered a rapidly acting deadly chemical. However, some animals such as lemurs consume food products that are known to contain elevated levels of cyanide without major consequences. The mechanism by which the lemur can handle this high exposure to cyanide is unknown. In this study, we developed and validated two analytical methods for the determination of cyanide and two metabolites, thiocyanate and 2-aminothiazoline-4-carboxylic acid (ATCA) in lemur urine. The method was applied to 47 authentic lemur urine samples collected from 4 different species …

Molecularly Imprinted Polymers Synthesized As Adsorbents For Ergot Alkaloids: Characterization And In Vitro And Ex Vivo Assessment Of Effects On Ergot Alkaloid Bioavailability, Manoj B. Kudupoje

Theses and Dissertations--Animal and Food Sciences

Alkaloid toxicities negatively impact livestock health and production and are of serious economic concern to animal industries. To date, few strategies have been developed to evaluate alkaloid levels in feed or to counteract alkaloid toxicities. The present research evaluated the applicability of imprinting technology to synthesize polymers that have potential to interact with ergot alkaloids and therefore reduce their bioavailability in the GIT. The studies also evaluated applicability of synthesized polymers for use in the ruminal environment using an in vitro ruminal fermentation model, and for the ability to ameliorate vasoconstriction using ex vivo myographic evaluations.

In the first experiment, …

Gonadal Intersex In Teleosts: Mechanisms, Molecular Biomarkers And Diagnostic Assays, Ahmed M.E. Abdel-Moneim Mohamed

Open Access Dissertations

Natural and synthetic estrogenic and androgenic compounds are continuously released into aquatic ecosystems. Exposure of teleost fishes to these contaminants can negatively impact sex differentiation and reproductive output. Specifically, development of gonadal intersex in gonochoristic (fixed sex) fish species has been studied extensively in relation to exposure to this class of compounds. The main objectives of this dissertation were to: 1) conduct field and laboratory studies to investigate the molecular signaling pathways behind the development of gonadal intersex; and 2) establish molecular biomarkers and assays for testing the ability of environmental pollutants to develop this condition using a battery of …

Rabbit Control: Bait Stations, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

This factsheet provides information on using bait stations for rabbit control.

Biological control agents such as the myxoma virus (myxomatosis), and rabbit haemorraghic disease virus (RHDV) or rabbit calicivirus disease, will not provide ‘magic bullets’ for reducing the impact of rabbits on agricultural production and the environment. Biological agents are more effective when they form part of an integrated approach to rabbit control. An integrated approach should use all available control options, including biological control, the use of vertebrate pesticides, shooting, and trapping programs. Control programs are most effective when they include the greatest number of properties possible (that is, …

Development Of Culturing Methods For Native Mayfly Taxa For Use In Laboratory Toxicity Testing, Kevin Nicholas Rowsey

Theses, Dissertations and Capstones

Salinity is increasing in freshwaters throughout the world due to anthropogenic impacts with the implication of the increases to biological communities only now being realized. Declining mayfly populations in Appalachian streams have generated increased interest in elevated dissolved solids in that region and their effect on benthic macroinvertebrates, particularly the sensitive Ephemeroptera taxa. Field and laboratory evaluations have indicated high sensitivity of mayflies to elevated dissolved solids. The research described herein is part of an ongoing effort to provide opportunity for toxicity testing with native mayflies in the laboratory. A successful endeavor would establish mayfly sensitivity to total dissolved solids …

The Effect Of Silver Nanoparticles On Synaptic Responses In The Lateral Giant Escape Circuit Of The Crayfish, Samantha N. Adkins

Theses, Dissertations and Capstones

The lateral giant neuron in the crayfish is a neuron that controls the reflexive escape response; the context and experience-dependent tuning of this response is critical for survival. Serotonin modulates synaptic responses in this neuron, and social experiences (stress) changes the modulatory role of serotonin. I investigated the mechanisms of induced synaptic response changes and serotonergic modulatory changes after silver nanoparticle exposure to ask if 1) contaminant induced stress changes serotonergic modulation in a manner consistent with social stress and 2) shed light on potential neurotoxic effects of widely used, but poorly understood nanomaterials. Our data show that stress induced …

Ramapough/Ford The Impact And Survival Of An Indigenous Community In The Shadow Of Ford Motor Company’S Toxic Legacy, Chuck Stead

Antioch University Dissertations & Theses

The purpose of this study was to examine the history of the Ford Motor Company’s impact upon the Ramapo Watershed of New York and New Jersey, as well as upon the Ramapough Munsi Nation, an indigenous population living there. In a 25 year span the automaker produced a record number of vehicles and dumped a massive amount of lead paint, leaving behind a toxic legacy that continues to plaque the area and its residents. The Ramapough people are not unlike many native nations living in the United States who have experienced industrial excess. This study examines the mindset that allows …

Subthreshold Toxic Effects Of Atrazine And Three Degradates On Behavior In Procambarus Clarkii, Carol B. Starkey

Theses, Dissertations and Capstones

Atrazine is among the most heavily applied pesticides worldwide, and recent evidence suggests that it may be unsafe at environmental levels. It is a known endocrine disruptor and a suggested neurotoxin. The US EPA Maximum Contaminant Level (MCL) is 3 μg/L for human ingestion and 200 μg/L for limited human exposure. Several environmentally persistent degradates have been identified, including deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HA). No MCLs have been established for these degradates, although some are suggested toxins. Thus, there remains concern for the risk associated with the presence of atrazine and its degradates in the environment. Currently little …

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 …

Determinación Del Efecto Teratogénico En El Desarrollo Del Tejido Óseo En Rattus Norvegicus Cepa Wistar, Inducido Por La Presencia De Arsénico A Concentraciones Encontradas En Aguas De Zimapán, Hidalgo, México, Mireya Quiterio-Pérez, Juan Carlos Gaytán-Oyarzún, Scott Monks, Alberto José Gordillo-Martínez, Francisco Prieto-García

Estudios científicos en el estado de Hidalgo y zonas aledañas

En el presente trabajo se evaluaron los posibles efectos teratogénicos del Arsénico (As) de las mismas concentraciones registradas en aguas de Zimapán, Hidalgo, empleando ejemplares de Rattus norvegicus de la cepa Wistar, preñadas. Las cuales se sometieron a diferentes concentraciones de Arsenato de Sodio (1887.91 mg/l, 943.95 mg/l y 0.5 mg/l), la concentración 0.5 mg/l corresponde a la registrada en agua de Zimapán, Hidalgo, así como Trióxido de Cromo (166.0 mg/l) utilizado como control positivo y Sacarosa al 5% como un control negativo. Los ejemplares se expusieron del día 7º al 15º de gestación, y se sacrificaron el día 19º …

Exploring The Sulfide Tolerance Of Ectosymbiotic Niphargus Amphipods From The Frasassi Caves, Central Italy, Jan Bauermeister, Karoline Assig, Sharmishtha Dattagupta

International Journal of Speleology

Two species of the crustacean amphipod genus Niphargus inhabit the sulfidic groundwaters of the Frasassi caves in central Italy, and both harbor filamentous, sulfide-oxidizing Thiothrix ectosymbionts. As sulfide is toxic to most aerobic organisms, it appeared possible that the ectosymbionts could help their Niphargus hosts with detoxification processes. In this study, mortality due to sulfide was compared between Niphargus individuals with ectosymbionts and individuals whose ectosymbionts had been killed by antibiotic treatment. Both Frasassi-dwelling Niphargus species revealed exceptionally high tolerances to sulfide compared to other amphipod species studied so far. Niphargus individuals without viable ectosymbionts tolerated sulfide levels exceeding those …