Toxicology Commons^™

Investigation Of Toxic Chemicals In Plant-Based Milk Alternatives, Chukwunonso A. Anakwue

Dissertations (2016-Present)

Milk is a dietary component consumed all over the world and is known to be essential for development in children. Despite all the nutritional advantages associated with milk consumption, several issues like lactose intolerance, and high lipid content, etc., negatively affects the perception of cow milk consumption, and has grown into general health concerns. Issues with cow milk consumption drove for a healthier alternative and this led to plant-based milk alternatives (PBMA). Several studies have linked consumption of these PBMAs with other negative effects such as: allergy, poor nutrient profile and the presence of other foreign chemicals. This study’s main …

Toxicity And Effects Of Tire Crumb Rubber In The Aquatic Environment, Stephanie Laplaca

All Dissertations

Plastic materials have provided innovative solutions to society’s evolving needs and challenges. Due to their durability and resistance to degradation, plastics remain in the environment for long periods of time and can therefore be transported to many environmental compartments such as water, sediment, and biota. Microplastics (MPs) have been defined as synthetic plastic particles that have at least one dimension less than 5 mm and are insoluble in water. Microrubber (MR), a recently acknowledged sub-group of MPs, has been documented in environmental samples more recently, frequently comprising a large portion of total MPs of various samples. In South Carolina specifically, …

Investigating The Developmental Impacts Of 3,3’-Dichlorobiphenyl (Pcb-11) In Zebrafish (Danio Rerio), Monika A. Roy

Doctoral Dissertations

The environmental pollutant 3,3’-dichlorobiphenyl (PCB-11) is a lower-chlorinated polychlorinated biphenyl (PCB) congener present in air and water samples. Both PCB-11 and its metabolite, 4-PCB-11-Sulfate, are detected in humans, including in pregnant women. The work conducted for this dissertation takes a developmental toxicology approach and uses zebrafish (Danio rerio) to investigate PCB-11’s potential impacts to the liver and pancreas. Chapter 1 introduces PCBs and the current knowledge gaps. Chapter 2 investigates PCB-11 interactions in short-term 4-day exposures with the Aryl hydrocarbon receptor (Ahr) pathway in both 0-20 mM individual and mixture exposures with other Ahr agonists. In Chapter 3, …

Technical Memo: Incorporating Mixture Toxicity Into Bayesian Networks To Calculate Risk To Pesticides In The Upper San Francisco Estuary., Eric J. Lawrence, Skyler R. Elmstrom, Emma E. Sharpe, Wayne G. Landis

Institute of Environmental Toxicology & Chemistry Publications

This memo presents the methods we have developed to calculate risk of mixtures of pesticides for the Upper San Francisco Estuary (USFE). We used curve fitting to estimate the exposure-response curves for each individual chemical and then the mixture. For the mixture the models were normalized for specific ECx values. In that way the curve fitting was optimized for effects that are similar to most threshold values. A Bayesian network was then built that incorporated four different pesticides and a specific mode of action. The input distributions of the pesticides were measured amounts from each of the six risk regions. …

Do Environmental Toxins Predict Violent Crimes?, Tyler Stahl

Symposium of Student Scholars

Do chemical pollutants that persistent in the environment and bioaccumulate in the body affect human health and behavior? Could these Persistent, Bioaccumulative, and Toxic (PBT) chemicals play a role in the cause of violent crimes due to deterioration of mental and cognitive functions? In the past, Mercury, a PBT chemical, has been shown in salmon to be associated with aggression. Could similar aggression occur in humans exposed to mercury through a toxic spill? Two sources of data are utilized in this analysis. The Environmental Protection Agency’s (EPA) Annual Toxic Release Inventory publishes data on toxic releases into the environment and …

Toxicology Of Chemical Stress To Monarch Butterflies (Danaus Plexippus L.), Annie Krueger

Department of Entomology: Dissertations, Theses, and Student Research

Monarch butterfly (Danaus plexippus L.) population declines have caught the attention of the country and prompted nationwide conservation initiatives. The United States Fish and Wildlife Service has identified insecticide exposure and loss of milkweed (Asclepias spp.) reproductive habitat as primary threats to the monarch. In the Midwestern US, milkweed largely occurs around cropland borders where there may be a spatial and temporal overlap of monarch larvae, insecticide usage, and fertilizer applications. In this study, the acute toxicity and sub-lethal effects on growth and diet consumption of two commonly used pyrethroid insecticides, bifenthrin and beta-cyfluthrin, were characterized …

Investigating The Effects Of Perfluorooctanoic Sulfonate (Pfos) And Ethanol On Fatty Liver Disease Using A Modified Niaaa Model., Tyler Charles Gripshover

Electronic Theses and Dissertations

Perfluoroalkyl Substances (PFAS) are a family of man-made, surfactant-like compounds that are a major environmental contaminant. A multitude of studies have indicated that PFAS are able to induce fatty liver disease and modulate lipid metabolism. However, the distinct mechanism of PFAS influence on the liver and metabolism disruption remains to be elucidated. On the other hand, it is well documented that alcohol consumption has various adverse health impacts including fatty liver disease and subsequent progression to more adverse liver states. To date, there are no published studies on whether PFAS and alcohol can jointly exacerbate fatty liver progression or interact …

In Situ Arsenic Speciation Using Surface-Enhanced Raman Spectroscopy And The Coffee Ring Effect, Valery Liamtsau

FIU Electronic Theses and Dissertations

The coffee ring effect (CRE) phenomenon is originated from the nonuniform solvent evaporation of a sessile droplet deposited onto the flat substrate. Once the evaporation starts, the droplet suspended particles move outwards by the radial flow and concentrate in the edge region of the evaporating droplet, resulting in the formation of the so-called CRE stains. In this work we have expanded the applications of the CRE from separation of particles and macromolecules to small molecules, in particular, coupled to surface-enhanced Raman spectroscopy (SERS). Herein, we have developed a theoretical framework to describe the CRE-driven separation process of small molecules, using …

Contemporary Brazilian Catholicism And Healing Practices: Notes On Environmentalism And Medicalization, Juliano F. Almeida

Journal of Global Catholicism

Anthropological studies on Brazilian Catholicism traditionally focused on popular variants of this religious practice and their relationship with the official Catholicism. Encouraged by recent anthropological perspectives, which highlight the relevance of devoting researches not only on the margins, but also on the center of social practices, this paper analyzes contemporary practices of Brazilian Catholic friars and priests on health promotion. The analysis of their publications (books that include practices and tips on health and that became best sellers etc.), as well as interviews, allows us to perceive a process of environmentalization on the contemporary Brazilian Catholicism. This process seems to …

Addressing Uncertainties Of Polychlorinated Biphenyls In Schools, Alice Fan

Master's Projects and Capstones

Despite the potential neurological health deficits resulting from polychlorinated biphenyls, there is a lack of inhalation studies and regulations to protect students and teachers who are widely exposed to PCBs in older (1950 to 1979) schools. To estimate the extent of PCB detections in Los Angeles County schools, I applied a mathematical model to estimate the range of PCB detections in schools built between 1950 and 1984. I estimate the range of 17-34% PCB detections of open schools within Los Angeles County. Next, I reviewed exposure tools provided by the US EPA to bridge the uncertainty gaps between ingestion and …

Determination Of Metals And Microplastics In Sediment From Oyster Reefs In The Mississippi Sound, Shelby Goza

Honors Theses

This research centers on the determination of metals (Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu) and microplastics (MPs) in marine sediment from oyster reefs in the Mississippi Sound Estuary. Oysters (Crassostrea virginica) are a vital part of the Gulf Coast economy, but their population has dramatically declined in recent years due to multiple stressors, including oil spills and fluctuations in salinity from flooding. Increasingly frequent flooding events also introduce high loads of MPs and sediments containing heavy metals from the Mississippi River. These pollutants can have deleterious effects on oyster biology; however, they have not been adequately …

Comparative Analysis Of Azo Dye Restriction In The International Textile Industry, Kayla Demark

Apparel Merchandising and Product Development Undergraduate Honors Theses

Azo dyes are the most used type of dye in the textile industry. Some of these dyes have the potential to be extremely toxic to both human health and the environment. While regulations of these dyes vary across the world, it is suggested that not enough is being done to protect consumers and the environment from potentially harmful azo dyes (Rawat et al., 2016). It is the responsibility of apparel companies to ensure that their products that contain azo dyes are safe for consumers.

The purpose of this study was to understand how azo dyes and their by-products are restricted …

Assessing The Role Of Chronic Arsenite Exposure In Disrupting The Egfr Signaling Axis., Christine Kim

Electronic Theses and Dissertations

Chronic arsenic exposure is a risk factor for the development of pulmonary diseases, including lung cancer, but the exact mechanism is not yet fully understood. Many previous studies have relied on acute arsenic exposure (i.e. 1-10 uM arsenic for 24 hours) to study arsenic toxicological effects. However, acute exposure does not reflect the levels or duration of arsenic associated with environmental exposure, or drinking of contaminated well water. This dissertation differentiates the effects of acute versus chronic arsenic exposures on the EGFR signaling axis and suggests possible mechanisms for chronic arsenic-induced pulmonary diseases. The EGFR is a receptor tyrosine kinase …

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

MSU Graduate Theses

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 …

Association Between Stream Impairment By Mercury And Superfund Sites In The Conterminous Usa, Karessa L. Manning

Masters Theses

Mercury is a natural element that can cause harm to the brain, heart, kidneys, lungs, and immune system, especially to fetuses developing in the womb. Many natural and anthropogenic factors contribute to mercury in the environment, such as geologic deposits, landfills, gold and silver mining operations, cement production, and atmospheric deposition. Mercury has been identified as a contaminant of concern at many National Priority List (NPL) sites, however, studies on contamination at NPL sites are often only conducted on a local level. This study was to analyze the potential connection between mercury-contaminated NPL sites and the presence of mercury impaired …

Oxidative Potential And Composition Of Fine Particulate Matter At Two Locations In Mississippi, Victoria Claire Stevens

Honors Theses

Air pollution exposure has negative health effects on individuals across the globe. Negative impacts on human health have been documented in studies following both short-term and long-term exposure to air pollution, and these adverse effects have been seen even at the lowest levels of exposure. Fine particulate matter (PM_2.5) has specifically been linked to these negative health effects. These effects come from many sources, but one large contribution to the negative health effects comes from oxidative stress. In this study, samples were collected from Hernando, MS and Gulfport, MS in September 2013 and November 2013. Black carbon (BC) …

How A Low-Cost Method For Cumulative Water-Sampling Shows Need For Improvement Of Legal Public-Contact Standards In The United States, Samuel C. Kessler

Grawemeyer Colloquium Papers

Across the world, it is estimated that 4.5 billion people live near water sources “impaired” for use or contact. Standards for human-interaction are established by international organizations such as the WHO, and legislative bodies from national to local levels with jurisdiction over the quality of our waterways to ensure public & environmental health. Standards are often assessed from “grab-samples” taken from a waterbody at a certain time, with a minimum number analyzed. Water-quality standards in the United States are enforced under the Clean Water Act (CWA) via the Environmental Protection Agency (EPA), applying to “waters of the United States” (WOTUS). …

Environmentally Marginalized Populations: The "Perfect Storm" For Infectious Disease Pandemics, Including Covid-19, Gabriella Y. Meltzer, Oyemwenosa Avenbuan, Christina Awada, Oluwakemi B. Oyetade, Tricia Blackman, Simona Kwon Drph, Mph, Esther Erdei Phd, Judith T. Zelikoff Phd

Journal of Health Disparities Research and Practice

COVID-19 has exacted a severe toll on the United States population’s physical and mental health and its effects have been felt most severely among people of color and low socioeconomic status. Using illustrative case studies, this commentary argues that in addition to COVID-19 health disparities created by psychosocial stressors such as the inability to socially distance and access quality healthcare, environmental justice communities have the additional burden of disproportionate exposure to toxic contaminants that contribute to their higher risk of COVID-19. Environmental contaminants including heavy metals and persistent organic pollutants found contaminating their nearby environments can alter the immune response, …

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 …

Effects Of Emerging Contaminants On Centrarchidae And Catostomidae In Midwestern Rivers: A Multiple Biomarker Approach, Camden Garret Nix

Masters Theses

Natural habitats of fish are gradually declining due to land use and pollution caused by industrial wastes, intensive agriculture and contamination from sewage systems. The United States has 14,780 wastewater treatment facilities that discharge effluent into navigable waters, and in some cases these discharge waters represent a considerable proportion of the water system flow. These activities make it critical to discern the effects of pollutants that are entering our waterways at a consistent rate, such as 17β-estradiol (E2) and nickel, on aquatic organisms. To determine the effects of 17β-estradiol on endocrine disruption in fish, Bluegill Sunfish (Lepomis macrochirus) …

In Vitro And In Vivo Toxicological Evaluation Of Emissions From The Fused Filament Fabrication Three-Dimensional Printing, Mariana T. Farcas

Graduate Theses, Dissertations, and Problem Reports

Fused filament fabrication (FFF), a three-dimensional (3-D) printing process, is an emerging technology that has recently gained wide popularity among both consumers and manufacturers. As filament is heated to above its glass transition temperature in a 3-D printer, a portion may undergo thermal decompostion, which releases ultrafine particles (UFP) and volatile organic compounds (VOCs) with potential adverse respiratory health effects are released into the air. This study's central hypotheses is that emissions generated during 3-D printing are toxic and exposure to these emissions induces pulmonary and systemic adverse health effects. Considering that currently, limited understanding is available on the health …