Toxicology Commons^™

Genomic Based Environmental Health Assessment: Vieques, Puerto Rico, Valeria Hernandez Talavera

Graduate Doctoral Dissertations

From 1941 to 2003, the United States Navy and North Atlantic Treaty Organization (NATO) used Vieques, Puerto Rico, for military training, which led to long-term pollution from metals, organic chemicals, explosives, and per- and polyfluoroalkyl substances (PFAS). While earlier research found these contaminants in the environment and in living organisms, their combined effects on local ecosystems remain poorly understood.

This dissertation used a Genomic-Based Environmental Health Assessment (GEHA) framework to study the ecological risks from past military pollution in Vieques. The approach combined sediment toxicity tests, chemical analysis, gene expression studies, microbial community analysis, and community-based research. The four main …

Innovating A Crustacean Embryo Toxicity (Cet) Assay For Screening Environmental Contaminants, Irina A. Polunina-Proulx

Graduate Doctoral Dissertations

Environmental pollutants can disrupt normal developmental processes, leading to neurobehavioral and developmental abnormalities. Toxicity tests are important for evaluating environmental contaminants; however, standard assays are often time- and cost-intensive and typically require large numbers of vertebrate animals. These limitations highlight the need to reduce reliance on vertebrate testing and to develop New Approach Methodologies that provide comparable results while improving efficiency and cost-effectiveness. This research utilizes a novel screening assay to evaluate developmental toxicity using Hyalella azteca. H. azteca is a freshwater amphipod widely used as a model organism for sediment toxicity in ecotoxicology, yet its embryos have been minimally …

From Sunscreen To Seafood: Tracing The Ecological And Human Health Risks Of Oxybenzone Contamination In Local Fish, Alyssa Brasko

Discovery Day - Daytona Beach

Oxybenzone (benzophenone-3) is a widely used ultraviolet (UV) filter in sunscreens, offering protection against harmful radiation but raising significant environmental concerns due to its persistence and toxicity in aquatic ecosystems. This ongoing study aims to investigate the bioaccumulation and ecological impact of oxybenzone in fish species along Florida’s Space Coast, contributing to a broader understanding of its environmental fate and potential human exposure through seafood consumption. The research will employ advanced analytical techniques, including Gas Chromatography-Mass Spectrometry (GC-MS) and High-Performance Liquid Chromatography (HPLC), to quantify oxybenzone levels in locally sourced fish. Fish samples will be obtained from the non-profit organization …

Fish Tissue Digestion And Microplastic Polymer Identification Protocol Using Open-Source Ftir Database, Shawn L. Kissinger, Vick-Ariel Privert, Jason Bystriansky, Kyle A. Grice

DePaul Discoveries

Microplastic (MP) contamination in aquatic ecosystems poses significant concerns for environmental and public health, as seafood represents a critical food source worldwide. Despite increasing evidence of MP presence in marine organisms, efficient and accessible detection methods remain essential for characterizing contamination patterns and informing regulatory frameworks. This study extracted MPs from brain, gill, intestine, liver, and muscle tissues of gilt-head bream (Sparus aurata) and European sea bass (Dicentrarchus labrax), two commercially important species from the Gulf of Cádiz, Spain, using a NaOH–HNO₃ chemical digestion protocol. Isolated particles were characterized by Fourier Transform Infrared (FTIR) spectroscopy, with …

Isolation, Quantification, And Characterization Of Microplastics In Atmospheric Fallout Across Different Areas Of Lahore, Punjab, Pakistan, Muhammad Rizwan, Aqib Javed, Muhammad Javed Islam, Kashif Riaz, Asif Bilal, Muhammad Nasir, Ayesha Ali

Journal of Bioresource Management

Microplastics have become widely dispersed in our environment, and even in the air we breathe. The present research aims at identifying and determining the amounts of microplastics present in atmospheric fallout over Lahore city, which is characterized by a large population and several manufacturing industries. In order to find out the existence of microplastics, samples of atmospheric fallout were collected from various sites across hustling municipalities of Lahore that included urbanized settlements. The analysis disclosed that there are various forms of microplastic fibers, fragments and granules indicating different sources of pollution. The identified ones varied from 114.485 µm to 2034.731 …

Environmental Mercury Alters Immune Pathways Linked To Autoimmune Risk In Mice Mirroring Humans, Maurgan Lee, Paul Stemmer, Randall Gill, Allen Rosenspire, Anil Aranha, Heather Gibson

Medical Student Research Symposium

Background and Purpose: Mercury is a pervasive environmental contaminant, and human epidemiologic studies have linked chronic low-level exposure to increased autoimmune disease-risk. Dysregulated lymphocyte activation and impaired signaling tolerance are central mechanisms in human autoimmunity. Protein phosphorylation governs lymphocyte differentiation and function, alterations in phosphoproteomic networks may represent a signature of immune disruption. This study evaluates how low dose mercury exposure modifies B and T cell abundance and intracellular signaling patterns in BALB/c and Diversity Outbred (DO) mice.

Methods: BALB/c and DO mice were exposed to low dose HgCl2 in their water for two weeks or provided standard water controls. …

The Legacy Of Lead: Lead Exposure's Harmful Effects And Its Concentration In Poc Communities, Layla Sophronia Barber

Student Theses 2015-Present

This thesis examines the disproportionate burden of lead exposure carried by low income, POC communities. The systemic nature of this problem is a symptom of a longstanding legacy of environmental injustice in the United States. Decades of federal neglect are reflected in the higher statistics of lead exposure and poisoning in predominantly black communities. While it is understood that lead exposure poses a serious threat to physical health and early cognitive development, there is a discouraging lack of urgency to remove the toxin from non-wealthy communities. The material covered by this thesis aims to identify and correct the discriminatory social …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Microplastic-Mediated Delivery Of Di-Butyl Phthalate Alters C. Elegans Lifespan And Reproductive Fidelity, Chiara Angelyn Maldonado

Presentations - 2026

•The challenge: microplastic contamination •The question: How do microplastics and chemical contaminants affect living organisms? •The follow-up: What’s next!

Polylactic Acid (Pla) Microplastic Toxicity In C. Elegans, Maria Gamez, Dana Farley, Chiara Maldonado, David Mares

Posters - 2026

• Microplastics (MPs, > 5 mm1) are an environmental pollutant that pose health risks to humans. • Primary MPs are created for direct use or plastic stocks, and secondary MPs are created when plastics in the environment break down over time. • Microplastic exposure can cause oxidative stress, metabolic disorders, immune responses, neurotoxicity, and reproductive issues2-3. • Polylactic Acid (PLA) is a biodegradable plastic used in everyday items, such as food packaging, and as a polymer in 3D printing. • PLA exposure to fish causes organ damage5 and C. elegans exposure to primary PLA MPs and UV-aged MPs reduced reproduction6-7 . …

An Investigation In The Physiological Effect Of Microplastic And Chemical Mixtures In The Body Length Of C. Elegans, Gregory Guantos, David M. Mares, Jennifer C. Harr Phd

Posters - 2026

• Microplastics (MP) are pieces of plastic less than 5 micrometers (mm). Microplastics are found in our environment and have even been found in the food humans consume, including in drinks from plastic bottles (Hu 2020).

• Di-butyl Phthalate (DBP) is a chemical known as a plasticizer commonly used in PVC applications, ink, fragrances, and adhesives

• Di-butyl Phthalate has been found to have negative effects on the physiological length of C. elegans (Xiyan 2018)

• Microplastics have similarly been found to decrease the physiological length of C. elegans (Schöpfer 2020)

• The combined effects of MPs and DBP include …

Imidacloprid Effects On The Survival And Cutaneous Microbiome Of Northern Leopard Frogs, Evelyn Margaret Osterloo

Honors Thesis

Amphibians are experiencing population declines due to habitat loss, climate change, and diseases, particularly chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. Protection from this fungal infection stems from the cutaneous microbiome. Pesticides have been shown to affect amphibians in a variety of ways, including reducing survival, locomotor performance, and accumulation in body tissues. Pesticides may also lead to changes in the cutaneous microbiome affecting amphibians who rely on these organisms as an anti-Bd defense mechanism. To investigate the effect of imidacloprid, a neonicotinoid insecticide, Northern Leopard frogs (Lithobates pipiens) were subjected to sublethal concentrations (control = …

Trophic Structure And Mercury Bioaccumulation In Walleye And Yellow Perch In The Upper And Lower Red Lake Basins, Marissa Pribyl

Biology Graduate Theses

Mercury is a persistent global contaminant that biomagnifies through aquatic food webs, with dietary and environmental factors serving as the primary drivers of accumulation in fishes. Trophic structure and methylmercury dynamics in Walleye (ogaa; Sander vitreus) and Yellow Perch (asaawens; Perca flavescens) were investigated in the Upper and Lower Red Lake basins in Red Lake, Minnesota, during 2024-2025. Diets of Walleye and Yellow Perch were assessed through stomach dissections, and tissue samples from both species were analyzed for total mercury concentrations. Additional analyses included shiners (gigoozens; Notropis spp., Hudsonius spp.) along with a variety of freshwater fish and …

Neonicotinoid Bioaccumulation In Bluegill And Bullhead Within Lake Julia And Lake Zumwalde, Jake Stuber

Journal of Earth and Life Science

Brown Bullhead Ameiurus nebulosus, Yellow Bullhead Ameiurus natalis, and Bluegill Lepomis macrochirus are unique in their stark differences. Bullhead are scaleless bottom feeders that can tolerate high pollution and low O₂ conditions. In contrast, Bluegill are scaled, aggressive nesters and are less tolerant of high pollutants or low-oxygen conditions. Among these pollutants include a class of chemicals called neonicotinoids (hereafter referred to as neonics). Neonics are a class of insecticides primarily used within agriculture and pest management. Due to the effectiveness, application has escalated on a global scale. They have been well documented by many toxicology assessments. …

Spiders In The World Of Pesticides: A Review, Jackson L. Mendillo

Williams Honors College, Honors Research Projects

Pesticides and other agrochemicals have varying effects on spiders depending on their mechanism of action and dosage, ranging from behavioral changes and ataxia, to reproductive changes and physiological stress, to lethal non-target effects. Additionally, peptide Hv1a has promising effects as a more narrow-spectrum pesticide.

The Chemistry Of Color: A Comparative Analysis Of Natural And Synthetic Dyes In Textile Application, Caitlyn Pinaga Cpht

Honors Program Theses and Research Projects

The Chemistry of Color: A Comparative Analysis of Natural and Synthetic Dyes in Textile Application examines how color functions at the intersection of chemistry, culture, and environmental responsibility. This project traces the evolution of dyeing from ancient natural pigment traditions, rooted in ecological knowledge, agricultural practices, and cultural identity, to the industrial rise of synthetic dyes, whose laboratory precision enabled unprecedented consistency, brightness, and global textile expansion. Through experimental swatch analysis, the study compares the behavior of natural dyes derived from plants and food sources with modern fiber-reactive and synthetic dye classes on a range of fibers including cotton, bamboo …

The Timing Of Pubertal Onset Affects Adults Anxiety Behavior In A Sex-Specific Manner, Evan Raubenolt

Honors Projects

This study aims to look at the relationship between the timing of pubertal onset and its long-term effects on adult anxiety behavior in rats. Though the topic of pubertal onset has been frequently discussed in developmental research, its exact effects have been inconsistent. Human models have shown that early and late maturing males are associated with a notable increase in adult anxiety behavior, while in rat models, similar sex-specific effects regarding anxiety have been demonstrated, though those studies focus on a causal relationship between exposure to stress and age of pubertal onset. This study first aims to examine that relationship …

Measuring Levels Of Ultrashort-Chain Per- And Polyfluoroalkyl Substances In Blood Collection Tubes, Alina M. Dziembowski

Discovery Undergraduate Interdisciplinary Research Internship

Per- and polyfluoroalkyl substances (PFAS) are highly persistent synthetic chemicals that are now ubiquitous in the environment. Due to PFAS stability leading to its environmental persistence, there is concern regarding potential long-term health effects as PFAS accumulation occurs in humans from dietary and inhalation exposure routes. Chronic exposure may lead to adverse effects such as fertility issues or liver damage. Although a wide range of PFAS have been found in human samples, specifically human serum, there remains data gaps for what PFAS are present in human blood. Recent innovation in detection technology has led to the ability to more accurately …

Unsaturated Fatty Acid Oil-Based Microdroplets: A Promising Novel Class Of Microdroplets, Ramiz S. Alejilat

Seton Hall University Dissertations and Theses (ETDs)

Droplet-based microfluidics has rapidly advanced numerous fields, including chemistry, biology, materials science, medicine, food science, and cosmetics. In these systems, fluorocarbon oil combined with fluorinated surfactants is the preferred medium for fluid encapsulation, offering exceptional stability and biocompatibility essential for sensitive biological and chemical processes. However, growing concerns about the environmental and biological risks associated with fluorinated chemicals have prompted a search for alternatives.

This study is the first to explore the use of unsaturated fatty acids derived from emu oil for microdroplet formation. We characterized droplet formation based on flow rates and the presence non-fluorinated surfactant at a certain …

Exposure To Pm2.5 And Aging., Daniel Chris Gomes

Electronic Theses and Dissertations

Inhalation of fine airborne particulate matter (PM_2.5) is an environmental risk factor for numerous health disorders, including cardiovascular diseases (CVD). While several studies have shown that PM_2.5 exposure can induce oxidative stress, DNA damage, and inflammation, the underlying mechanisms that translate these effects into systemic pathology remain poorly understood. Some recent studies have shown that PM_2.5 exposure can lead to telomere shortening in leukocytes, but the generality of this outcome and contribution to endothelial dysfunction has not yet been fully explored. We hypothesized that PM_2.5inhalation accelerates cellular aging and senescence in both circulating peripheral …

Effects Of Photo-Oxidized Crude Oil On Gulf Killifish Early Life Stages, Charles Campbell

LSU Master's Theses

Photo-oxidation of spilled crude oil generates polar compounds that can heighten toxicity to marine fish embryos. We investigated the effects of photo-oxidized crude oil on early life stages of Gulf killifish (Fundulus grandis) by exposing embryos under flow-through conditions to water-accommodated fractions of four oil treatments: fresh oil unexposed to either sunlight or weathering referred to as dark control (DC), a UV-light oxidized whole oil (LT), the polar fraction extracted from LT (Pol) and the remnants after extracting the Pol from LT (NP). Oil loadings of 0.38–3.00 g oil/kg water were tested. Total PAH concentrations and chemical profiles …

Exploring Potential Impacts Of Polyethylene Mesh And Polypropylene Rope Leachate On Bay Scallop (Argopecten Irradians) Survival And Growth, Katherine R. Johnson

Graduate Masters Theses

The bay scallop (Argopecten irradians), a commercially and ecologically significant bivalve along the Eastern coast of the United States, has faced severe population declines due to various anthropogenic impacts. At the same time, the proliferation of plastics, particularly in maritime industries, has introduced new threats to marine environments through both physical pollution and chemical leaching. This study aimed to assess the acute toxicological effects of leachates from two commonly used plastic products, polyethylene Netron and polypropylene rope, on A. irradians larvae. Experiments were conducted in June–July 2023 at the Nantucket Shellfish Hatchery. Leachates were prepared by incubating 0.5, …

Translation Of The Carcinogenic Dna Breakage-Repair Inhibition Mechanism For Hexavalent Chromium To Its Key Targets: Lung Epithelial Cells, Lung Tissue And Impacts On The Genome., Idoia Meaza Isusi

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death worldwide. Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread occupational and environmental exposure. Despite the known health risks, how Cr(VI) causes lung cancer remains unclear. This dissertation investigates the mechanisms of Cr(VI)-induced carcinogenesis. Cr(VI) causes DNA damage, specifically DNA double strand breaks, and inhibits homologous recombination repair, a high-fidelity repair pathway. Unrepaired DNA double strand breaks or those repaired through error-prone pathways, progress to chromosomal damage, and chromosome instability. The latter is a common characteristic of Cr(VI)-exposed cells, and a hallmark of lung cancer. Although the mechanism of Cr(VI)-induced …

Ms Environmental Biology Capstone: Evaluating Environmental Risks And Conflicts In Golf Course Landscapes, Meredith Boos

Regis University Student Publications (comprehensive collection)

1) This review investigates the relationship between pesticide use on golf courses and in agriculture to determine whether the adverse health effects documented in agricultural settings also apply to golf course environments. While the negative health effects from agricultural pesticide use are well established, golf courses use pesticides with greater frequency and intensity, suggesting a potentially higher exposure risk for both workers and players.

2) This study proposes methods to quantify pesticide bioaccumulation on golf courses and adjacent lands. We hypothesize that areas surrounding golf courses will exhibit a spatial gradient of pesticide accumulation, increasing with proximity to treated sites …

Navigating Wastewater: Minnesota Mining Wastewater Permit Challenges And Evolving Compliance Standards, Madelaine Adamich

Journal of Earth and Life Science

February of 2021 marked the beginning of Minnesota clearly establishing that groundwater qualifies as a Class 1 water in a legal battle involving United States Steel, the Minnesota Pollution Control Agency, WaterLegacy, Fond du Lac Band of Lake Superior Chippewa, the Minnesota Court of Appeals, and eventually the Minnesota Supreme Court (MNSC). Minnesota has a water classification system, as required by the federal Clean Water Act, with 7 classes of use. Class 1 waters are waters used for domestic consumption (MPCA 4, n.d.). According to Minnesota Statute § 7050.0220, the acceptable level for sulfate is 250 mg/L in Class 1 …

Evaluation Of The Dnazyme Gr5 For The Determination Of Lead Speciation In Natural Waters, Gaganprit Gill

Theses and Dissertations (Comprehensive)

This thesis explores the development and application of a DNAzyme-based biosensor designed to detect labile metal species in environmental samples. Real time and on-site monitoring of labile metal fractions would make a valuable contribution to environmental management, as these fractions are the most bioavailable and pose significant toxicity risks to aquatic organisms. Conventional methods for detecting labile metals, while effective, are often burdened by high costs, complexity, and lengthy processing times, making them less ideal for rapid and widespread environmental assessments.

The first manuscript of this thesis (chapter 2) establishes the fundamental capabilities of the Pb²⁺-specific DNAzyme GR5 …

The Relationship Between Plant Density And Microplastic Concentration In The Water In Lake Bemidji, Mn, Arian Garcia

Journal of Earth and Life Science

Microplastics, plastic particles smaller than 5 mm, are an increasing environmental threat, particularly due to their widespread distribution and toxicity. While much research has focused on larger freshwater and marine ecosystems, the presence and impacts of microplastics in smaller inland lakes remain less understood. This study investigates the relationship between plant density and microplastic concentrations in Lake Bemidji, a smaller freshwater lake. A total of 30 water samples were collected across varying vegetation conditions, ranging from open water (0%) to 90% plant coverage. Microplastics were identified and categorized into six morphological types: fibers, fragments, films, spheres/beads, and foam. The samples …

Effects Of Round-Up On The Environment, Sandra J. Marcu

Journal of Earth and Life Science

Many people around the world have used and still currently use Roundup but are unaware of the effects it has on the environment. Roundup is a spray on application weedkiller that is widely used around the world today both residentially and commercially. It enables its user to grow a garden or a field of crops with a no-tilling approach to eliminate weeds. It is a well-known and popular choice for killing weeds that has been around since the mid 1970’s (Oca, 2017). John Franz, a Monsanto scientist discovered that glyphosate (main ingredient in Roundup) was an herbicide or weedkiller, and …

Évaluation Et Caractérisation De L'Exposition Aux Fumées De Soudage Et Leurs Composantes Métalliques Lors D'Activités De Soudage Au Québec, Michèle Bouchard, Jairo Buitrago-Cortes, Naïma El Majidi, Jonathan Côté, Denis Dieme, Marc Mantha, Philippe Sarazin, Capucine Ouellet, Loïc Wingert

Rapports de recherche scientifique

Problématique et objectifs :

Les fumées de soudage sont classées comme cancérogènes chez l’humain et sont associées à un risque accru de plusieurs autres effets sur la santé des soudeurs. L’objectif général de cette recherche était d’établir la nature et le niveau d’exposition aux composantes métalliques lors d'activités de soudage chez des apprentis soudeurs au Québec, en effectuant des mesures dans différentes matrices biologiques et dans l’air lors d’un suivi longitudinal.

Méthode :Cette recherche a été réalisée dans des écoles d'apprentis soudeurs de la région de Montréal, où les techniques de soudage les plus courantes sont utilisées. Elle a …

Investigating The Acute Physiological Effects Of Effluent Crystal Violet On The Freshwater Bioindicator Daphnia Pulex, Hoang K. Ho

2024 Fall Honors Capstone Projects - Archive

This study examines the effects of acute exposure to crystal violet (CV) on the freshwater zooplankton Daphnia pulex in response to growing concerns over synthetic dyes from industrial runoff in aquatic ecosystems. The primary objective is to assess CV's impact on D. pulex's heart rate, mobility, morphology, and lethality via a series of acute exposure tests. 48-h acute toxicity (0-2000 μg/L), 48-h immobilization (0-180 μg/L), and 9-h heart rate (0-2,000 μg/L) tests were conducted using third-generation daphnids, followed by stereomicroscopic examination and statistical analysis. Results showed increasing mortality and decreasing mobility and heart rate with increasing CV concentration; the …