Toxicology Commons^™

Conservation Risks And Benefits Of Establishing Monarch Butterfly (Danaus Plexippus) Breeding Habitats Close To Maize And Soybean Fields In The North Central United States: A Landscape-Scale Analysis Of The Impact Of Foliar Insecticide On Nonmigratory Monarch Butterfly Populations, Tyler J. Grant, Niranjana Krishnan, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Establishing habitat in agricultural landscapes of the north central United States is critical to reversing the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Insecticide use could create population sinks and threaten recovery. Discouraging habitat establishment within a 38-m zone around crop fields is a suggested risk mitigation measure. In Story County, Iowa, United States, this mitigation would discourage habitat establishment in 84% of roadsides and 38% of noncrop land. It is unclear if the conservation benefits from establishing habitat close to crop fields outweigh suppression of population growth owing to insecticide exposure. Consequently, monarch conservation …

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). …

Impact D’Un Stress Thermique Représentatif Des Milieux De Travail Sur L’Absorption Pulmonaire Et La Toxicocinétique De Trois Solvants Organiques, Axelle Marchand, Pierre Brochu, Jessie Ménard, Sami Haddad

Rapports de recherche scientifique

Plusieurs des changements physiologiques associés à la thermorégulation peuvent influencer la cinétique des substances chimiques dans le corps humain, comme la ventilation alvéolaire et la redistribution du débit sanguin aux organes. Si certaines mesures préventives peuvent permettre de protéger les travailleurs contre les effets directs de la chaleur, elles ne permettent toutefois pas d’empêcher les processus de thermorégulation de prendre place. Une exposition concomitante à la chaleur et aux substances chimiques volatiles peut donc entraîner des variations dans l’absorption par inhalation et dans la cinétique de ces substances, biaisant ainsi l’évaluation des données de biosurveillance.

Dans cette étude, l’influence de …

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, …

Comparative Effects Of Chemical And Physical Sunscreen On Fertilization Of Purple Sea Urchins (Strongylocentrotus Purpuratus), Marilla Lippert, Maurice Codespoti Goodman, Nikki Adams

Biological Sciences

Organic compound-based “chemical” sunscreens dominate the commercial sunscreen market, but recent research has revealed the ingredients of these products are detrimental to the health of marine organisms. This revelation has led to increased popularity of mineral-based “physical” sunscreens, primarily containing zinc-oxide (ZnO), as environmentally safe alternatives. While they are marketed as environmentally safe, these claims are largely untested, and it is important to consider potential effects of ZnO-based sunscreens on the development of marine organisms. Though Zn is a necessary micronutrient in the ocean, excess Zn is released into marine environments from anthropogenic sources has negative effects on marine life. …

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 …

Pharmaceuticals In The Environment: Health Implications And Environmental Toxicity, Jessica Phillips

Wayne State University Dissertations

Approximately 2.9 billion prescriptions are written annually in the United States, with a multitude of biochemical actions, with 63151 tons used by food producing animals worldwide and an additional 55-77 million prescriptions written for companion animals. With increasing prescription and unknown toxicologic effects of many of these chemicals, zebrafish (danio rerio), an NIH approved human model, were used to model potentially health effects. Significant abnormalities were seen with extended duration metformin exposure from 4 hours post fertilization up to 5 days post fertilization, although short term metformin exposure for 24 hours at 4-5 days post fertilization did not lead to …

Amphiphilic Cell-Penetrating Peptides Containing Natural And Unnatural Amino Acids As Drug Delivery Tools And Antimicrobial Agents, David Salehi

Pharmaceutical Sciences (MS) Theses

Cell-penetrating peptides containing arginine as positively charged residues and tryptophan or diphenylalanine as hydrophobic residues were synthesized. The synthesis was accomplished through the Fmoc solid-phase peptide synthesis in the presence of HBTU and DIPEA. The side-chain protected linear peptides were cleaved from the resin and cyclized in the presence of DIC and HOAt in the solution phase overnight. MALDI-TOF mass spectrometry was used to characterize the peptides.

The cytotoxicity of the synthesized peptides was determined in CCRF-CEM (human, lymphoblast peripheral blood), and HEK-293 (human, embryonic epithelial kidney healthy) cells using the MTS assay. A concentration of 10 µM was found …

Improving The Accuracy Of Occupational Hygiene Models Used To Estimate Worker Exposure To Solvent Vapours, Spéro Abattan, Stéphane Hallé, Daniel Drolet, Ali Bahloul, Patrick Eddy Ryan, Wejden Chouchene, Carlos Castro Ruiz, Jérôme Lavoué, Maximilien Debia

Rapports de recherche scientifique

Chaque année, des travailleurs québécois subissent des effets sur leur santé après avoir été exposés à des substances chimiques, notamment à des solvants. La modélisation des expositions professionnelles occupe une place importante dans la prévention des risques. Cette recherche vise à étudier différents aspects de la modélisation pour estimer des expositions professionnelles à des vapeurs de solvants dans le but d’en améliorer la justesse de prédiction. Le travail de recherche a été effectué en deux volets. Grâce à la mise en œuvre de tests à petite échelle (volet I) et à échelle humaine (volet II), les travaux présentés dans cette …

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) …

Development And Characterization Of An Adaptable Aerosolized Methylene Diphenyl Diisocyanate Generation System, Simon Aubin, Loïc Wingert, Sébastien Gagné, Livain Breau, Jacques Lesage

Études primaires

Reactive semivolatile contaminants, such as isocyanates, can be particularly difficult to assess in occupational environments. While standard methods exist for isocyanates, there are still significant differences between the results they provide for various occupational environments or processes. This study presents the validation of a laboratory system for the generation of controlled atmospheres of isocyanates. A system consisting of different modules generated airborne methylene diphenyl diisocyanate (MDI) by nebulizing a solution into mixing and exposure chambers with control of flow rate, temperature, and relative humidity. Sampling was performed through an eight-port flow splitter that allowed only very slight within-test variability. MDI …

Survival, Growth, And Characterization Of Microbes In E-Liquids, Jessica Bunn

Master of Science in Forensic Science Directed Research Projects

Health risks associated with the use of e-cigarettes have become a concern in the last ten years, including the inhalation of volatile organic compounds, trace heavy metals, and cancer-causing agents. An additional, but poorly characterized health threat for e-liquids is the potential for bacterial contamination since the presence of pathogenic organisms can potentially cause disease from the inhalation of the microbes into the lungs. This work aims to investigate microbial growth and survival within the e-liquid matrix. Bacillus cereus T. strain and Escherichia coli were the chosen organisms for analysis of growth by absorbance, survival by viable plate counts, and …

Analysis Of Ethanol Aerosolized In An Electronic Cigarette By Headspace Gas Chromatography-Flame Ionization Detector (Gc-Fid) And Particle Size Separation, Erica R. Sales

Master of Science in Forensic Science Directed Research Projects

Electronic cigarettes (e-cigs) were designed as a healthier alternative nicotine delivery system, and involve the heating of e-liquids. These are composed of propylene glycol, vegetable glycerin, flavoring agents, and nicotine. Recently, ethanol has been identified as an unlabeled ingredient. The health consequences are currently unknown.

The purpose of this study is to quantify the amount of ethanol present in an aerosol cloud and to determine the size of the ethanol particles. A SubOx Mini-C e-cig was used. For ethanol quantification, the e-cig was attached to a Buchner Flask containing 150mL of deionized water, The system was attached to a vacuum …

Mechanisms Of Cadmium-Induced And Epidermal Growth Factor Receptor Mutation-Driven Lung Tumorigenesis, Hsuan-Pei Lin

Theses and Dissertations--Toxicology and Cancer Biology

Cadmium (Cd) is a ubiquitous pollutant in the environment and a known carcinogen for lung cancer. Cd has been shown to act as a weak mutagen, which suggests that it may exert tumorigenic effect through non-genotoxic ways, such as epigenetic mechanisms. The goal of this project is to investigate the mechanisms of Cd carcinogenesis focusing on the role of lncRNA dysregulations. The Cd-exposed cells formed significantly more colonies in soft agar, displayed cancer stem cell (CSC)-like property and formed tumors in nude mice. Mechanistically, the lncRNA microarray analysis revealed that chronic Cd exposure dysregulates lncRNA expressions. Q-PCR analysis confirmed the …

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 …

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 (ETD)

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 …

Maternal Engineered Nanomaterial Inhalation Exposure: Cardiac Molecular Reprogramming In Progeny Through Epigenetic And Epitranscriptomic Mechanisms, Amina Kunovac

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: Nano-titanium dioxide (TiO₂), a prominently utilized engineered nanomaterial (ENM), is being employed for its physiochemical properties in several fields including the food industry, manufacturing, and biomedicine. As the prevalence of this ENM, and other particulate matter grows, so does the concern for antagonistic consequences on long-term heart function in vulnerable populations, which until now have not been investigated. Due to the reliance of the heart on the ATP generating capacity of mitochondria for contraction, understanding the role of mitochondrial bioenergetics and structure is pivotal in understanding the repercussions of particulate matter exposure during gestation. As the mass …

Quantitation Of Fentanyl And Metabolites From Blow Fly Tissue And Development Effects Of Fentanyl On Lucilia Sericata, Joseph Allen Cox

Graduate Theses, Dissertations, and Problem Reports (ETD)

Death investigations often involve collaborative work between different forensic disciplines, especially with regards to pathology, toxicology, and entomology. This dissertation investigates the effects of designer opioids on the development of blow fly (Lucilia sericata) larvae and the ability to detect and quantify the drugs and/or metabolites present in each stage of the fly’s life cycle. Therefore, we evaluated human tissue fortified with fentanyl at four treatment concentrations, and blow fly larvae were placed to feed on the drug infused tissue. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method was developed, validated, and applied to extract …

Occupational Exposure To Antineoplastic Drugs: What About Hospital Sanitation Personnel?, France Labrèche, Capucine Ouellet, Brigitte Roberge, Nicolas J Caron, Ahmed Yennek, Jean-François Bussières

Études primaires

Objective

Occupational exposure to antineoplastic drugs (ANPs) occurs mainly through dermal contact. Our study was set up to assess the potential exposure of hospital sanitation (HS) personnel, for whom almost no data are available, through contamination of surfaces they regularly touch.

Methods

In the oncology departments of two hospitals around Montreal, surface wipe samples of 120–2000 cm² were taken at 10 sites cleaned by the HS personnel and five other sites frequently touched by nursing and pharmacy personnel. A few hand wipe samples were collected to explore skin contamination. Wipes were analyzed by ultra-performance liquid chromatography tandem–mass spectrometry for …

The Effects Of Fluoride On Macrophage Thp-1 Cell Apoptosis, Jessica Heims

Honors Program Theses

Fluoride is an earthly mineral that occurs naturally both in the sedimentary earth as well as in the human body. The main biological function of fluoride in the human body is to enhance bone structure, as well as prevent the decay of teeth. This mineral has been used by dentists and public health officials to artificially introduce an extra layer of protection through the means of fluoride-enriched public water supplies and toothpastes. By using extra levels of fluoride, dentists have been able to help patients prevent future cavities and dental diseases. Although most dentists highly encourage strategic consumption of these …