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Full-Text Articles in Toxicology

Bioaccumulation Of As, Cd, Cr, Cu, Pb, Zn In Ambrosia Artemisiifolia L. In The Polluted Area By Enterprise For The Production And Processing Of Batteries, Ryzhenko Nataliia, El Amrani Abdelhak, Michelle Giltrap, Furong Tian, Volodymyr Laptev Jul 2022

Bioaccumulation Of As, Cd, Cr, Cu, Pb, Zn In Ambrosia Artemisiifolia L. In The Polluted Area By Enterprise For The Production And Processing Of Batteries, Ryzhenko Nataliia, El Amrani Abdelhak, Michelle Giltrap, Furong Tian, Volodymyr Laptev

Articles

In this paper, the concentration of As, Cd, Cr, Cu, Pb, Zn was investigated in soil and Ambrosia artemisiifolia L. sampling from polluted cite near the enterprises for the production and processing of batteries in the city of Dnipro in Ukraine. The obtained results of the study provided to assess plants regarding bio-monitoring and phytoremediation. Although Ambrosia artemisiifolia L. is a weed that causes serious allergic reactions in humans, this species can also have a high bioaccumulative capacity regarding metals. The metals’ concentration in roots was scientifically higher than in inflorescence part. Zn and Cu had the highest …


Towards The Determination Of Estrone And 17Β-Estradiol In Dairy Cattle Waste Using Solid Phase And Stir Bar Sorptive Extractions With Liquid Chromatography-Mass Spectrometry And Gas Chromatography-Mass Spectrometry, Pallavi Ragi May 2022

Towards The Determination Of Estrone And 17Β-Estradiol In Dairy Cattle Waste Using Solid Phase And Stir Bar Sorptive Extractions With Liquid Chromatography-Mass Spectrometry And Gas Chromatography-Mass Spectrometry, Pallavi Ragi

Masters Theses & Specialist Projects

Steroidal hormones are naturally produced as a part of many physiological processes and are excreted in the urine and feces of animals and humans. Farm animals in concentrated animal feeding operations (CAFOs) are routinely implanted with synthetic and natural hormones to enhance growth and production, contributing significantly to environmental steroid hormone contamination. Every year around 49 tons of estrogens are generated by livestock waste in the United States alone. Due to rainfall and runoff, these steroid hormones reach the environment when animal waste is applied as manure. Studies show that estrogens and other steroidal hormones present in the surface waters …


The Sublethal Response Of Cambarus Sp. To Acute Low Dose Herbicide Exposure Evidenced By A Change In Ggt Levels And Apoptosis, Amelia Wickham Apr 2022

The Sublethal Response Of Cambarus Sp. To Acute Low Dose Herbicide Exposure Evidenced By A Change In Ggt Levels And Apoptosis, Amelia Wickham

Senior Honors Theses

Following application, herbicidal runoff can collect in freshwater ecosystems, briefly exposing non-target organisms. As biological indicators, crayfish serve as models to assess freshwater health. Chemically stressed crayfish form reactive oxygen species (ROS) which are neutralized by the glutathione pathway. As glutathione depletes, γ-glutamyl-transferase (GGT) upregulates to increase glutathione formation. High oxidative stress lowers glutathione levels and subsequent apoptosis occurs. For this acute study, crayfish were exposed to 5ppb and 50ppb of atrazine, glyphosate, and 2,4-D. Herbicide exposures were expected to induce higher GGT production, increased oxidative stress, and increased apoptosis. Instead, GGT and apoptosis predominately decreased relative to the control. …


The Unexpected Influence On Talent From Air Pollution, Singapore Management University Mar 2022

The Unexpected Influence On Talent From Air Pollution, Singapore Management University

Perspectives@SMU

CUHK research shows air pollution in China is driving educated and skilled company executives to move away from highly polluted areas, hampering the performance of firms located there


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 Oct 2021

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. …


Toxicology Of Chemical Stress To Monarch Butterflies (Danaus Plexippus L.), Annie Krueger Aug 2021

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 …


In Situ Arsenic Speciation Using Surface-Enhanced Raman Spectroscopy And The Coffee Ring Effect, Valery Liamtsau Jun 2021

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 …


Nutrient Concentration For Cyanotoxins At Turnbull (Proposal), Mori Williams Nov 2020

Nutrient Concentration For Cyanotoxins At Turnbull (Proposal), Mori Williams

2020 McNair Scholar Collection

The purpose of this study is to analyze the concentration of microcystins from cyanobacteria along with factors that increase the likelihood of microcystins found in water systems at the Turnbull National Wildlife Refuge (TNWR) near Cheney, Washington. Cyanobacteria are oxygen-producing bacteria that use sunlight as an energy source to convert CO2 into biomass. This bacterium has been around for around 3 billion years. However, in recent years, cyanobacteria have been a major issue in drinking water and aquatic ecosystems due to eutrophication, rising CO2 levels, and global warming (Huisman et al). Due to anthropogenic sources such as agricultural run-off and …


David S. Miller: Scientist, Mentor, Friend--A Tribute And Thank You, Björn Bauer, J. Larry Renfro, Karl J. Karnaky, Rosalinde Masereeuw, Gert Fricker, Ron E. Cannon, Anika M. S. Hartz Sep 2020

David S. Miller: Scientist, Mentor, Friend--A Tribute And Thank You, Björn Bauer, J. Larry Renfro, Karl J. Karnaky, Rosalinde Masereeuw, Gert Fricker, Ron E. Cannon, Anika M. S. Hartz

Pharmaceutical Sciences Faculty Publications

David S. Miller was Acting Scientific Director of the Division of Intramural Research at the National Institute of Environmental Health Sciences, National Institutes of Health, and Head of the Intracellular Regulation Group in the Laboratory of Toxicology and Pharmacology before he retired in 2016. David received his Ph.D. in biochemistry from the University of Maine in 1973. David was a Group Leader at the Michigan Cancer Foundation before joining the NIEHS in 1985. His research covered a wide range from renal excretory transport mechanisms to regulation of transporters at the blood-CSF and blood-brain barriers, from fish, amphibians and birds to …


Single-Use Plastics And Covid-19: Scientific Evidence And Environmental Regulations, Robert C. Hale, Bk Song Jun 2020

Single-Use Plastics And Covid-19: Scientific Evidence And Environmental Regulations, Robert C. Hale, Bk Song

VIMS Articles

Waste plastics are a serious and growing environmental problem. Less than 10% of plastics are recycled, with most discarded in landfills, incinerated, or simply abandoned.1 Single-use plastics constitute about half of plastic waste. While most plastics are used and initially disposed of on land, much eventually enters aquatic ecosystems.2 Wildlife mortalities result from encounters (e.g., ingestion and entanglement) with large debris, including plastic bags. Such bags are excluded from many recycling programs, as they can entangle machinery. Most plastics do not readily biodegrade in the environment. However, they can be embrittled by UV exposure and fragment into microplastics (mm) and …


The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek Apr 2020

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 …


Comparing Statistical Analyses To Estimate Thresholds In Ecotoxicology, Marcos Krull Apr 2020

Comparing Statistical Analyses To Estimate Thresholds In Ecotoxicology, Marcos Krull

VIMS Articles

Different methods are used in ecotoxicology to estimate thresholds in survival data. This paper uses Monte Carlo simulations to evaluate the accuracy of three methods (maximum likelihood (MLE) and Markov Chain Monte Carlo estimates (Bayesian) of the no-effect concentration (NEC) model and Piecewise regression) in estimating true and apparent thresholds in survival experiments with datasets having different slopes, background mortalities, and experimental designs. Datasets were generated with models that include a threshold parameter (NEC) or not (log-logistic). Accuracy was estimated using root-mean square errors (RMSEs), and RMSE ratios were used to estimate the relative improvement in accuracy by each design …


Development Of A Hybrid Bayesian Network Model For Predicting Acute Fish Toxicity Using Multiple Lines Of Evidence, S. Jannicke Moe, Anders L. Madsen, Kristin A. Connors, Jane M. Rawlings, Scott E. Belanger, Wayne G. Landis, Raoul Wolf, Adam D. Lillicrap Feb 2020

Development Of A Hybrid Bayesian Network Model For Predicting Acute Fish Toxicity Using Multiple Lines Of Evidence, S. Jannicke Moe, Anders L. Madsen, Kristin A. Connors, Jane M. Rawlings, Scott E. Belanger, Wayne G. Landis, Raoul Wolf, Adam D. Lillicrap

IETC Publications

A hybrid Bayesian network (BN) was developed for predicting the acute toxicity of chemicals to fish, using data from fish embryo toxicity (FET) testing in combination with other information. This model can support the use of FET data in a Weight-of-Evidence (WOE) approach for replacing the use of juvenile fish. The BN predicted correct toxicity intervals for 69%–80% of the tested substances. The model was most sensitive to components quantified by toxicity data, and least sensitive to components quantified by expert knowledge. The model is publicly available through a web interface. Further development of this model should include additional lines …


Worker Exposure To Flame Retardants In Manufacturing, Construction And Service Industries, C. Fairfield Estill, J. Slone, A. Mayer, I-C Chen, Mark J. La Guardia Feb 2020

Worker Exposure To Flame Retardants In Manufacturing, Construction And Service Industries, C. Fairfield Estill, J. Slone, A. Mayer, I-C Chen, Mark J. La Guardia

VIMS Articles

Workers in several industries are occupationally exposed to flame retardants. This study characterizes flame retardant exposure for nine industries through air and hand wipe measures for 105 workers. Specifically, we analyzed 24 analytes from three chemical classes: organophosphate flame retardants (OFRs), polybrominated diphenyl ethers (PBDEs), and non-PBDE brominated flame retardants (NPBFRs). The industries were: carpet installation, chemical manufacturing, foam manufacturing, electronic scrap, gymnastics, rigid board installation, nail salons, roofing, and spray polyurethane foam. Workers wore personal air samplers for two entire workdays and provided hand wipe samples before and after the second work day. Bulk products were also analyzed. The …


Qualitative Approach To Comparative Exposure In Alternatives Assessment, William Greggs, Thomas Burns, Peter Egeghy, Michelle R. Embry, Peter Fantke, Bonnie Gaborek, Lauren Heine, Olivier Jolliet, Carolyn Lee, Derek Muir, Kathy Plotzke, Joseph Rinkevich, Neha Sunger, Jennifer Y. Tanir, Margaret Whittaker Nov 2019

Qualitative Approach To Comparative Exposure In Alternatives Assessment, William Greggs, Thomas Burns, Peter Egeghy, Michelle R. Embry, Peter Fantke, Bonnie Gaborek, Lauren Heine, Olivier Jolliet, Carolyn Lee, Derek Muir, Kathy Plotzke, Joseph Rinkevich, Neha Sunger, Jennifer Y. Tanir, Margaret Whittaker

Public Health Sciences Faculty Publications

Most alternatives assessments (AAs) published to date are largely hazard-based rankings, thereby ignoring potential differences in human and/or ecosystem exposures; as such, they may not represent a fully informed consideration of the advantages and disadvantages of possible alternatives. Building on the 2014 US National Academy of Sciences recommendations to improve AA decisions by including comparative exposure assessment into AAs, the Health and Environmental Sciences Institute's (HESI) Sustainable Chemical Alternatives Technical Committee, which comprises scientists from academia, industry, government, and nonprofit organizations, developed a qualitative comparative exposure approach. Conducting such a comparison can screen for alternatives that are expected to have …


Hexavalent Chromium-Induced Cytotoxicity And Mutagenicity: A Study Of Protection By Ascorbic Acid And Epigallocatechin Gallate, Timothy P. Mayotte Jul 2019

Hexavalent Chromium-Induced Cytotoxicity And Mutagenicity: A Study Of Protection By Ascorbic Acid And Epigallocatechin Gallate, Timothy P. Mayotte

Honors Program Projects

Hexavalent chromium, or Cr(VI), is a potent oxidizer and known carcinogen, that is found at varying levels in the water sources of more than 200 million Americans. However, the exact mechanism of carcinogenicity remains unknown, and though the government currently regulates total chromium levels, they have yet to determine a permissible exposure limit for Cr(VI). Moreover, there is currently no preventative treatment for Cr(VI). Because of Cr(VI)’s strong oxidative power, we hypothesized that it causes DNA mutation and cell death via oxidation and that antioxidants could prevent this from occurring. To test this, we first assessed the viability of human …


Residues Of Thiamethoxam And Mefenoxam In Vegetative And Floral Tissue Of Soybean At The Early Reproductive Stage Resulting From Seed Treatments, Carolina Camargo, Daniel D. Snow, Sathaporn Onanong, Thomas Hunt, Blair Siegfried Jan 2019

Residues Of Thiamethoxam And Mefenoxam In Vegetative And Floral Tissue Of Soybean At The Early Reproductive Stage Resulting From Seed Treatments, Carolina Camargo, Daniel D. Snow, Sathaporn Onanong, Thomas Hunt, Blair Siegfried

Department of Entomology: Faculty Publications

Thiamethoxam with mefenoxam is the most widely used neonicotinoid insecticide/fungicide mixture applied to soybean (Glycine max [L]) as seed treatments. Based on the systemic nature of thiamethoxam and mefenoxam, residues of this insecticide/fungicide mixture may be present in soybean vegetative and floral tissue and negatively impact beneficial insects. Although neonicotinoids are often applied in combination with systemic fungicides, the research on ecological risks of neonicotinoids has been focused on the analysis of these compounds without considering their interaction with other agrochemicals. The objective of this study was to identify the concentration of thiamethoxam and mefenoxam in soybean flowers and …


Aptamer-Based Assay For Detection Of Ochratoxin A, Amanda Nicole Bartley Nov 2018

Aptamer-Based Assay For Detection Of Ochratoxin A, Amanda Nicole Bartley

FIU Electronic Theses and Dissertations

Ochratoxin A (OTA) is a potent mycotoxin found in a wide range of agricultural products that has been linked to mitochondrial damage and renal disease. The standard methods for OTA analysis currently rely on the use of high-performance liquid chromatography (HPLC) coupled to fluorescence detection or mass spectrometry. Toward a highthroughput analysis of OTA, a single-stranded DNA aptamer, modified with a fluorophore, coupled to a complementary sequence, modified with a FRET-based quencher that dissociates in the presence of the target toxin, is proposed. In order to integrate “target trapping,” aptamer immobilization methods were explored to mediate interference issues. Assays were …


Development And Application Of Aquatic Toxicology Studies For The Assessment Of Impacts Due To Chemical Stressors Using Non-Standard Indigenous Organisms, Abraham Jeffrey Smith Apr 2018

Development And Application Of Aquatic Toxicology Studies For The Assessment Of Impacts Due To Chemical Stressors Using Non-Standard Indigenous Organisms, Abraham Jeffrey Smith

FIU Electronic Theses and Dissertations

Research in the multidisciplinary science of ecotoxicology is crucial to assess injuries to ecosystem resources from chemical spills or other stressors used to support environmental decision-making. Established guidelines recommend the use of non-standard native species in toxicity investigations. This work focused on the use of native species for aquatic toxicity assessment to make more relevant conclusions on the potential for adverse biological effects to occur as a result to single chemical exposures or exposures to a complex mixture like oil. We apply these studies to investigate petroleum product impacts from the Deepwater Horizon incident and concerns for metal toxicity in …


Importance Of Growth Rate On Hg And Pcb Bioaccumulation In Fish, Jiajia Li, G. Douglas Haffner, Gordon Paterson, David M. Walters, Michael D. Burtnyk, Ken G. Drouillard Jan 2018

Importance Of Growth Rate On Hg And Pcb Bioaccumulation In Fish, Jiajia Li, G. Douglas Haffner, Gordon Paterson, David M. Walters, Michael D. Burtnyk, Ken G. Drouillard

Great Lakes Institute for Environmental Research Publications

To evaluate the effect of fish growth on mercury (Hg) and polychlorinated biphenyls (PCBs) bioaccumulation, a non-steady state toxicokinetic model, combined with a Wisconsin bioenergetics model, was developed to simulate Hg and PCB bioaccumulation in Bluegill (Lepomis macrochirus). The model was validated by comparing observed versus predicted Hg and PCB 180 concentrations across 5 age classes from five different waterbodies across North America. The non-steady state model generated accurate predictions for Hg and PCB bioaccumulation in three of five waterbodies: Apsey, Sharbot and Stonelick Lake. The poor performance of the model for the Detroit River and Lake Hartwell, …


Regulation Of Radioactive Fracking Waste, Elizabeth Ann Glass Geltman, Nichole Leclair Jan 2018

Regulation Of Radioactive Fracking Waste, Elizabeth Ann Glass Geltman, Nichole Leclair

Publications and Research

Natural gas extracted form shale reached record production totals in 2015 in the United States and the US Energy Information Administration (EIA) forecasts natural gas production will continue to increase. Wastes from shale gas extraction can contain the radioactive isotopes radium-226 (Ra-226) and radium-228 (Ra-228), which decay further into radon (Rn). Exposure to radon, a form of naturally occurring radioactive materials (NORM), is the leading cause of lung cancer in the United States, after smoking. This article explores how states handle the disposal of technologically enhanced naturally occurring radioactive materials (TENORM) and/or NORM waste from oil and gas operations to …


Fate Of Methoprene In Temperate Salt Marsh Ditches Following Aerial Applications, David J. Tonjes, Anne E. Mcelroy, Robin K. Barnes, Dominick V. Ninivaggi, Walter Dawydiak, Gregory T. Greene, Bruce J. Brownawell Jan 2018

Fate Of Methoprene In Temperate Salt Marsh Ditches Following Aerial Applications, David J. Tonjes, Anne E. Mcelroy, Robin K. Barnes, Dominick V. Ninivaggi, Walter Dawydiak, Gregory T. Greene, Bruce J. Brownawell

Technology & Society Faculty Publications

Aerial applications of liquid methoprene are used in salt marshes to control mosquitoes by preventing adult emergence. Despite concern about toxicity to non-target organisms, little is known about environmental concentrations after applications, nor methoprene's persistence in salt marsh environments. Aqueous and sediment samples were collected from two marshes receiving weekly applications. Aqueous samples were collected as early as 30 minutes after applications and as long as nine days afterwards; sediment samples were taken within hours of application and as long as 19 days post-application. Use of time-of-flight liquid chromatography – mass spectral analysis allowed for ultra low detection limits (0.5 …


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 Dec 2017

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 …


The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub Jun 2017

The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub

FIU Electronic Theses and Dissertations

Cancer is the second leading cause of mortality in the United States and the World, therefore, early effective prevention, diagnosis, and therapy is needed. Estrogens play a major role in the initiation and progression of breast cancer. Elevated lifetime exposure to estrogens is associated with an increased risk of developing breast cancer. Estrogens through influencing mitochondria contribute to estrogen induced breast carcinogenesis; however, the exact mitochondrial mechanisms underlying the estrogen carcinogenic effect in breast tissue are not clearly understood. For this dissertation, the mitotoxic and cytotoxic effects of triphenylphosphonium cation (TPP) and Origanum majorana organic extract (OME) as well as …


Growth And Survival Of Salamanders Exposed To Different Formulations Of Glyphosate-Based Herbicide, Jessica Johnson Jun 2017

Growth And Survival Of Salamanders Exposed To Different Formulations Of Glyphosate-Based Herbicide, Jessica Johnson

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations have been experiencing rapid declines worldwide in the past few decades. There are many proposed causations, including the use of agricultural chemicals such as herbicides. Glyphosate based herbicides are one of the most widely used herbicides. This study looks at the effects of different brands of glyphosate-based herbicides, including those intended for aquatic use, on the survival and growth of axolotl salamander larvae. Out of four brands of glyphosate herbicide (Aquamaster, Aquaneat, Helosate plus, and Roundup Pro), the survival rates of Roundup Pro were the lowest. Most mortality occurred between the 3 mg/L and 6 mg/L concentrations, during …


Evaluation Of Perfluorohexane Sulfonate (Pfhxs) Exposure To Risk Of Liver Disease Caused By High Fat Fructose Diet, Dwight C. Anderson May 2017

Evaluation Of Perfluorohexane Sulfonate (Pfhxs) Exposure To Risk Of Liver Disease Caused By High Fat Fructose Diet, Dwight C. Anderson

Senior Honors Projects

Perfluorohexane sulfonate (PFHxS) has been used in products as surfactants[AS1] . These products include fluoropolymers and as protective and water-resistant coatings to different materials such as carpets, paper, and textiles. Also, evidence of PFHxS exposure has been reported in firefighters who use certain film forming foams. Current investigations have shown widespread exposure to PFHxS in the environment, specifically in drinking water. There has also been evidence of PFHxS accumulation in humans, with a half-life lasting several years.

PFHxS is one of several perfluoronated alkyl substances (PFAS). Other PFASs are considered to be hepatotoxic in rodents and potentially in humans. Studies …


Kepone In The James River Estuary: Past, Current And Future Trends, Michael A. Unger, George G. Vadas Apr 2017

Kepone In The James River Estuary: Past, Current And Future Trends, Michael A. Unger, George G. Vadas

Reports

In late 1975, a manufacturing facility in Hopewell, VA had not only exposed workers to the chlorinated pesticide, Kepone, but had also severely contaminated the James River estuary. To assess the potential risk to the public, Virginia initiated a finfish-monitoring program in late 1975. Over the next 40 years over 13,000 samples were collected from the James River and Chesapeake Bay and analyzed for Kepone. Kepone production was eventually banned worldwide. The average Kepone concentrations found in most species began falling when the production of Kepone ended, but the averages remained over the action limit of 0.3 mgkg-1 until …


From Disposable Culture To Disposable People: Teaching About The Unintended Consequences Of Plastics, Sasha Adkins Jan 2017

From Disposable Culture To Disposable People: Teaching About The Unintended Consequences Of Plastics, Sasha Adkins

Antioch University Full-Text Dissertations & Theses

Plastics, the epitome of disposable culture, pose both a toxicological and a spiritual problem. This dissertation examines plastics at a molecular level using the discourse of endocrine disruption, and at a sociological level using the discourses of eco-theology and environmental justice. Adding to the literature on the adsorption of toxicants to plastic marine debris, I demonstrate that certain types of plastic -- those containing mercaptans, such as styrene butadiene block copolymer -- efficiently concentrate methyl mercury from seawater. Further, samples of polycarbonate contributed mercury to seawater. I propose the term plastic-mediated magnification to describe the phenomenon that plastics, along with …


Use Of A Modified Greenscreen Tool To Conduct A Screening-Level Comparative Hazard Assessment Of Conventional Silver And Two Forms Of Nanosilver., Jennifer Sass, Lauren Heine, Nina Hwang Nov 2016

Use Of A Modified Greenscreen Tool To Conduct A Screening-Level Comparative Hazard Assessment Of Conventional Silver And Two Forms Of Nanosilver., Jennifer Sass, Lauren Heine, Nina Hwang

Environmental and Occupational Health Faculty Publications

BACKGROUND: Increased concern for potential health and environmental impacts of chemicals, including nanomaterials, in consumer products is driving demand for greater transparency regarding potential risks. Chemical hazard assessment is a powerful tool to inform product design, development and procurement and has been integrated into alternative assessment frameworks. The extent to which assessment methods originally designed for conventionally-sized materials can be used for nanomaterials, which have size-dependent physical and chemical properties, have not been well established. We contracted with a certified GreenScreen profiler to conduct three GreenScreen hazard assessments, for conventional silver and two forms of nanosilver. The contractor summarized publicly …


Aneuploidy: A Common And Early Evidence-Based Biomarker For Carcinogens And Reproductive Toxicants., Daniele Mandrioli, Fiorella Belpoggi, Ellen K Silbergeld, Melissa J. Perry Oct 2016

Aneuploidy: A Common And Early Evidence-Based Biomarker For Carcinogens And Reproductive Toxicants., Daniele Mandrioli, Fiorella Belpoggi, Ellen K Silbergeld, Melissa J. Perry

Environmental and Occupational Health Faculty Publications

Aneuploidy, defined as structural and numerical aberrations of chromosomes, continues to draw attention as an informative effect biomarker for carcinogens and male reproductive toxicants. It has been well documented that aneuploidy is a hallmark of cancer. Aneuploidies in oocytes and spermatozoa contribute to infertility, pregnancy loss and a number of congenital abnormalities, and sperm aneuploidy is associated with testicular cancer. It is striking that several carcinogens induce aneuploidy in somatic cells, and also adversely affect the chromosome compliment of germ cells. In this paper we review 1) the contributions of aneuploidy to cancer, infertility, and developmental abnormalities; 2) techniques for …