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Human Toxicology Of Chemical Mixtures

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Human Toxicology of Chemical Mixtures

Human Toxicology of Chemical Mixtures Book
Author : Harold Zeliger
Publisher : William Andrew
Release : 2011-06-24
ISBN : 9781437734645
Language : En, Es, Fr & De

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Book Description :

In this important reference work, Zeliger catalogs the known effects of chemical mixtures on the human body and also proposes a framework for understanding and predicting their actions in terms of lipophile (fat soluble) / hydrophile (water soluble) interactions. The author’s focus is on illnesses that ensue following exposures to mixtures of chemicals that cannot be attributed to any one component of the mixture. In the first part the mechanisms of chemical absorption at a molecular and macromolecular level are explained, as well as the body’s methods of defending itself against xenobiotic intrusion. Part II examines the sources of the chemicals discusssed, looking at air and water pollution, food additives, pharmaceuticals, etc. Part III, which includes numerous case studies, examines specific effects of particular mixtures on particular body systems and organs and presents a theoretical framework for predicting what the effects of uncharacterized mixtures might be. Part IV covers regulatory requirements and the need to adjust recommended exposure levels for products containing mixtures. It also contains recommendations on how to limit exposure to mixtures in the products we use and on how to limit release of mixtures into the environment. Providing brief summaries of each mixture and its effects, Zeliger provides a comprehensive reference, a jumping off point for professionals (with extensive chapter bibliographies) and an introduction to the topic for those studying traditional toxicology. Addressing many inadequately understood illnesses and conditions such as asthma, infertility and cancer, it will also be of interest to health professionals, environmental scientists and lawyers. Presents a theoretical framework for predicting the effects of chemical mixtures for which no specific data exists (this predictive aspect is important due to the vast number of different potential chemical combinations - far too many to comprehensively catalog) A quick and convenient source of hard to come by data on the rapidly developing field of chemical mixtures, for groups including chemists and engineers, toxicologists, health professionals and environmental scientists New and updated material comprises over 30% of this timely new edition, which includes the latest research data alongside an expanded introduction to the science and art of predicting the toxicological properties of chemical mixtures

Mixture Toxicity

Mixture Toxicity Book
Author : Cornelis A. M. van Gestel,Martijs Jonker,Jan E. Kammenga,Ryszard Laskowski,Claus Svendsen
Publisher : CRC Press
Release : 2016-04-19
ISBN : 9781439830093
Language : En, Es, Fr & De

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Book Description :

In the last decade and a half, great progress has been made in the development of concepts and models for mixture toxicity, both in human and environmental toxicology. However, due to their different protection goals, developments have often progressed in parallel but with little integration. Arguably the first book to clearly link ecotoxicology and classic human toxicology, Mixture Toxicity: Linking Approaches from Ecological and Human Toxicology incorporates extensive reviews of exposure to toxicants, toxicokinetics and toxicodynamics, toxicity of mixtures, and risk assessment. The book examines developments in both fields, compares and contrasts their current state of the art, and identifies where one field can learn from the other. Each chapter provides an essential overview of the state of the art in both human and ecotoxicological mixture risk assessment, focusing on the work published in the last fifteen years. The coverage progresses from exposure to risk assessment, at each step identifying the special complications typically raised by mixtures. Based on in-depth discussions among specialists representing different disciplines and approaches, the chapters each address: Exposure — how to quantify the amounts of chemicals that may enter the living organism Kinetics, dynamics, and metabolism — how the chemicals enter an organism, travel within the organism, how they are metabolized and reach the target site, and explain development of toxicity with time Toxicity — what are the chemicals’ detrimental effects on the organism Test design and complex mixture characterization — how chemicals interact, how to measure effects of mixtures, and how to identify responsible chemicals Risk assessment — how to assess for risks in humans and the environment An unusual combination of different points of view on exposure to and risk assessment of chemical mixtures, this book summarizes current knowledge on combined effects of toxicant mixtures, information that is generally only available in a very fragmented form as individual journal papers. It identifies possible crosslinks and includes recommendations for mutual developments that can improve the state of knowledge on mixture toxicity and ultimately lead to better and more integrated risk assessment.

Human Toxicology of Chemical Mixtures

Human Toxicology of Chemical Mixtures Book
Author : Harold Zeliger
Publisher : William Andrew
Release : 2008-07-25
ISBN : 0815519842
Language : En, Es, Fr & De

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Book Description :

This book considers how exposure to toxic mixtures affects the different physiological systems and organs, including the respiratory, cardiovascular, immunological, musculoskeletal, nervous and reproductive systems, as well as the various organs, including the kidneys, liver and skin. The author evaluates various sources of exposure, including air, water, and soil pollution; in utero exposure; chemicals contained in foods, cosmetics, and domestic cleaning products; adhesives and paints; industrial chemicals; pesticides; electromagnetic radiation; and chemicals ingested or inhaled during the use of alcohol, tobacco and narcotics. The book also examines the interplay between exposure to these mixtures and the prevalence of various diseases and conditions, including autism, attention deficit hyperactivity disorder (ADHD), developmental neurotoxicology, multiple chemical sensitivity (MSC), chronic fatigue syndrome (CFS), fibromyalgia (FM), Gulf war syndrome, cancer and cancer clusters. The author also discusses how exposure to these mixtures yields the above diseases and conditions in different populations: fetuses, infants, pre-adolescent children, adolescents and adults. Finally, the book addresses the profound policy implications for formulation, labeling and use of chemical products, and it proposes more stringent exposure limits and warning requirements in light of the newly recognized toxic effects that are directly attributable to the mixture of toxic lipophilic and hydrophilic chemicals. * Addresses chemical mixtures, while most literature only deals with single chemicals exposure. * Explains why certain toxicological effects are observed. * Discusses diagnosis and treatment of injuries resulting from exposure. * Explores consequences of effects on product formulation, use, handling and required warnings. * Provides guidelines for safer development of personal care, cosmetic, industrial and consumer use products.

Toxicology of Chemical Mixtures

Toxicology of Chemical Mixtures Book
Author : Raymond S.H. Yang
Publisher : Elsevier
Release : 2016-05-14
ISBN : 1483289400
Language : En, Es, Fr & De

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Book Description :

Although toxicologic studies in the laboratory often focus on a single chemical, in the larger world, mixtures of chemicals are routinely encountered. Toxicology of Chemical Mixtures examines the mechanisms of interactions and health effects stemming from chemical mixtures in the environment. Toxicologists, pharmacologists, environmental scientists, and professionals involved in environmental clean-ups will benefit from its content. Emphasis is on low-level, long-term exposure. Key Features * Some of the issues addressed include: * Target organ toxicities in response to chemical mixture exposures * Risk assessment and experimental approaches * Case studies and special pollution problems * Special pollution problems

The Toxicology of Chemical Mixtures Risk Assessment for Human and Ecological Receptors

The Toxicology of Chemical Mixtures Risk Assessment for Human and Ecological Receptors Book
Author : Anonim
Publisher : Unknown
Release : 2005
ISBN : 0987650XXX
Language : En, Es, Fr & De

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Book Description :

Mixtures of chemicals represent a concern in all areas of toxicology and a challenge to risk assessors as most sites with environmental contamination, including Department of Defense sites, involve simultaneous or sequential exposures of multiple chemicals to human or ecological receptors. A major concern with mixtures is that they may lead to outcomes (health effects) or increased toxicity (synergism) not expected from the risk characterization of individual chemicals at the site. The focus of this literature review is 0 examine the principles used to determine toxicity in chemical mixtures risk assessment for human and ecological receptors at hazardous waste sites. This review provides an overview of current practices useful to a remedial project manager or risk assessor prior to their first chemical mixtures risk assessment.

The Toxicity of Chemical Mixtures

The Toxicity of Chemical Mixtures Book
Author : J. K. Pollak
Publisher : Unknown
Release : 1993
ISBN : 9780867587753
Language : En, Es, Fr & De

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Book Description :

Download The Toxicity of Chemical Mixtures book written by J. K. Pollak, available in PDF, EPUB, and Kindle, or read full book online anywhere and anytime. Compatible with any devices.

Genetic Toxicology of Complex Mixtures

Genetic Toxicology of Complex Mixtures Book
Author : Michael D. Waters,F.Bernhard Daniel,Joellen Lewtas,Martha M. Moore,Stephen Nesnow
Publisher : Springer Science & Business Media
Release : 2013-03-13
ISBN : 1468458507
Language : En, Es, Fr & De

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Book Description :

Contained in this volume are the proceedings of the international conference on the "Genetic Toxicology of Complex Mixtures," held from July 4-7, 1989, in Washington, DC. This meeting was a satellite of the "Fifth International Conference on Environmental Mutagens" and the seventh in a biennial series of conferences on "Short-term Bioassays in the Analysis of Complex Environmental Mixtures. " Our central objective in calling together key researchers from around the world was to extend our knowledge of the application of the methods of genetic toxicology and analytical chemistry in the evaluation of chemical mixtures as they exist in the environment. This conference emphasized the study of genotoxicants in air and water, and the assessment of human exposure and cancer risk. The latest strategies and methodologies for biomonitoring of genotoxicants (including transformation products) were described in the context of the ambient environment. Source character ization and source apportionment were discussed as an aid to understand ing the origin and relative contribution of various kinds of complex mix tures to the ambient environment. Similarly, investigations of genotoxi cants found in the indoor environment (sidestream cigarette smoke) and in drinking water (chlorohydroxyfuranones) were given special attention in terms of their potential health impacts. New molecular techniques were described to enable more precise quantitation of internal dose and dose to-target tissues. The emphasis of presentations on exposures/effects assessment was on integrated quantitative evaluation of human exposure and potential health effects.

Chemical Mixtures and Combined Chemical and Nonchemical Stressors

Chemical Mixtures and Combined Chemical and Nonchemical Stressors Book
Author : Cynthia V. Rider,Jane Ellen Simmons
Publisher : Springer
Release : 2018-02-16
ISBN : 3319562347
Language : En, Es, Fr & De

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Book Description :

In this book, both basic and advanced concepts are discussed for considering mixtures from initial exposure characterization through evaluation of risk associated with combined exposures. This book will provide an introduction to key issues and multiple options for evaluating both the toxicity of mixtures as well as the risk associated with exposure to mixtures. Additionally, promising tools adapted from other disciplines will be discussed in the context of mixtures toxicology and risk assessment. Finally, the discussion will move beyond chemical mixtures to address incorporating non-chemical stressors into toxicity studies and cumulative risk assessments. Although exposure to multiple chemical and non-chemical stressors is the rule, not the exception, consideration of mixtures in toxicology and risk assessment continues to be a significant challenge. This book will be an essential resource for researchers and professionals in the fields of toxicology, epidemiology, exposure science, risk assessment, and statistics.

Principles and Practice of Mixtures Toxicology

Principles and Practice of Mixtures Toxicology Book
Author : Moiz Mumtaz
Publisher : John Wiley & Sons
Release : 2011-05-23
ISBN : 3527632115
Language : En, Es, Fr & De

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Book Description :

This first comprehensive treatment of the subject for more than a decade includes the latest research on nanoparticle toxicology. The practical handbook addresses all areas where toxic mixtures are encountered, from environmental via occupational to medical settings, giving special consideration to air and water, and to the specific requirements for study design in mixture toxicology. While no extensive prior knowledge or toxicological experience is required, the practice-oriented case studies and examples in the second part make this the ideal companion for the professional toxicologist in industry or healthcare institutions with little time for academic study.

A Pound of Prevention for a Healthier Life

A Pound of Prevention for a Healthier Life Book
Author : Harold I. Zeliger
Publisher : Universal-Publishers
Release : 2019-04-15
ISBN : 1627342648
Language : En, Es, Fr & De

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Book Description :

A Pound of Prevention for a Healthier Life shows the connection between oxidative stress and the onset of virtually all disease and discusses the causes of oxidative stress induced disease and ways to prevent it. The book includes a unique questionnaire for predicting disease onset in seemingly healthy people, and shows how steps taken to prevent any one disease may prevent many other unrelated diseases. Dr. Harold I. Zeliger, a chemical toxicologist who has been researching the causes of non-communicable diseases for more than 40 years, demonstrates how elevated oxidative stress is responsible for attacks on virtually all body organs and systems and how it triggers the onset of numerous diseases, including ADHD, autism, heart disease, respiratory disease, diabetes, obesity, Alzheimer?s disease, Parkinson?s disease, cancer and numerous others. The many sources of oxidative stress include not only exposures to toxic chemicals such as pesticides, air pollutants, PCBs and organic solvents, but also to radiation, tobacco smoke, eating some foods, pharmaceutical drug use, illnesses a person already has, emotional stress and others. Zeliger?s research shows how elevated oxidative stress need not come from a single source, but can come from multiple sources, and that it is total oxidative stress, no matter what the source or sources, that causes disease. The Oxidative Stress Index, which can be individually arrived at from the questionnaire in the book, allows the reader to determine his or her oxidative stress level, which sources are responsible for it, and what actions can be taken to reduce it and lower the likelihood of disease onset.

Toxicology of Chemical Mixtures Experimental Approaches Underlying Concepts and Some Results

Toxicology of Chemical Mixtures  Experimental Approaches  Underlying Concepts  and Some Results Book
Author : Raymond S. Yang,H. L. Long,Gary A. Boorman,NATIONAL INST OF ENVIRONMENTAL HEALTH SCIENCES RESEARCH TRIANGLE PARK NC.
Publisher : Unknown
Release : 1990
ISBN : 0987650XXX
Language : En, Es, Fr & De

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Book Description :

The toxicology of chemical mixtures will be the toxicology of the 1990s and beyond. While this branch of toxicology most closely reflects the actual human exposure situation, as yet, there is no standard protocol or consensus methodology for investigating the toxicology of mixtures. Thus, in this emerging science, experimentation is required just to develop a broadly applicable evaluation system. Several examples are discussed to illustrate the different experimental designs and the concepts behind each. These include the health effects studies of Love Canal soil samples, the Lake Ontario Coho salmon, the water samples repurified from secondary sewage in the city of Denver Potable Water Reuse Demonstration Plant, and the National Toxicology Program (NTP) effort on a mixture of 25 frequently detected groundwater contaminants derived from hazardous waste disposal sites. In the last instance, an extensive research program has been ongoing for the last two years at the NTP, encompassing general toxicology, immunotoxicology, developmental and reproductive toxicology, biochemical toxicology, myelotoxicology, genetic toxicology, neurobehavioral toxicology, and hepato- and renal toxicology.

Diversification in Toxicology Man and Environment

Diversification in Toxicology     Man and Environment Book
Author : Jürg P. Seiler,Judith L. Autrup,Herman Autrup
Publisher : Springer Science & Business Media
Release : 2012-12-06
ISBN : 364246856X
Language : En, Es, Fr & De

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Book Description :

This volume contains the main papers presented at the 1997 EUROTOX Congress, Århus, Denmark, 24-28 June 1997. Diversification in toxicology is seen as the application of basic science to such diverse areas as man and his environment. The pressing issues which have been dealt with not only include reproductive effects of environmental chemicals ("xenoestrogens"), but also receptor-mediated toxic responses, new frontiers in human and ecological toxicology, chemoprevention of cancer and molecular approaches in toxicological research. The practical and ethical facets of toxicology, e.g. ecotoxicological risk assessment, biomarkers of exposure, complex chemical mixtures as well as animal welfare and the ethics of animal experimentation, are also treated.

Toxicological Risk Assessment of Chemicals

Toxicological Risk Assessment of Chemicals Book
Author : Elsa Nielsen,Grete Ostergaard,John Christian Larsen
Publisher : CRC Press
Release : 2008-02-21
ISBN : 9780849372650
Language : En, Es, Fr & De

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Book Description :

Unlike many existing books on toxicology that cover either toxicity of a particular substance or toxicity of chemicals on particular organ systems, Toxicological Risk Assessment of Chemicals: A Practical Guide lays out the principle activities of conducting a toxicological risk assessment, including international approaches and methods for the risk assessment of chemical substances. It illustrates each step in the process: hazard identification, a dose response assessment, and exposure assessment. The book also summarizes the basic concepts of interaction of chemicals in mixtures and discusses various approaches to testing such mixtures. Features: Addresses standards from all international regulatory agencies Presents the steps in risk assessment, including hazard identification, exposure assessment, and risk characterization Covers the assessment of multiple chemical exposures or chemical mixtures Contains data from both human and animal studies Explains the linearized multi-stage mathematical model widely used by the US EPA for characterizing

Fish Physiology Organic Chemical Toxicology of Fishes

Fish Physiology  Organic Chemical Toxicology of Fishes Book
Author : Keith B. Tierney,Anthony P. Farrell,Colin J. Brauner
Publisher : Academic Press
Release : 2013-12-04
ISBN : 0123982553
Language : En, Es, Fr & De

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Book Description :

Fish Physiology: Organic Chemical Toxicology of Fishes discusses the different types of organic chemical contaminants and their respective toxic effects in fish. The book also covers the detection of dissolved organic compounds and methods to assess organic toxicity. Substances addressed in this book include organometallics, hydrocarbons, endocrine disrupting compounds (EDCs), insecticides, herbicides, and pharmaceuticals. Fish are exposed to an ever-increasing array of organic chemicals that find their way into rivers and oceans. Some of these compounds are no longer being produced but nonetheless persist within the environment (persistent organic pollutants, or POPs). The exposure of fish to toxic organic compounds has potential impact on human, fish, and ecosystem health. Yet the regulations that govern environmental water quality vary worldwide, and compliance is never complete. This book provides a crucial resource on these issues for researchers in zoology, fish physiology, and related fields; applied researchers in environmental monitoring, conservation biology, and toxicology; and university-level students and instructors in these areas. Organized by type of toxic organic chemicals Includes metals, POPs, EDCs, herbicides, insecticides, and pharmaceuticals Measures toxicity in a variety of ways aside from lethality Probes the toxic effects of compound mixtures as well as single pollutants

Oxidative Stress

Oxidative Stress Book
Author : Harold Zeliger
Publisher : Academic Press
Release : 2022-09-01
ISBN : 0323914586
Language : En, Es, Fr & De

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Book Description :

Oxidative Stress: Its Impact on Human Health and Disease Onset examines all factors known to elevate oxidative stress (OS) and the mechanism of OS disease causation. Sections cover the causes and prevention of oxidative stress, the types of chemical exposures and environmental factors that precipitate disease, disease hallmarks and biomarkers, disease clusters, disease co-morbidities, free radical attacks at the cellular level, and the Oxidative Stress Index tool, its premise, and how it can be used to identify the primary causes of specific diseases and predict the likelihood of disease onset. With comprehensive coverage of not only the impact of OS due to chemical exposure but also the consequences of environmental factors, this book is a valuable resource for researchers and scientists in toxicology and environmental science, health practitioners, public health professionals, and others who wish to broaden their knowledge on this topic. Covers the chemical exposures and environmental factors that cause oxidative stress Provides further understanding on the mechanisms of oxidative damage response and disease Shows how oxidative stress and its role can be determined non-invasively via the Oxidative Stress Index

Current Issues on Chemical Mixtures and Model Validation Concepts and Their Application to Lead Models

Current Issues on Chemical Mixtures and Model Validation Concepts and Their Application to Lead Models Book
Author : Raymond S. H. Yang,William A. Suk
Publisher : Unknown
Release : 2002-10-01
ISBN : 9780788185397
Language : En, Es, Fr & De

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Book Description :

Papers include: human health and chemical mixtures: an overview; public health challenges posed by chemical mixtures; toxicology of chemical mixtures: international perspective; maximum workplace concentration values and carcinogenicity classification for mixtures; 14 papers on biomedical and methodological advances on chemical mixtures; 6 papers on ecological engineering advances on chemical mixtures; and 16 papers on model validation concepts and their application to lead models.

Conference on Current Issues of Chemical Mixtures

Conference on Current Issues of Chemical Mixtures Book
Author : Raymond Yang,Colorado state univ fort collins
Publisher : Unknown
Release : 1998
ISBN : 0987650XXX
Language : En, Es, Fr & De

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Book Description :

Between 11 and 13 August 1997, a conference on Current Issues of Chemical Mixtures was held and hosted at Fort Collins, Colorado, by the Colorado State University (CSU) and the National Institute of Environmental Health Sciences (NIEHS) Superfund Basic Research Program (SBRP). Other sponsors of the conference included the Agency for Toxic Substances and Disease Registry (ATSDR), the U.S. Environmental Protection Agency (both the Office of Solid Waste and Emergency Response and the Region VIII Office), the U.S. Army Center for Environmental Health Research, and the Electric Power Research Institute (EPRI). Over 160 participants, coming from Canada, France, Germany, Japan, Mexico, the Netherlands, Norway, Sweden, and the U.S., are scientists, engineers, policy makers, and individuals with a profound interest in the issues related to hazardous waste disposal and contamination. The Conference consisted of six sessions: (1) Overview of Human Health and Regulatory Problems Related to Chemical Mixture Exposures; (2) Biomedical Advances on Chemical Mixtures I; (3) Biomedical Advances on Chemical Mixtures II; (4) Methodological Advances on the Toxicology of Chemical Mixtures; (5) Ecological and Engineering Advances on Chemical Mixture Research; and (6) Risk Assessment Issues Related to Hazardous Waste Chemical Mixtures.

Human Exposure to PAHs in Air Water and Crayfish

Human Exposure to PAHs in Air  Water  and Crayfish Book
Author : L. Blair Paulik
Publisher : Unknown
Release : 2016
ISBN : 0987650XXX
Language : En, Es, Fr & De

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Book Description :

There are many links between exposure to environmental pollution and risks to human health. While advances in the fields of toxicology, exposure science, and environmental chemistry have shown light on many of these links, many more research challenges remain. One major challenge is how to accurately characterize the toxicity of a mixture of chemical pollutants. There is evidence to suggest that assuming the toxicities of chemicals in a mixture are additive is an oversimplification. Additionally, there are many chemicals that are commonly found in the environment or that are potentially toxic, but that remain under-studied. All of these caveats apply to polycyclic aromatic hydrocarbons (PAHs). Another challenge is how to best quantify an individual’s exposure to environmental pollutants. Traditionally this is done using a combination of self-reported exposure information from questionnaires, extrapolation of data from stationary monitors to the exposures of mobile individuals, and occasionally data from personal monitors. Passive sampling is an effective tool for measuring the fraction of chemical pollutants people are exposed to in the environment. The work presented in this dissertation uses passive sampling to measure PAH contamination in air, water, and the personal environment, and to predict PAH concentrations in crayfish. It also estimates carcinogenic human health risks associated with exposure to this PAH contamination. Shellfish contamination data is needed for use in consumption advisories. However, existing methods of measuring this contamination are often prohibitively time and resource-intensive. It has been observed that passive samplers, coupled with predictive models, can accurately estimate PAH contamination in shellfish. In Chapter 2 we further validated the ability of passive water samplers and predictive models to predict PAH contamination in the resident signal crayfish, Pacifastacus leniusculus. This work was conducted within and outside of the Portland Harbor Superfund Megasite. We estimated PAH concentrations in crayfish from PAH concentrations measured by passive samplers in water, using a simple linear regression model that included 34 PAHs. The model predicted PAH concentrations in crayfish within an average factor of 2.4 of PAH concentrations that were measured in crayfish. Additionally, we observed substantially higher PAH levels, and carcinogenic PAH levels, in crayfish visceral tissue than in crayfish tails. This indicated that eating only the tail of a crayfish would drastically reduce a consumer’s cancer risk compared to eating the whole crayfish. We also demonstrated the importance of appropriately characterizing the toxicity of chemical mixtures. For instance, benzo[c]fluorene was identified as the main contributor to carcinogenic potency in crayfish tissues. However, this PAH is not traditionally included in analyses of environmental samples. Additionally, we saw strikingly similar profiles of carcinogenic PAHs in crayfish tissues collected in this Superfund site in 2003 and 2013. This demonstrated that there are chemical mixtures that commonly occur at this Superfund site. Knowing this could enable researchers to drastically reduce the number of chemical mixtures to prioritize for toxicological study. Natural gas extraction (NGE) activity has expanded rapidly in the U.S. in recent years. This rapid expansion has been met with minimal study of potential environmental or health effects, leading to concern among scientists and the public. In Chapters 3 and 4 we present two studies assessing the impact of NGE on environmental PAH levels, in a community heavily affected by the recent natural gas boom. In Chapter 3 we used passive air samplers to assess how proximity to the nearest active NGE well affected PAH concentrations in ambient air. In this study we saw decreasing PAH concentrations, as well as carcinogenic PAH concentrations, as air samplers moved farther from active NGE wells. We also saw predominantly petrogenic signatures of PAH mixtures measured closer to NGE wells. This suggested that measured PAH mixtures were impacted by fugitive emissions of PAHs during NGE, and that this impact was stronger closer to active NGE wells. In Chapter 4, we more thoroughly assessed spatial patterns of PAH concentrations in air using passive air samplers, at sites with and without active NGE wells. In this study we observed higher PAH concentrations in air at sites with NGE wells than at sites without. Again, we saw more petrogenic PAH mixtures at sites with active NGE wells than at sites without wells. This gave us further evidence that PAH mixtures in air near NGE wells are affected by direct releases from the earth during NGE. In this study we also assessed the impact of NGE on the personal PAH exposure of people living and working in this community. We did this using a novel personal passive sampler, the silicone wristband. PAH concentrations measured in wristbands demonstrated that living or working closer to an active NGE well was associated with increased PAH exposure. However, all carcinogenic PAH concentrations measured in air in both NGE studies were below the U.S. EPA’s acceptable threshold. Thus, even the highest carcinogenic PAH concentrations measured in air closest to NGE wells would not be expected to increase lifetime cancer risk of people living or working nearby above background risk levels. The work presented in this dissertation further validates the ability of passive samplers to predict PAH contamination in crayfish, provides evidence for PAH emissions coming from NGE, and comments on the estimated health risks associated with exposure to these PAH mixtures. Taken together these findings help solve the current challenges in environmental toxicology research, and provide ideas for solving the remaining challenges facing this field.

Computational Toxicology

Computational Toxicology Book
Author : Bruce A. Fowler
Publisher : Elsevier Inc. Chapters
Release : 2013-06-04
ISBN : 0128060425
Language : En, Es, Fr & De

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Book Description :

This book is intended to be an introduction to various applications of computational toxicology and to show how these approaches are currently being used effectively for risk assessment purposes in the near term. It is important to note that the field of computational toxicology is rapidly evolving and that subsequent editions of this book will take up new methods that are currently under development, such as high-throughput screening, and others that are still in a conceptual stage. There are many advantages for including computational toxicology approaches in the risk assessment process. Among these are reducing costs, minimizing use of animals in toxicology testing, improving speed in providing answers regarding chemicals in emergency situations such as the Gulf Oil spill, and dealing with the common problem of decision making for chemical mixtures. In addition, computational methods may be used for extrapolating or translating data from both in vitro and in vivo experimental animal test systems for human risk assessments of chemicals and drugs. In addition, computational methods may be used for focusing laboratory studies into productive areas by data mining the published literature and developing testable hypotheses by application of systems biology approaches to identify chemical interactions with functional molecular pathways to generate a more comprehensive picture of likely primary and secondary modes of chemical or drug activity. In summary, there is much that computational toxicology is now contributing to helping make better societal risk assessment decisions about chemicals and drugs. The future for these approaches is optimistic and limited only by human ingenuity and availability of resources.