Download or read book The Role of Polycyclic Aromatic Hydrocarbons in Developmental Toxicity of Petroleum Substances written by and published by . This book was released on 2019 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: cum laude graduation

Download or read book Toxicological Profile for Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Developmental Toxicity of Polycyclic Aromatic Hydrocarbons written by Britton C. Goodale and published by . This book was released on 2013 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment as components of fossil fuels and by-products of combustion. Defining toxicity mechanisms for this large family of multi-ring structures and substituted derivatives is a substantial challenge. Several PAHs, such as benzo(a)pyrene (BaP), are mutagenic, toxic to wildlife, and classified as probable carcinogens to humans. PAHs are present in the environment both in the gaseous phase as well as associated with particulates, and exposures occur via complex mixtures; combustion emissions contain PAHs along with many other contaminants. Cardiac dysfunction and adverse birth outcomes associated with exposure to airborne PAHs suggest that this family of compounds may have non-mutagenic biological activities that affect human health. Some PAHs exert toxic effects via binding the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor that mediates transcription of many downstream target genes, including cytochrome P450 metabolizing enzymes. Unlike planar halogenated hydrocarbons, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), PAHs are readily metabolized by CYP1A, CYP1B1 and other enzymes, which create reactive intermediates and/or facilitate excretion. Mechanisms of PAH toxicity therefore include canonical AHR signaling, induction of oxidative stress, and other lesser-understood activities that do not require the AHR. We employed zebrafish as a model to rapidly assess developmental toxicity, global transcriptional responses and AHR activation in embryos exposed to parent and oxygenated PAHs (OPAHs). Using comparative analysis of mRNA expression profiles from microarrays with embryos exposed to benz(a)anthracene (BAA), dibenzothiophene (DBT) and pyrene (PYR), we identified expression biomarkers and disrupted biological processes that precede developmental abnormalities. These transcriptional responses were associated with PAH body burdens in the embryos detected by GC-MS. We found that uptake data were essential for discerning molecular pathways from dose-related differences, and identified two primary toxicity profiles. While BAA disrupted transcripts involved in vasculogenesis, DBT and PYR misregulated ion homeostasis and muscle-related genes. NfKB signaling was predicted to be involved in both responses, but canonical AHR signaling was only activated by BAA. In order to study the role of the AHR in mediating toxicity of PAHs, we developed an AHR2 mutant zebrafish line, which has a mutation in the transactivation domain of AHR2. We used AHR agonists TCDD and leflunomide as toxicological probes to characterize AHR activity in the mutant line, and determined that the mutants were functionally null. Finally, we used AHR2 deficient zebrafish embryos to investigate mechanisms by which two four-ring OPAHs induced developmental effects. 1,9 benz-10-anthrone (BEZO) and benz(a)anthracene-7,12-dione (7,12-B[a]AQ) both caused malformations in developing embryos, but they differentially induced CYP1A expression. Despite this difference, the toxicity produced from both compounds was AHR2-dependent. We used mRNA-seq to compare the transcriptional profiles of BEZO and 7,12-B[a]AQ, and identified transcriptional networks that will be investigated further to determine how ligands differentially modulate AHR activity. We also discovered novel transcripts that are potentially important mediators of AHR toxic effects. Comparison across all five parent and OPAHs highlighted clusters of genes that, surprisingly, were similarly expressed in response to the OPAHs, DBT and PYR. These commonly-regulated transcripts may be important to consider when investigating toxicity of PAH mixtures. Together, these studies show that PAHs act via different transcriptional mechanisms, but can be categorized based on transcriptional profiles and differential AHR activation. The clusters of transcripts identified may be involved in common pathways; further investigation of transcription factors and coactivators that interact with mixexpressed genes is a promising area of research for elucidating diverse functions of the AHR.

Download or read book PAHs written by Peter E. T. Douben and published by John Wiley & Sons. This book was released on 2003-07-25 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs), or polyarenes, are one of the largest and most structurally diverse class of organic molecules known. High percentages of polyarenes, representing a wide range of molecular sizes and structural types, are present in coal tars and petroleum residues. The major sources of PAHs are crude oil, coal and oil shale. The fuels produced from these fossil sources constitute the primary source of energy for the industrial nations of the world, and the petrochemicals from these raw materials are the basis of the synthetic fibre and plastics industries. PAHs are however, widespread pollutants and their impact on the environment and human health must be monitored and controlled. This book will review and assess our scientific understanding of the ecological exposure and effects PAHs have in different environments and habitats. It will accomplish this by taking the recipients of the pollution in the environment as starting points and working its way back through pathways to access what is required for our understanding of effects and rationale for control. Although this book will concentrate on ecological exposure of PAHs, the general impacts of PAHs on human populations will be touched upon. It is thought to be the first book to focus on the ecological aspects of PAHs.

Download or read book WHO Guidelines for Indoor Air Quality written by and published by World Health Organization. This book was released on 2010 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents WHO guidelines for the protection of public health from risks due to a number of chemicals commonly present in indoor air. The substances considered in this review, i.e. benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especially benzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene, have indoor sources, are known in respect of their hazardousness to health and are often found indoors in concentrations of health concern. The guidelines are targeted at public health professionals involved in preventing health risks of environmental exposures, as well as specialists and authorities involved in the design and use of buildings, indoor materials and products. They provide a scientific basis for legally enforceable standards.

Download or read book Polycyclic Aromatic Hydrocarbons written by and published by National Academies. This book was released on 1983-01-01 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oil in the Sea III written by National Research Council and published by National Academies Press. This book was released on 2003-03-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the early 1970s, experts have recognized that petroleum pollutants were being discharged in marine waters worldwide, from oil spills, vessel operations, and land-based sources. Public attention to oil spills has forced improvements. Still, a considerable amount of oil is discharged yearly into sensitive coastal environments. Oil in the Sea provides the best available estimate of oil pollutant discharge into marine waters, including an evaluation of the methods for assessing petroleum load and a discussion about the concerns these loads represent. Featuring close-up looks at the Exxon Valdez spill and other notable events, the book identifies important research questions and makes recommendations for better analysis ofâ€"and more effective measures againstâ€"pollutant discharge. The book discusses: Inputâ€"where the discharges come from, including the role of two-stroke engines used on recreational craft. Behavior or fateâ€"how oil is affected by processes such as evaporation as it moves through the marine environment. Effectsâ€"what we know about the effects of petroleum hydrocarbons on marine organisms and ecosystems. Providing a needed update on a problem of international importance, this book will be of interest to energy policy makers, industry officials and managers, engineers and researchers, and advocates for the marine environment.

Download or read book Polynuclear Aromatic Compounds written by Lawrence B. Ebert and published by . This book was released on 1988 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents accounts of current research in polynuclear aromatic compounds, showing examples of studies both of pure compounds and of complex, fossil fuel related mixtures. Offers a thorough knowledge of aromatic chemistry through coverage of reduction, oxidation, and thermal reactions--including applications developed for both coal and petroleum materials. Featured topics include quantum chemical structure-reactivity relationships, spatial configurations of large polynuclear hydrocarbons, cyclophanes, and desulfurization of heterocycles. Scientists studying all aspects of the chemistry of polynuclear aromatics will discover important, pertinent information in this volume.

Download or read book Development of a Background Document on the Carcinogenicity Mutagenicity and Reproductive Toxicity Including the Related Respective Mode of Action of Polycyclic Aromatic Hydrocarbons PAHs written by and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Additivity of substances in a mixture with known toxicity and classified for the same endpoint is applied for certain endpoints in the classification criteria of the UN GHS and the EU CLP Regulation. This is applied in cases where data on the mixture itself is not available, and classification is based on the classification of substances. This approach has been explicitly described for acute toxicity, corrosion/irritation to skin, serious eye damage/eye irritation and, under certain conditions, for Specific Target Organ Toxicity (STOT). This is based on the assumption that all substances exerting this hazardous effect contribute to the overall hazard of the mixture in proportion to their concentration and potency. A mixture is classified as hazardous when the sum of the concentrations of such substances present in the mixture above the specified cut-off value (applying a weighting factor for potency where appropriate) exceeds the applicable concentration limit specified in the regulatory text. For these hazard classes, additivity applies irrespective of the mode of action of the various substances as long as the hazard endpoint is the same for the ingredient substances. Following Article 11(1) of CLP, such an approach is equally applicable for substances containing constituents displaying the above hazard property. It is currently being explored whether the principle of additivity is applicable in certain cases when classifying mixtures (or complex substances) for other hazard endpoints, especially for CMR endpoints where classification is to be based on available information for the substances rather than for the whole mixture. In this context, the objective of this project was to conduct a detailed scientific assessment to provide the information base for the assessment and selection of different options for how the principle of additivity Additivity of substances in a mixture with known toxicity and classified for the same endpoint is applied for certain endpoints in the classification criteria of the UN GHS2 and the EU CLP Regulation. This is applied in cases where data on the mixture itself is not available, and classification is based on the classification of substances. This approach has been explicitly described for acute toxicity, corrosion/irritation to skin, serious eye damage/eye irritation and, under certain conditions, for Specific Target Organ Toxicity (STOT). This is based on the assumption that all substances exerting this hazardous effect contribute to the overall hazard of the mixture in proportion to their concentration and potency. A mixture is classified as hazardous when the sum of the concentrations of such substances present in the mixture above the specified cut-off value (applying a weighting factor for potency where appropriate) exceeds the applicable concentration limit specified in the regulatory text. For these hazard classes, additivity applies irrespective of the mode of action of the various substances as long as the hazard endpoint is the same for the ingredient substances. Following Article 11(1) of CLP, such an approach is equally applicable for substances containing constituents displaying the above hazard property. It is currently being explored whether the principle of additivity is applicable in certain cases when classifying mixtures (or complex substances) for other hazard endpoints, especially for CMR endpoints where classification is to be based on available information for the substances rather than for the whole mixture. In this context, the objective of this project was to conduct a detailed scientific assessment to provide the information base for the assessment and selection of different options for how the principle of additivity could be applied to carcinogenic, mutagenic and reprotoxic (CMR) PAH constituents of petroleum and coal (PetCo) substances. In order to support the European Commission and the ECHA Risk Assessment Committee (RAC) in the preparation of options for potential PAH additivity, the current study focused on the following activities: - Task 1 - Compile available additional scientific information on the CMR toxicity of PAH constituents of petroleum and coal-derived UVCB (unknown or variable composition, complex reaction products or of biological materials) and multi-constituent substances registered under the Registration, Evaluation, Authorisation, and restriction of Chemicals (REACH) regulation and their modes of action (MoA). - Task 2 - Identify groups of PAHs for which additivity could potentially be applied. PAHs included in the scope of this project have the following characteristics: - PAHs which only contain carbon and hydrogen (homocyclic). Heterocyclic PAHs have not been included. - Unsubstituted and alkylated PAHs with 2-7 rings and, in the case of alkylated PAHs, a maximum chain length of 4 carbons. PAHs substituted with non-alkyl groups have not been included.

Download or read book Handbook of Polycyclic Aromatic Hydrocarbons written by Bjorseth and published by CRC Press. This book was released on 1985-12-06 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume concerns sources of polycyclic aromatic hydrocarbons (PAH), their emission factors, and relative importance. It deals with exposure, uptake, metabolism, and detection of PAH in the human body. The volume contains an update of information in environmental and biochemical studies of PAH.

Download or read book Deposition of Air Pollutants to the Great Waters written by and published by . This book was released on 1997 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coal Tar Creosote written by C. Melber and published by WHO. This book was released on 2004 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: On cover: IPCS International Programme on Chemical Safety. Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization and the World Health Organization, and produced within the framework of the Inter-organization Programme for the Sound Management of Chemicals (IOMC)

Download or read book Provisional Guidance for Quantitative Risk Assessment of Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrocarbon Pollution and its Effect on the Environment written by Muharrem Ince and published by BoD – Books on Demand. This book was released on 2019-12-04 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers hydrocarbon pollution, measurement techniques for hydrocarbons, risk assessment, and environmental impact. This comprehensive book takes a broad view of the subject and integrates a wide variety of approaches. This book attempts to address the needs of graduate and postgraduate students and other professionals or readers interested in food, soil, water, and air pollution. The aim of this book is to explain and clarify important studies, and compare and develop the new and groundbreaking measurement techniques. Written by leading experts in their respective areas, the book is highly recommended to professionals interested in environmental and human health because it provides specific and comprehensive examples.

Download or read book Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

Download or read book Pyrolysis of Organic Molecules written by Serban C. Moldoveanu and published by Elsevier. This book was released on 2009-09-16 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyrolysis of Organic Molecules with Applications to Health and Environmental Issues, the 28th volume in the Techniques and Instrumentation in Analytical Chemistry series, gives a systematic and comprehensive description of pyrolysis of non-polymeric organic molecules. Pyrolysis is involved in many practical applications as well as in many common human activities, but harmful compounds can be generated in the process. The study of pyrolysis and of the formation of undesirable compounds as a result of pyrolytic processes is of considerable interest to chemists, chemical engineers, and toxicologists. Pyrolysis results for compounds not previously studied or reported Updated information from a large body of results published on pyrolysis of individual compounds or classes of compounds Information on mechanisms and kinetics of numerous pyrolytic processes

Download or read book The Utilization of Bioremediation to Reduce Soil Contamination Problems and Solutions written by Václav Sasek and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional reliance on chemical analysis to understand the direction and extent of treatment in a bioremediation process has been found to be inadequate. Whereas the goal of bioremediation is toxicity reduction, few direct, reliable measures of this process are as yet available. Another area of intense discussion is the assessment of market forces contributing to the acceptability of bioremediation. Finally, another important component is a series of lectures and lively exchanges devoted to practical applications of different bioremediation technologies. The range of subjects covers a wide spectrum, encompassing emerging technologies as well as actual, full-scale operations. Examples discussed include landfarming, biopiling, composting, phytoremediation and mycoremediation. Each technology is explored for its utility and capability to provide desired treatment goals. Advantages and limitations of each technology are discussed. The concept of natural attenuation is also critically evaluated since in some cases where time to remediation is not a significant factor, it may be an alternative to active bioremediation operations.