Download or read book Occurrence and Toxicity of Photomodified Polycyclic Aromatic Hydrocarbon Mixtures Present in Contaminated Sediments written by BJ. McConkey and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exposure of PAHs to solar radiation results in the generation of oxygenated products. Many of these oxyPAHs are more toxic and/or carcinogenic than the parent compounds. Environmental photomodification of PAHs could result in formation of toxic compounds not anticipated by regulatory agencies. We have confirmed the presence of oxyPAHs at toxic levels in sediment samples taken from a known contaminated site. Contaminated sediment samples were taken from Hamilton Harbour (Hamilton, Ontario). A reference site from the harbour, known to be free of contaminants was also analyzed. High performance liquid chromatography (HPLC) was used to fractionate, and analyze individual compounds present. Fractions were tested for toxicity using both short-term, and long-term assays on the bacterium Vibrio fischeri.OxyPAHs were found in sediments at concentrations comparable to intact PAHs. Testing confirmed toxicity in fractions containing oxyPAHs on the order of intact PAH-containing fractions. It is concluded that environmental photomodification of PAHs contributes to the presence of toxic compounds that are not properly addressed by current regulations in the U.S. and Canada.
Download or read book Environmental Toxicology and Risk Assessment written by Bruce M. Greenberg and published by ASTM International. This book was released on 2001 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Environmental Soil Science written by Jianming Xu and published by Springer Science & Business Media. This book was released on 2014-01-07 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the “International Symposium of Molecular Environmental Soil Science at the Interfaces in the Earth’s Critical Zone,” this book focuses on the Critical Zone supporting life at the Earth’s surface with emphasis on the new and emerging subject area of molecular environmental soil science. Advances in research methodology, the use of synchrotron radiation in particular, are extensively reviewed. Roles of microbes, biomolecules, and environmental nanoparticles in mineral transformations, metal cycling, degradation of natural and anthropogenic organic compounds are also extensively reviewed. It is unique in terms of facilitating the integration of contributions from traditionally separate disciplines and adding a molecular and nanoparticle (therefore chemical) dimension to a field of endeavour that has traditionally been viewed on a different scale (dimension). It will also contribute to identifying knowledge gaps, providing future research directions and promoting research and education at the molecular level in this extremely important and challenging area of science for years to come. The IUPAC Project Committee noted that the Conference identifies, and builds on, the need to view and understand the Critical Zone at the molecular level. The book will be an invaluable reference for research and education.
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 Environmental Toxicology and Chemistry written by and published by . This book was released on 2007 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions in the Toxicity of Polycyclic Aromatic Hydrocarbon and Metal Mixtures written by Andrew Maier and published by . This book was released on 2000 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixtures of Metals and Polycyclic Aromatic Hydrocarbons Lead to Complex Toxic Outcomes in the Freshwater Amphipod Hyalella Azteca written by Patrick Gauthier and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of ecotoxicology inevitably must address the fact that toxicants always occur in mixture. Unfortunately, our present state of knowledge in terms of predicting the effects of contaminant mixtures and understanding the mechanisms by which a mixture can produce non-additive (e.g., antagonistic or synergistic) toxicity is insufficient to advise regulatory authorities on appropriate water quality objectives for the protection of aquatic life. Metals and polycyclic aromatic hydrocarbons (PAHs) are two ubiquitous contaminants that are often associated with similar effluent sources, such as bitumen and municipal waste. The adverse toxicological effects that metals and PAHs produce have given these contaminants the status of "priority pollutants" in many countries, including the USA and Canada. Thus, understanding their toxicological effects when in mixture should also be a priority. However, to date, there have been only 11 studies that have investigated the potential for metals and PAHs to produce non-additive toxicity. Of these 11 studies, reports of more-than-additive lethality have been equally common as strictly-additive lethality, raising concern over the largely ignored ecological risk these contaminants types produce when in mixture. The research outlined in this dissertation expands our understanding by providing the first comprehensive review of mechanistic aspects of metal-PAH mixture toxicity that likely amount to more-than-additive co-toxicity. This dissertation outlines experimental work investigating the additivity of binary mixtures of Cu, Cd, Ni, and V, with either phenanthrene (PHE) or phenanthrenequinone (PHQ), two common PAHs. For cases where more-than-additive mortality was found, additional experimentation was carried out to explore interactive toxic mechanisms in attempt to explain why certain mixtures of metals and PAHs produce more-than-additive lethality. Finally, the effects of Cu, PHE, and Cu-PHE mixtures were studied in terms of their effects on behaviour, a sublethal endpoint that mediates ecological effects which can also be used to predict toxic mechanisms. All experimental work outlined in this dissertation involved the aquatic crustacean amphipod, Hyalella azteca, which was selected due to its tractability in a laboratory setting, its ecological importance as a food source for fish, amphibians, and waterfowl, and its widespread distribution throughout North and Central America.
Download or read book Environmental Photooxidation and Mixture Toxicity of Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal and Polycyclic Aromatic Hydrocarbon Contaminants in Benthic Sediments of Port Curtis written by and published by . This book was released on 2006 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Aquatic Toxicity Workshop written by and published by . This book was released on 2003 with total page 372 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 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 Ecological Impacts of Toxic Chemicals written by Francisco Sánchez-Bayo, Paul J. van den Brink, Reinier M. Mann and published by Francisco Sanchez-Bayo. This book was released on 2011-09-09 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecological Impacts of Toxic Chemicals presents a comprehensive, yet readable account of the known disturbances caused by all kinds of toxic chemicals on both aquatic and terrestrial ecosystems. Topics cover the sources of toxicants, their fate and distribution through the planet, their impacts on specific ecosystems, and their remediation by natural systems. Each chapter is written by well-known specialists in those areas, for the general public, students, and even scientists from outside this field. The book intends to raise awareness of the dangers of chemical pollution in a world dominated by industry and globalization of resources. Because the problems are widespread and far reaching, it is hoped that confronting the facts may prompt better management practices at industrial, agricultural and all levels of management, from local to governmental, so as to reduce the negative impacts of chemical contaminants on our planet.
Download or read book Oil Spill Dispersants written by Committee on Understanding Oil Spill Dispersants: Efficacy and Effects and published by . This book was released on 2005 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approximately 3 million gallons of oil or refined petroleum products are spilled into U.S. waters every year. Oil dispersants (chemical agents such as surfactants, solvents, and other compounds) are used to reduce the effect of oil spills by changing the chemical and physical properties of the oil. By enhancing the amount of oil that physically mixes into the water, dispersants can reduce the potential that a surface slick will contaminate shoreline habitats. Although called for in the Oil Pollution Act of 1990 as a tool for minimizing the impact of oil spills, the use of chemical dispersants has long been controversial. This book reviews the adequacy of existing information and ongoing research regarding the effectiveness of dispersants as an oil spill response technique, as well as the effect of dispersed oil on marine and coastal ecosystems. Oil Spill Dispersants also includes recommended steps for policy makers faced with making hard choices regarding the use of dispersants as part of spill contingency planning efforts or during actual spills.
Download or read book UV Effects in Aquatic Organisms and Ecosystems written by E Walter Helbling and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers extensive coverage of the most important aspects of UVR effects on all aquatic (not just freshwater and marine) ecosystems, encompassing UV physics, chemistry, biology and ecology. Comprehensive and up-to-date, UV Effects in Aquatic Organisms and Ecosystems aims to bridge the gap between environmental studies of UVR effects and the broader, traditional fields of ecology, oceanography and limnology. Adopting a synthetic approach, the different sections cover: the physical factors controlling UVR intensity in the atmosphere; the penetration and distribution of solar radiation in natural waters; the main photochemical process affecting natural and anthropogenic substances; and direct and indirect effects on organisms (from viruses, bacteria and algae to invertebrate and vertebrate consumers). Researchers and professionals in environmental chemistry, photochemistry, photobiology and cell and molecular biology will value this book, as will those looking at ozone depletion and global change.
Download or read book Photobiology written by Lars Olof Björn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photobiology - the science of light and life - begins with basic principles and the physics of light and continues with general photobiological research methods, such as generation of light, measurement of light, and action spectroscopy. In an interdisciplinary way, it then treats how organisms tune their pigments and structures to the wavelength components of light, and how light is registered by organisms. Then follow various examples of photobiological phenomena: the design of the compound eye in relation to the properties of light, phototoxicity, photobiology of the human skin and of vitamin D, photomorphogenesis, photoperiodism, the setting of the biological clock by light, and bioluminescence. A final chapter is devoted to teaching experiments and demonstrations in photobiology. This book encompasses topics from a diverse array of traditional disciplines: physics, biochemistry, medicine, zoology, botany, microbiology, etc., and makes different aspects of photobiology accessible to experts in all these areas as well as to the novice.
Download or read book Modern Tools and Techniques to Understand Microbes written by Ajit Varma and published by Springer. This book was released on 2017-04-21 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides essential molecular techniques and protocols for analyzing microbes that are useful for developing novel bio-chemicals, such as medicines, biofuels, and plant protection substances. The topics and techniques covered include: microbial diversity and composition; microorganisms in the food industry; mass cultivation of sebacinales; host-microbe interaction; targeted gene disruption; function-based metagenomics to reveal the rhizosphere microbiome; mycotoxin biosynthetic pathways; legume-rhizobium symbioses; multidrug transporters of yeast; drug-resistant bacteria; the fungal endophyte piriformospora indica; medicinal plants; arbuscular mycorrhizal fungi; biosurfactants in microbial enhanced oil recovery; and biocontrol of the soybean cyst nematode with root endophytic fungi; as well as microbe-mediated drought tolerance in plants.
