63 research outputs found

    Organic Chemicals in Sediments from the Lower Chesapeake Bay

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    Many of the toxic organic chemicals affecting the marine environment are hydrophobic and associate with sediments. Sediments can accumulate the substances over long intervals and store them after the original source of the toxic material has been eliminated. Contaminated sediments can provide small but damaging amounts of the to.xicant to the overlying water for decades. For example, more than 10 years after the discovery of Kepone in the James River, Virginia, much of the James\u27 fisheries ·is still closed because Kepone levels are above federal action levels.https://scholarworks.wm.edu/vimsbooks/1166/thumbnail.jp

    Trace organic analyses of effluent waters from a model slurry pipeline carrying Appalachian bituminous coal : final report

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    Effluent waters from a model coal slurry pipeline have been analyzed for trace dissolved organic compounds. The model pipeline was operated under conditions simulating those proposed for a slurry pipeline from the region of Bristol to Hampton Roads, Virginia. Acidic, neutral and basic organic compounds in the separated waters were determined. Concentrations of individual compounds detected were generally less than 0.5 ppb and never exceeded 6 ppb. Adsorption experiments using coal slurry sorbents indicate that coal particles act as sorbing surfaces under coal slurry pipeline transport conditions

    Richmond Crater James River Water Quality Management Program, final report 1984-85 and summary, toxic organics in sediments : a final report to Richmond Regional Planning District

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    The following report contains detailed results of analyses of sediment grabs and cores from the James and Appomattox rivers and some nearby locations for a spectrum of organic toxics. Some data has been previously reported in interim progress reports, but will be included for completeness. A study of variability of replicate samples taken at a single station (JR4). not included in the proposal, presents possible limitations of interpretation of temporal and station to station results. Finally, a comprehensive summary of toxic organics in the sediments of the James River and certain tributarjes over a two-year period will be presented

    Polynuclear hydrocarbons in sediments and clams in the vicinity of a refinery outfall

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    The objectives of this study were: 1) to determine whether substances present in refinery process water are found in adjacent sediments and bivalves 2) to determine the concentrations of compounds detected 3) to identify compounds that may have adverse effects on marine animals or their human consumers

    Polynuclear hydrocarbons in sediments and clams in the vicinity of a refinery outfall

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    The objectives of this study were: 1) to determine whether certain organic substances (polynuclear aromatic hydrocarbons) present in a refinery process water are found in adjacent sediments and bivalves; and 2) to determine the concentrations of the compounds detected

    Hydrocarbon fuel chemistry : sediment water interaction

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    The objective of this program was to determine the effect of sediments on aqueous solutions of selected United States Air Force (USAF} hydrocarbon fuels. Effects of sediment type, organic carbon content, pH, temperature and salinity on interaction of dissolved hydrocarbons with sediment were studied. The results of this work can be used to estimate the role of sediment hydrocarbon interaction terms in fate models of aqueous systems, such as the Environmental Protection Agency EXAMS model

    The Present State of Organic Xenobiotics in the Chesapeake Bay - A Synthesis Paper

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    This manuscript discusses the results of the first two and one half years of a three-year study designed to determine the present state of xenobiotic compounds in the Chesapeake Bay. It shows that polynuclear aromatic hydrocarbons are the most frequently encountered compounds and are the most abundant. Concentrations are highest in the Northern Bay with several sources implicated. During this study an apparent dumping of the pesticide, DDT, occurred. Either the quantity disposed of was small enough or the assimulation capacity was large enough that no adverse effects were noted. The detection by us of 6-phenyldodecane in bottom sediments of the Patapsco River and its detection in a nearby industrial outfall by the Monsanto Research Corporation shows that chemicals entering the River can be dispersed throughout the system and can enter the Chesapeake Bay

    Neuroendocrine Disruption: More than Hormones are Upset

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    Only a small proportion of the published research on endocrine-disrupting chemicals (EDC) directly examined effects on neuroendocrine processes. There is an expanding body of evidence that anthropogenic chemicals exert effects on neuroendocrine systems and that these changes might impact peripheral organ systems and physiological processes. Neuroendocrine disruption extends the concept of endocrine disruption to include the full breadth of integrative physiology (i.e., more than hormones are upset). Pollutants may also disrupt numerous other neurochemical pathways to affect an animal's capacity to reproduce, develop and grow, or deal with stress and other challenges. Several examples are presented in this review, from both vertebrates and invertebrates, illustrating that diverse environmental pollutants including pharmaceuticals, organochlorine pesticides, and industrial contaminants have the potential to disrupt neuroendocrine control mechanisms. While most investigations on EDC are carried out with vertebrate models, an attempt is also made to highlight the importance of research on invertebrate neuroendocrine disruption. The neurophysiology of many invertebrates is well described and many of their neurotransmitters are similar or identical to those in vertebrates; therefore, lessons learned from one group of organisms may help us understand potential adverse effects in others. This review argues for the adoption of systems biology and integrative physiology to address the effects of EDC. Effects of pulp and paper mill effluents on fish reproduction are a good example of where relatively narrow hypothesis testing strategies (e.g., whether or not pollutants are sex steroid mimics) have only partially solved a major problem in environmental biology. It is clear that a global, integrative physiological approach, including improved understanding of neuroendocrine control mechanisms, is warranted to fully understand the impacts of pulp and paper mill effluents. Neuroendocrine disruptors are defined as pollutants in the environment that are capable of acting as agonists/antagonists or modulators of the synthesis and/or metabolism of neuropeptides, neurotransmitters, or neurohormones, which subsequently alter diverse physiological, behavioral, or hormonal processes to affect an animal's capacity to reproduce, develop and grow, or deal with stress and other challenges. By adopting a definition of neuroendocrine disruption that encompasses both direct physiological targets and their indirect downstream effects, from the level of the individual to the ecosystem, a more comprehensive picture of the consequences of environmentally relevant EDC exposure may emerge

    The EPA's human exposure research program for assessing cumulative risk in communities

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    Communities are faced with challenges in identifying and prioritizing environmental issues, taking actions to reduce their exposures, and determining their effectiveness for reducing human health risks. Additional challenges include determining what scientific tools are available and most relevant, and understanding how to use those tools; given these barriers, community groups tend to rely more on risk perception than science. The U.S. Environmental Protection Agency's Office of Research and Development, National Exposure Research Laboratory (NERL) and collaborators are developing and applying tools (models, data, methods) for enhancing cumulative risk assessments. The NERL's “Cumulative Communities Research Program” focuses on key science questions: (1) How to systematically identify and prioritize key chemical stressors within a given community?; (2) How to develop estimates of exposure to multiple stressors for individuals in epidemiologic studies?; and (3) What tools can be used to assess community-level distributions of exposures for the development and evaluation of the effectiveness of risk reduction strategies? This paper provides community partners and scientific researchers with an understanding of the NERL research program and other efforts to address cumulative community risks; and key research needs and opportunities. Some initial findings include the following: (1) Many useful tools exist for components of risk assessment, but need to be developed collaboratively with end users and made more comprehensive and user-friendly for practical application; (2) Tools for quantifying cumulative risks and impact of community risk reduction activities are also needed; (3) More data are needed to assess community- and individual-level exposures, and to link exposure-related information with health effects; and (4) Additional research is needed to incorporate risk-modifying factors (“non-chemical stressors”) into cumulative risk assessments. The products of this research program will advance the science for cumulative risk assessments and empower communities with information so that they can make informed, cost-effective decisions to improve public health

    Vulnerability as a Function of Individual and Group Resources in Cumulative Risk Assessment

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    BACKGROUND: The field of risk assessment has focused on protecting the health of individual people or populations of wildlife from single risks, mostly from chemical exposure. The U.S. Environmental Protection Agency recently began to address multiple risks to communities in the “Framework for Cumulative Risk Assessment” [EPA/630/P02/001F. Washington DC:Risk Assessment Forum, U.S. Environmental Protection Agency (2003)]. Simultaneously, several reports concluded that some individuals and groups are more vulnerable to environmental risks than the general population. However, vulnerability has received little specific attention in the risk assessment literature. OBJECTIVE: Our objective is to examine the issue of vulnerability in cumulative risk assessment and present a conceptual framework rather than a comprehensive review of the literature. In this article we consider similarities between ecologic and human communities and the factors that make communities vulnerable to environmental risks. DISCUSSION: The literature provides substantial evidence on single environmental factors and simple conditions that increase vulnerability or reduce resilience for humans and ecologic systems. This observation is especially true for individual people and populations of wildlife. Little research directly addresses the topic of vulnerability in cumulative risk situations, especially at the community level. The community level of organization has not been adequately considered as an end point in either human or ecologic risk assessment. Furthermore, current information on human risk does not completely explain the level of response in cumulative risk conditions. Ecologic risk situations are similarly more complex and unpredictable for cases of cumulative risk. CONCLUSIONS: Psychosocial conditions and responses are the principal missing element for humans. We propose a model for including psychologic and social factors as an integral component of cumulative risk assessment
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