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Sample records for block environmental toxic

  1. Environmental Justice (EJSCREEN) Block Group Data (USEPA)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EJSCREEN is an environmental justice (EJ) screening and mapping tool that provides EPA with a nationally consistent dataset and methodology for calculating "EJ...

  2. Investigating the Toxicity and Environmental Fate of Graphene Nanomaterials

    Science.gov (United States)

    The Hersam Laboratory at Northwestern University works with the Center for Environmental Implications of Nanotechnology and the United States Environmental Protection Agency to study the toxicity and environmental fate of emergent nanomaterials, specifically carbon-based nanomate...

  3. Environmental Factors, Toxicants and Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Anselm Mak

    2014-09-01

    Full Text Available Systemic lupus erythematosus (SLE is an immune-complex-mediated multi-systemic autoimmune condition of multifactorial etiology, which mainly affects young women. It is currently believed that the onset of SLE and lupus flares are triggered by various environmental factors in genetically susceptible individuals. Various environmental agents and toxicants, such as cigarette smoke, alcohol, occupationally- and non-occupationally-related chemicals, ultraviolet light, infections, sex hormones and certain medications and vaccines, have been implicated to induce SLE onset or flares in a number case series, case-control and population-based cohort studies and very few randomized controlled trials. Here, we will describe some of these recognized environmental lupus triggering and perpetuating factors and explain how these factors potentially bias the immune system towards autoimmunity through their interactions with genetic and epigenetic alterations. Further in-depth exploration of how potentially important environmental factors mechanistically interact with the immune system and the genome, which trigger the onset of SLE and lupus flares, will certainly be one of the plausible steps to prevent the onset and to decelerate the progress of the disease.

  4. Toxicity challenges in environmental chemicals: Prediction of ...

    Science.gov (United States)

    Physiologically based pharmacokinetic (PBPK) models bridge the gap between in vitro assays and in vivo effects by accounting for the adsorption, distribution, metabolism, and excretion of xenobiotics, which is especially useful in the assessment of human toxicity. Quantitative structure-activity relationships (QSAR) serve as a vital tool for the high-throughput prediction of chemical-specific PBPK parameters, such as the fraction of a chemical unbound by plasma protein (Fub). The presented work explores the merit of utilizing experimental pharmaceutical Fub data for the construction of a universal QSAR model, in order to compensate for the limited range of high-quality experimental Fub data for environmentally relevant chemicals, such as pollutants, pesticides, and consumer products. Independent QSAR models were constructed with three machine-learning algorithms, k nearest neighbors (kNN), random forest (RF), and support vector machine (SVM) regression, from a large pharmaceutical training set (~1000) and assessed with independent test sets of pharmaceuticals (~200) and environmentally relevant chemicals in the ToxCast program (~400). Small descriptor sets yielded the optimal balance of model complexity and performance, providing insight into the biochemical factors of plasma protein binding, while preventing over fitting to the training set. Overlaps in chemical space between pharmaceutical and environmental compounds were considered through applicability of do

  5. Hydroquinone: Environmental Pollution, Toxicity, and Microbial Answers

    Directory of Open Access Journals (Sweden)

    Francisco J. Enguita

    2013-01-01

    Full Text Available Hydroquinone is a major benzene metabolite, which is a well-known haematotoxic and carcinogenic agent associated with malignancy in occupational environments. Human exposure to hydroquinone can occur by dietary, occupational, and environmental sources. In the environment, hydroquinone showed increased toxicity for aquatic organisms, being less harmful for bacteria and fungi. Recent pieces of evidence showed that hydroquinone is able to enhance carcinogenic risk by generating DNA damage and also to compromise the general immune responses which may contribute to the impaired triggering of the host immune reaction. Hydroquinone bioremediation from natural and contaminated sources can be achieved by the use of a diverse group of microorganisms, ranging from bacteria to fungi, which harbor very complex enzymatic systems able to metabolize hydroquinone either under aerobic or anaerobic conditions. Due to the recent research development on hydroquinone, this review underscores not only the mechanisms of hydroquinone biotransformation and the role of microorganisms and their enzymes in this process, but also its toxicity.

  6. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  7. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  8. [Tetrabromobisphenol A - Toxicity, environmental and occupational exposures].

    Science.gov (United States)

    Jarosiewicz, Monika; Bukowska, Bożena

    2017-02-28

    Brominated flame retardants (BFR), including tetrabromobisphenol A (TBBPA) represents 25% of the global market of flame retardants. Among them, TBBPA is used on the largest scale (approx. 60%) because of its firebreak properties and widespread occurrence in every day products such as furniture, upholstery, adhesives and electronic equipment. A broad application of TBBPA can contribute to environmental pollution. Tetrabromobisphenol A has been determined in soil, water, river sediments and the atmosphere. Tetrabromobisphenol A is characterized by a high value of coefficient n-octanol/water (log P = 4.5), low acidity, and it may exist in undissociated or dissociated form. Due to the high hydrophobicity, TBBPA may accumulate in living organisms, including humans at different food chain levels. The occurrence of TBBPA in humans, e.g., in blood, fat tissue and mother milk, has been reported. Tetrabromobisphenol A is classified as hazard statements (H) H400/H410, which means that it is toxic to aquatic biota, causing long-term changes in these organisms. Up to now, only a few studies have been conducted to assess potential toxicity of high doses of TBBPA to mammals. Although many people are occupationally exposed to TBBPA during production or processing of this substance in their workplaces, there are only a few studies that have assessed the real hazard associated with TBPPA exposure. The aim of the study was to discuss the latest literature (mainly from the years 2010-2016) referring to the presence of TBBPA in the environment and its effects to living organisms. Data concerning occupational exposure to TBBPA were also presented. Med Pr 2017;68(1):121-134. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  9. Persistent Environmental Toxicants in Breast Milk and Rapid Infant Growth

    NARCIS (Netherlands)

    Criswell, Rachel; Lenters, Virissa; Mandal, Siddhartha; Stigum, Hein; Iszatt, Nina; Eggesbø, Merete

    2017-01-01

    BACKGROUND/AIMS: Many environmental toxicants are passed to infants in utero and through breast milk. Exposure to toxicants during the perinatal period can alter growth patterns, impairing growth or increasing obesity risk. Previous studies have focused on only a few toxicants at a time, which may

  10. Non-Markovianity in the collision model with environmental block

    Science.gov (United States)

    Jin, Jiasen; Yu, Chang-shui

    2018-05-01

    We present an extended collision model to simulate the dynamics of an open quantum system. In our model, the unit to represent the environment is, instead of a single particle, a block which consists of a number of environment particles. The introduced blocks enable us to study the effects of different strategies of system–environment interactions and states of the blocks on the non-Markovianities. We demonstrate our idea in the Gaussian channels of an all-optical system and derive a necessary and sufficient condition of non-Markovianity for such channels. Moreover, we show the equivalence of our criterion to the non-Markovian quantum jump in the simulation of the pure damping process of a single-mode field. We also show that the non-Markovianity of the channel working in the strategy that the system collides with environmental particles in each block in a certain order will be affected by the size of the block and the embedded entanglement and the effects of heating and squeezing the vacuum environmental state will quantitatively enhance the non-Markovianity.

  11. Toxic plasma concentration of ropivacaine after a paravertebral block in a patient suffering from severe hypoalbuminemia.

    Science.gov (United States)

    Calenda, Emile; Baste, Jean Marc; Hajjej, Ridha; Danielou, Eric; Peillon, Christophe

    2014-03-01

    A case of systemic ropivacaine toxicity from a continuous thoracic paravertebral block in an adult patient who received a lobectomy is presented. The catheter was placed by the surgeon. Eleven hours after the start of the infusion, the patient experienced an arrhythmia leading to death. The total venous plasma concentration of ropivacaine was high (3.2 μg/mL). Furthermore, the patient had severe hypoalbuminemia (albumin 24 g/L), which resulted in the increase of the unbound ropivacaine plasma concentration that was responsible for the toxic side effects. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Enrichment with Wood Blocks Does Not Affect Toxicity Assessment in an Exploratory Toxicology Model Using Sprague–Dawley Rats

    Science.gov (United States)

    Ditewig, Amy C; Bratcher, Natalie A; Davila, Donna R; Dayton, Brian D; Ebert, Paige; Lesuisse, Philippe; Liguori, Michael J; Wetter, Jill M; Yang, Hyuna; Buck, Wayne R

    2014-01-01

    Environmental enrichment in rodents may improve animal well-being but can affect neurologic development, immune system function, and aging. We tested the hypothesis that wood block enrichment affects the interpretation of traditional and transcriptomic endpoints in an exploratory toxicology testing model using a well-characterized reference compound, cyclophosphamide. ANOVA was performed to distinguish effects of wood block enrichment separate from effects of 40 mg/kg cyclophosphamide treatment. Biologically relevant and statistically significant effects of wood block enrichment occurred only for body weight gain. ANOVA demonstrated the expected effects of cyclophosphamide on food consumption, spleen weight, and hematology. According to transcriptomic endpoints, cyclophosphamide induced fewer changes in gene expression in liver than in spleen. Splenic transcriptomic pathways affected by cyclophosphamide included: iron hemostasis; vascular tissue angiotensin system; hepatic stellate cell activation and fibrosis; complement activation; TGFβ-induced hypertrophy and fibrosis; monocytes, macrophages, and atherosclerosis; and platelet activation. Changes in these pathways due to cyclophosphamide treatment were consistent with bone marrow toxicity regardless of enrichment. In a second study, neither enrichment nor type of cage flooring altered body weight or food consumption over a 28-d period after the first week. In conclusion, wood block enrichment did not interfere with a typical exploratory toxicology study; the effects of ingested wood on drug level kinetics may require further consideration. PMID:24827566

  13. Thermoregulatory responses to environmental toxicants: The interaction of thermal stress and toxicant exposure

    International Nuclear Information System (INIS)

    Leon, Lisa R.

    2008-01-01

    Thermal stress can have a profound impact on the physiological responses that are elicited following environmental toxicant exposure. The efficacy by which toxicants enter the body is directly influenced by thermoregulatory effector responses that are evoked in response to high ambient temperatures. In mammals, the thermoregulatory response to heat stress consists of an increase in skin blood flow and moistening of the skin surface to dissipate core heat to the environment. These physiological responses may exacerbate chemical toxicity due to increased permeability of the skin, which facilitates the cutaneous absorption of many environmental toxicants. The core temperature responses that are elicited in response to high ambient temperatures, toxicant exposure or both can also have a profound impact on the ability of an organism to survive the insult. In small rodents, the thermoregulatory response to thermal stress and many environmental toxicants (such as organophosphate compounds) is often biphasic in nature, consisting initially of a regulated reduction in core temperature (i.e., hypothermia) followed by fever. Hypothermia is an important thermoregulatory survival strategy that is used by small rodents to diminish the effect of severe environmental insults on tissue homeostasis. The protective effect of hypothermia is realized by its effects on chemical toxicity as molecular and cellular processes, such as lipid peroxidation and the formation of reactive oxygen species, are minimized at reduced core temperatures. The beneficial effects of fever are unknown under these conditions. Perspective is provided on the applicability of data obtained in rodent models to the human condition

  14. Prenatal imprinting by environmental toxicants: really an important issue?

    Directory of Open Access Journals (Sweden)

    Karl Ernst v. Mühlendahl

    2015-06-01

    Full Text Available Prenatal imprinting of sexual behaviour and of other traits by environmental toxicants has been one important topic in the ongoing discussions in environmental medicine. This review of the literature shows that, so far, concrete data are sparse and, in part, contradictory.

  15. Cellular Models for Environmental Toxicant Biomarker Discovery

    National Research Council Canada - National Science Library

    Halverson, Kelly M; Lewsis, John A; Jackson, David A; Dennis, William; Brennan, Linda; Krakaner, Teresa

    2006-01-01

    ...) is the development of biomarkers of exposure, effect, and susceptibility. As exposure monitoring using environmental sampling equipment can be impractical and doesn't account for differences in individual responses, new methodologies must be sought...

  16. Environmental Mercury and Its Toxic Effects

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2014-03-01

    Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

  17. The toll of toxics: investigating environmental contaminants

    Science.gov (United States)

    Sparling, Donald W.; Rattner, Barnett A.; Barclay, John S.

    2010-01-01

    On Earth Day of this year, the British Petroleum-operated Deepwater Horizon oil drilling rig exploded in the Gulf of Mexico, 41 miles off the Louisiana coast. The blast killed 11 workers, injured 17, launched a massive oil spill, and triggered an environmental catastrophe—the full impact of which may not be realized for years.

  18. Assessing reproductive toxicity of two environmental toxicants with a novel in vitro human spermatogenic model

    Directory of Open Access Journals (Sweden)

    Charles A. Easley, IV

    2015-05-01

    Full Text Available Environmental influences and insults by reproductive toxicant exposure can lead to impaired spermatogenesis or infertility. Understanding how toxicants disrupt spermatogenesis is critical for determining how environmental factors contribute to impaired fertility. While current animal models are available, understanding of the reproductive toxic effects on human fertility requires a more robust model system. We recently demonstrated that human pluripotent stem cells can differentiate into spermatogonial stem cells/spermatogonia, primary and secondary spermatocytes, and haploid spermatids; a model that mimics many aspects of human spermatogenesis. Here, using this model system, we examine the effects of 2-bromopropane (2-BP and 1,2,dibromo-3-chloropropane (DBCP on in vitro human spermatogenesis. 2-BP and DBCP are non-endocrine disrupting toxicants that are known to impact male fertility. We show that acute treatment with either 2-BP or DBCP induces a reduction in germ cell viability through apoptosis. 2-BP and DBCP affect viability of different cell populations as 2-BP primarily reduces spermatocyte viability, whereas DBCP exerts a much greater effect on spermatogonia. Acute treatment with 2-BP or DBCP also reduces the percentage of haploid spermatids. Both 2-BP and DBCP induce reactive oxygen species (ROS formation leading to an oxidized cellular environment. Taken together, these results suggest that acute exposure with 2-BP or DBCP causes human germ cell death in vitro by inducing ROS formation. This system represents a unique platform for assessing human reproductive toxicity potential of various environmental toxicants in a rapid, efficient, and unbiased format.

  19. Environmentally induced epigenetic toxicity: potential public health concerns.

    Science.gov (United States)

    Marczylo, Emma L; Jacobs, Miriam N; Gant, Timothy W

    2016-09-01

    Throughout our lives, epigenetic processes shape our development and enable us to adapt to a constantly changing environment. Identifying and understanding environmentally induced epigenetic change(s) that may lead to adverse outcomes is vital for protecting public health. This review, therefore, examines the present understanding of epigenetic mechanisms involved in the mammalian life cycle, evaluates the current evidence for environmentally induced epigenetic toxicity in human cohorts and rodent models and highlights the research considerations and implications of this emerging knowledge for public health and regulatory toxicology. Many hundreds of studies have investigated such toxicity, yet relatively few have demonstrated a mechanistic association among specific environmental exposures, epigenetic changes and adverse health outcomes in human epidemiological cohorts and/or rodent models. While this small body of evidence is largely composed of exploratory in vivo high-dose range studies, it does set a precedent for the existence of environmentally induced epigenetic toxicity. Consequently, there is worldwide recognition of this phenomenon, and discussion on how to both guide further scientific research towards a greater mechanistic understanding of environmentally induced epigenetic toxicity in humans, and translate relevant research outcomes into appropriate regulatory policies for effective public health protection.

  20. The Industrial Toxics Project: Targeting chemicals for environmental results

    International Nuclear Information System (INIS)

    Burch, W.M.

    1991-01-01

    In September, 1990, the Administrator of the US Environmental Protection Agency committed the Agency to a program of targeting chemicals for multi-media risk reduction activities through pollution prevention. The Industrial Toxics Project will place emphasis on obtaining voluntary commitments from industry to reduce releases of toxic chemicals to the air, water, and land with a goal of reducing releases nationwide by 33% by 1992 and 50% by 1995. An initial list of 18 chemicals have been selected based on recommendations from each Agency program. The chemicals selected are subject to reporting under the Toxic Chemical Release Inventory Program which will provide the basis for tracking progress. The chemicals are characterized by high production volume, toxicity and releases and present the potential for significant risk reduction through pollution prevention. This presentation will discuss the focus and direction of this new initiative

  1. Neurodevelopmental Disorders and Environmental Toxicants: Epigenetics as an Underlying Mechanism

    Directory of Open Access Journals (Sweden)

    Nguyen Quoc Vuong Tran

    2017-01-01

    Full Text Available The increasing prevalence of neurodevelopmental disorders, especially autism spectrum disorders (ASD and attention deficit hyperactivity disorder (ADHD, calls for more research into the identification of etiologic and risk factors. The Developmental Origin of Health and Disease (DOHaD hypothesizes that the environment during fetal and childhood development affects the risk for many chronic diseases in later stages of life, including neurodevelopmental disorders. Epigenetics, a term describing mechanisms that cause changes in the chromosome state without affecting DNA sequences, is suggested to be the underlying mechanism, according to the DOHaD hypothesis. Moreover, many neurodevelopmental disorders are also related to epigenetic abnormalities. Experimental and epidemiological studies suggest that exposure to prenatal environmental toxicants is associated with neurodevelopmental disorders. In addition, there is also evidence that environmental toxicants can result in epigenetic alterations, notably DNA methylation. In this review, we first focus on the relationship between neurodevelopmental disorders and environmental toxicants, in particular maternal smoking, plastic-derived chemicals (bisphenol A and phthalates, persistent organic pollutants, and heavy metals. We then review studies showing the epigenetic effects of those environmental factors in humans that may affect normal neurodevelopment.

  2. Neurodevelopmental Disorders and Environmental Toxicants: Epigenetics as an Underlying Mechanism

    Science.gov (United States)

    2017-01-01

    The increasing prevalence of neurodevelopmental disorders, especially autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD), calls for more research into the identification of etiologic and risk factors. The Developmental Origin of Health and Disease (DOHaD) hypothesizes that the environment during fetal and childhood development affects the risk for many chronic diseases in later stages of life, including neurodevelopmental disorders. Epigenetics, a term describing mechanisms that cause changes in the chromosome state without affecting DNA sequences, is suggested to be the underlying mechanism, according to the DOHaD hypothesis. Moreover, many neurodevelopmental disorders are also related to epigenetic abnormalities. Experimental and epidemiological studies suggest that exposure to prenatal environmental toxicants is associated with neurodevelopmental disorders. In addition, there is also evidence that environmental toxicants can result in epigenetic alterations, notably DNA methylation. In this review, we first focus on the relationship between neurodevelopmental disorders and environmental toxicants, in particular maternal smoking, plastic-derived chemicals (bisphenol A and phthalates), persistent organic pollutants, and heavy metals. We then review studies showing the epigenetic effects of those environmental factors in humans that may affect normal neurodevelopment. PMID:28567415

  3. Technologies for environmental cleanup: Toxic and hazardous waste management

    International Nuclear Information System (INIS)

    Ragaini, R.C.

    1993-12-01

    This is the second in a series of EUROCOURSES conducted under the title, ''Technologies for Environmental Cleanup.'' To date, the series consist of the following courses: 1992, soils and groundwater; 1993, Toxic and Hazardous Waste Management. The 1993 course focuses on recent technological developments in the United States and Europe in the areas of waste management policies and regulations, characterization and monitoring of waste, waste minimization and recycling strategies, thermal treatment technologies, photolytic degradation processes, bioremediation processes, medical waste treatment, waste stabilization processes, catalytic organic destruction technologies, risk analyses, and data bases and information networks. It is intended that this course ill serve as a resource of state-of-the-art technologies and methodologies for the environmental protection manager involved in decisions concerning the management of toxic and hazardous waste

  4. Breathless: Schools, Air Toxics, and Environmental Justice in California

    OpenAIRE

    2005-01-01

    Recent legislation on both federal and state levels has placed the intersection between children’s health and environmental justice on the forefront of public policy debate. This study looks at the intersection of air quality, children’s health, and school performance in the context of environmental equity in California. Information from the U.S. EPA’s National Air Toxics Assessment (NATA) is used to calculate a respiratory hazard ratio for each of California’s census tracts. These ratios ar...

  5. Porphyrinuria in childhood autistic disorder: Implications for environmental toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Nataf, Robert [Laboratoire Philippe Auguste, Paris (France); Skorupka, Corinne [Association ARIANE, Clichy (France); Amet, Lorene [Association ARIANE, Clichy (France); Lam, Alain [Laboratoire Philippe Auguste, Paris (France); Springbett, Anthea [Department of Statistics, Roslin Institute, Roslin (United Kingdom); Lathe, Richard [Pieta Research, PO Box 27069, Edinburgh EH10 5YW (United Kingdom)

    2006-07-15

    To address a possible environmental contribution to autism, we carried out a retrospective study on urinary porphyrin levels, a biomarker of environmental toxicity, in 269 children with neurodevelopmental and related disorders referred to a Paris clinic (2002-2004), including 106 with autistic disorder. Urinary porphyrin levels determined by high-performance liquid chromatography were compared between diagnostic groups including internal and external control groups. Coproporphyrin levels were elevated in children with autistic disorder relative to control groups. Elevation was maintained on normalization for age or to a control heme pathway metabolite (uroporphyrin) in the same samples. The elevation was significant (P < 0.001). Porphyrin levels were unchanged in Asperger's disorder, distinguishing it from autistic disorder. The atypical molecule precoproporphyrin, a specific indicator of heavy metal toxicity, was also elevated in autistic disorder (P < 0.001) but not significantly in Asperger's. A subgroup with autistic disorder was treated with oral dimercaptosuccinic acid (DMSA) with a view to heavy metal removal. Following DMSA there was a significant (P = 0.002) drop in urinary porphyrin excretion. These data implicate environmental toxicity in childhood autistic disorder.

  6. Porphyrinuria in childhood autistic disorder: Implications for environmental toxicity

    International Nuclear Information System (INIS)

    Nataf, Robert; Skorupka, Corinne; Amet, Lorene; Lam, Alain; Springbett, Anthea; Lathe, Richard

    2006-01-01

    To address a possible environmental contribution to autism, we carried out a retrospective study on urinary porphyrin levels, a biomarker of environmental toxicity, in 269 children with neurodevelopmental and related disorders referred to a Paris clinic (2002-2004), including 106 with autistic disorder. Urinary porphyrin levels determined by high-performance liquid chromatography were compared between diagnostic groups including internal and external control groups. Coproporphyrin levels were elevated in children with autistic disorder relative to control groups. Elevation was maintained on normalization for age or to a control heme pathway metabolite (uroporphyrin) in the same samples. The elevation was significant (P < 0.001). Porphyrin levels were unchanged in Asperger's disorder, distinguishing it from autistic disorder. The atypical molecule precoproporphyrin, a specific indicator of heavy metal toxicity, was also elevated in autistic disorder (P < 0.001) but not significantly in Asperger's. A subgroup with autistic disorder was treated with oral dimercaptosuccinic acid (DMSA) with a view to heavy metal removal. Following DMSA there was a significant (P = 0.002) drop in urinary porphyrin excretion. These data implicate environmental toxicity in childhood autistic disorder

  7. Inter-individual susceptibility to environmental toxicants-A current assessment

    International Nuclear Information System (INIS)

    Nebert, Daniel W.

    2005-01-01

    Virtually all diseases have an environmental component. The two most important factors affecting your unique risk of an environmental disease (toxicity or cancer) are (a) your exposure to the environmental agent and (b) your genes. Epidemiologists have found ways to calculate inter-individual risk-if the exposure to environmental agents is sufficiently high and can be documented (e.g., years of cigarette smoking, taking prescribed drugs, drinking alcohol, or exposure to radon or other radioactive material, etc.). If the dose of environmental agents is lower and more ambiguous (e.g., exposure to chemicals on the job, herbicides sprayed on a golf course, outdoor or indoor air pollution, endocrine disruptors in cans of food, living near a toxic waste dump site, etc.), however, calculations of inter-individual risk become much more difficult. Highly accurate DNA tests for genetic susceptibility to toxicity and cancer have been sought in order to identify individuals at increased risk; this type of research represents the leading edge of phenotype-genotype association studies and is the major goal of most public health and preventive medicine programs. The task, however, has turned out to be far more challenging than anticipated. The major stumbling block has been the difficulty in determining an unequivocal phenotype or an unequivocal genotype. We were quite optimistic 5-10 years ago that this would be easy, but now we are beginning to appreciate how difficult it is to determine an unequivocal phenotype or genotype with certainty. For many reasons set forth in this overview, it appears that DNA testing alone, to predict and prevent environmental disease on an individual basis, may be virtually impossible with current knowledge and technologies and will require novel insights before major practical applications will evolve

  8. Potential Environmental Justice Areas - (EJSCREEN) Block Group Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data are from EJSCREEN, an environmental justice (EJ) screening and mapping tool that provides EPA with a nationally consistent dataset and methodology for...

  9. Acute ecological toxicity and environmental persistence of simulants

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Ligotke, M.W.; McVeety, B.D.; Fellows, R.J.; Bolton, H. Jr.; Li, S.W.; Van Voris, P.; Wentsel, R.S.

    1988-06-01

    The objectives of these studies are to establish the comparative environmental behavior and chemical fate of chemical simulants. Laboratory studies were undertaken to establish: (1) deposition efficiency (deposition velocities, Vd) for receptor surfaces including plant foliage and soils; (2) dose/response relationships for important environmental components including plants and soil microflora; and (3) the environmental persistence of the simulants. Chemical agent simulants are employed for a range of testing and training activities where use of chemical agents is less than suitable from a safety and environmental standpoint. A variety of chemical simulant materials are used to simulate either nerve agents or blister agents. The following research describes the environmental effects and persistence of four simulants. These are the nerve agent stimulants diisopropyl methylphosphonate (DIMP), diisopropyl fluorophosphate (DFP), and bis (2-ethylhexyl) phosphonate (BIS), and the mustard stimulant 2-chloroethyl ethyl sulfide (CEES). The vapor pressures for DIMP, DFP, and CEES are relatively high, reported to be 0.17, 0.58 and 3.4 mm Hg, respectively; while that of BIS is substantially less at 5.8 /times/ 10/sup /minus/5/ mm Hg at 25/degree/C. The chemical characteristics of DFP and CEES are very similar to G/VX-agents and mustard, respectively, and are employed for materials evaluation under controlled conditions. However, their toxicity precludes their use in the environment. DIMP and BIS are currently used for testing in the open air. 3 figs., 3 tabs.

  10. Evaluation of Environmental and Hydraulic Performance of Bio-Composite Revetment Blocks

    OpenAIRE

    Thamer A.  Ahmeed; Nor A.  Alias; Abdul H.  Ghazali; Mohd. S.  Jaafar

    2006-01-01

    It is necessary to develop a concrete revetment block which can cater for environment and at the same time it will be effective in protecting river banks (stabilize the slope of banks) from scouring during flood. In the present study, the environmental and hydraulic performance of the proposed revetment block was evaluated through laboratory and field tests. The tested revetment block is called bio-composite because it is composed of concrete, plastic mesh and biological material (coconut hus...

  11. Persistent Environmental Toxicants in Breast Milk and Rapid Infant Growth.

    Science.gov (United States)

    Criswell, Rachel; Lenters, Virissa; Mandal, Siddhartha; Stigum, Hein; Iszatt, Nina; Eggesbø, Merete

    2017-01-01

    Many environmental toxicants are passed to infants in utero and through breast milk. Exposure to toxicants during the perinatal period can alter growth patterns, impairing growth or increasing obesity risk. Previous studies have focused on only a few toxicants at a time, which may confound results. We investigated levels of 26 toxicants in breast milk and their associations with rapid infant growth, a risk factor for later obesity. We used data from the Norwegian HUMIS study, a multi-center cohort of 2,606 mothers and newborns enrolled between 2002 and 2008. Milk samples collected 1 month after delivery from a subset of 789 women oversampled by overweight were analyzed for toxicants including polychlorinated biphenyls (PCBs), heavy metals, and pesticides. Growth was defined as change in weight-for-age z-score between 0 and 6 months among the HUMIS population, and rapid growth was defined as change in z-score above 0.67. We used a Bayesian variable selection method to determine the exposures that most explained variation in the outcome. Identified toxicants were included in logistic and linear regression models to estimate associations with growth, adjusting for maternal age, smoking, education, pre-pregnancy body mass index (BMI), gestational weight gain, parity, child sex, cumulative breastfeeding, birth weight, gestational age, and preterm status. Of 789 infants, 19.2% displayed rapid growth. The median maternal age was 29.6 years, and the median pre-pregnancy BMI was 24.0 kg/m2, with 45.3% of mothers overweight or obese. Rapid growers were more likely to be firstborn. Hexachlorobenzene, β-hexachlorocyclohexane (β-HCH), and PCB-74 were identified in the variable selection method. An interquartile range (IQR) increase in β-HCH exposure was associated with a lower odds of rapid growth (OR 0.63, 95% CI 0.42-0.94). Newborns exposed to high levels of β-HCH showed reduced infant growth (β = -0.03, 95% CI -0.05 to -0.01 for IQR increase in breast milk concentration

  12. Nanoparticles: Their potential toxicity, waste and environmental management

    International Nuclear Information System (INIS)

    Bystrzejewska-Piotrowska, Grazyna; Golimowski, Jerzy; Urban, Pawel L.

    2009-01-01

    This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties - not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amara's law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.

  13. Environmental toxicity and radioactivity assessment of a titanium-processing residue with potential for environmental use.

    Science.gov (United States)

    Wendling, Laura A; Binet, Monique T; Yuan, Zheng; Gissi, Francesca; Koppel, Darren J; Adams, Merrin S

    2013-07-01

    Thorough examination of the physicochemical characteristics of a Ti-processing residue was undertaken, including mineralogical, geochemical, and radiochemical characterization, and an investigation of the environmental toxicity of soft-water leachate generated from the residue. Concentrations of most metals measured in the leachate were low; thus, the residue is unlikely to leach high levels of potentially toxic elements on exposure to low-ionic strength natural waters. Relative to stringent ecosystem health-based guidelines, only chromium concentrations in the leachate exceeded guideline concentrations for 95% species protection; however, sulfate was present at concentrations known to cause toxicity. It is likely that the high concentration of calcium and extreme water hardness of the leachate reduced the bioavailability of some elements. Geochemical modeling of the leachate indicated that calcium and sulfate concentrations were largely controlled by gypsum mineral dissolution. The leachate was not toxic to the microalga Chlorella sp., the cladoceran Ceriodaphnia dubia, or the estuarine bacterium Vibrio fischeri. The Ti-processing residue exhibited an absorbed dose rate of 186 nGy/h, equivalent to an annual dose of 1.63 mGy and an annual effective dose of 0.326 mGy. In summary, the results indicate that the Ti-processing residue examined is suitable for productive use as an environmental amendment following 10 to 100 times dilution to ameliorate potential toxic effects due to chromium or sulfate. Copyright © 2013 SETAC.

  14. Linking ‘toxic outliers’ to environmental justice communities

    International Nuclear Information System (INIS)

    Collins, Mary B; Munoz, Ian; JaJa, Joseph

    2016-01-01

    Several key studies have found that a small minority of producers, polluting at levels far exceeding group averages, generate the majority of overall exposure to industrial toxics. Frequently, such patterns go unnoticed and are understudied outside of the academic community. To our knowledge, no research to date has systematically described the scope and extent of extreme variations in industrially based exposure estimates and sought to link inequities in harm produced to inequities in exposure. In an analysis of all permitted industrial facilities across the United States, we show that there exists a class of hyper-polluters—the worst-of-the-worst—that disproportionately expose communities of color and low income populations to chemical releases. This study hopes to move beyond a traditional environmental justice research frame, bringing new computational methods and perspectives aimed at the empirical study of societal power dynamics. Our findings suggest the possibility that substantial environmental gains may be made through selective environmental enforcement, rather than sweeping initiatives. (letter)

  15. Bidding for blocks and environmental control; Licitacao de blocos e o controle ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Agostinho, Magila Maria [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Faculdade de Direito; Silveira Neto, Otacilio dos Santos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Recursos Humanos da ANP em Direito do Petroleo e Gas Natural, PRH-36

    2004-07-01

    With the coming of the Constitutional Emend n. 9/95, the Brazilian market of oil and natural gas stopped being monopolized by PETROBRAS. Since then, the concession of blocks began to be preceded by the public tender procedure realized by ANP- National Agency of Oil. The activities of oil exploration and production are potentially damaging to environment, what brings necessary the environmental licence and the previous study of the environmental impacts caused in this activity. Considering that the environmental licence must be done after the tender process, the enterprises that bought the blocks would assume the risk of not being allowed to practice their activities because of the absence of the environmental licence. To avoid that the It's offered blocks in not viable areas for oil exploration, the ANP, responsible for the public tender must accomplish a previous environmental control, to assure to the enterprises involved the environmental viability of the blocks offered. This project will touch the question of how has been realized the previous environmental control of the blocks offered by ANP into the public tender process, detaching, the control done at the 6. Round. (author)

  16. The neuronal nitric oxide synthase inhibitor NANT blocks acetaminophen toxicity and protein nitration in freshly isolated hepatocytes.

    Science.gov (United States)

    Banerjee, Sudip; Melnyk, Stepan B; Krager, Kimberly J; Aykin-Burns, Nukhet; Letzig, Lynda G; James, Laura P; Hinson, Jack A

    2015-12-01

    3-Nitrotyrosine (3NT) in liver proteins of mice treated with hepatotoxic doses of acetaminophen (APAP) has been postulated to be causative in toxicity. Nitration is by a reactive nitrogen species formed from nitric oxide (NO). The source of the NO is unclear. iNOS knockout mice were previously found to be equally susceptible to APAP toxicity as wildtype mice and iNOS inhibitors did not decrease toxicity in mice or in hepatocytes. In this work we examined the potential role of nNOS in APAP toxicity in hepatocytes using the specific nNOS inhibitor NANT (10 µM)(N-[(4S)-4-amino-5-[(2-aminoethyl)amino]pentyl]-N'-nitroguanidinetris (trifluoroacetate)). Primary hepatocytes (1 million/ml) from male B6C3F1 mice were incubated with APAP (1mM). Cells were removed and assayed spectrofluorometrically for reactive nitrogen and oxygen species using diaminofluorescein (DAF) and Mitosox red, respectively. Cytotoxicity was determined by LDH release into media. Glutathione (GSH, GSSG), 3NT, GSNO, acetaminophen-cysteine adducts, NAD, and NADH were measured by HPLC. APAP significantly increased cytotoxicity at 1.5-3.0 h. The increase was blocked by NANT. NANT did not alter APAP mediated GSH depletion or acetaminophen-cysteine adducts in proteins which indicated that NANT did not inhibit metabolism. APAP significantly increased spectroflurometric evidence of reactive nitrogen and oxygen formation at 0.5 and 1.0 h, respectively, and increased 3NT and GSNO at 1.5-3.0 h. These increases were blocked by NANT. APAP dramatically increased NADH from 0.5-3.0 h and this increase was blocked by NANT. Also, APAP decreased the Oxygen Consumption Rate (OCR), decreased ATP production, and caused a loss of mitochondrial membrane potential, which were all blocked by NANT. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Tetrabromobisphenol A – Toxicity, environmental and occupational exposures

    Directory of Open Access Journals (Sweden)

    Monika Jarosiewicz

    2017-02-01

    Full Text Available Brominated flame retardants (BFR, including tetrabromobisphenol A (TBBPA represents 25% of the global market of flame retardants. Among them, TBBPA is used on the largest scale (approx. 60% because of its firebreak properties and widespread occurrence in every day products such as furniture, upholstery, adhesives and electronic equipment. A broad application of TBBPA can contribute to environmental pollution. Tetrabromobisphenol A has been determined in soil, water, river sediments and the atmosphere. Tetrabromobisphenol A is characterized by a high value of coefficient n-octanol/water (log P = 4.5, low acidity, and it may exist in undissociated or dissociated form. Due to the high hydrophobicity, TBBPA may accumulate in living organisms, including humans at different food chain levels. The occurrence of TBBPA in humans, e.g., in blood, fat tissue and mother milk, has been reported. Tetrabromobisphenol A is classified as hazard statements (H H400/H410, which means that it is toxic to aquatic biota, causing long-term changes in these organisms. Up to now, only a few studies have been conducted to assess potential toxicity of high doses of TBBPA to mammals. Although many people are occupationally exposed to TBBPA during production or processing of this substance in their workplaces, there are only a few studies that have assessed the real hazard associated with TBPPA exposure. The aim of the study was to discuss the latest literature (mainly from the years 2010–2016 referring to the presence of TBBPA in the environment and its effects to living organisms. Data concerning occupational exposure to TBBPA were also presented. Med Pr 2017;68(1:121–134

  18. Potential hazard by toxic substances in foods. Environmental protection

    Energy Technology Data Exchange (ETDEWEB)

    Unterhalt, B

    1974-01-01

    This paper reviews various toxic substances found in foods. These toxic substances include not only natural occurring toxins but also bacterial food poisons, pesticide residues, heavy metals, and food additives. The potential hazard of each toxic substance is discussed. 74 references.

  19. A novel exploratory chemometric approach to environmental monitorring by combining block clustering with Partial Least Square (PLS) analysis

    Science.gov (United States)

    2013-01-01

    Background Given the serious threats posed to terrestrial ecosystems by industrial contamination, environmental monitoring is a standard procedure used for assessing the current status of an environment or trends in environmental parameters. Measurement of metal concentrations at different trophic levels followed by their statistical analysis using exploratory multivariate methods can provide meaningful information on the status of environmental quality. In this context, the present paper proposes a novel chemometric approach to standard statistical methods by combining the Block clustering with Partial least square (PLS) analysis to investigate the accumulation patterns of metals in anthropized terrestrial ecosystems. The present study focused on copper, zinc, manganese, iron, cobalt, cadmium, nickel, and lead transfer along a soil-plant-snai food chain, and the hepatopancreas of the Roman snail (Helix pomatia) was used as a biological end-point of metal accumulation. Results Block clustering deliniates between the areas exposed to industrial and vehicular contamination. The toxic metals have similar distributions in the nettle leaves and snail hepatopancreas. PLS analysis showed that (1) zinc and copper concentrations at the lower trophic levels are the most important latent factors that contribute to metal accumulation in land snails; (2) cadmium and lead are the main determinants of pollution pattern in areas exposed to industrial contamination; (3) at the sites located near roads lead is the most threatfull metal for terrestrial ecosystems. Conclusion There were three major benefits by applying block clustering with PLS for processing the obtained data: firstly, it helped in grouping sites depending on the type of contamination. Secondly, it was valuable for identifying the latent factors that contribute the most to metal accumulation in land snails. Finally, it optimized the number and type of data that are best for monitoring the status of metallic

  20. A novel exploratory chemometric approach to environmental monitorring by combining block clustering with Partial Least Square (PLS) analysis.

    Science.gov (United States)

    Nica, Dragos V; Bordean, Despina Maria; Pet, Ioan; Pet, Elena; Alda, Simion; Gergen, Iosif

    2013-08-30

    Given the serious threats posed to terrestrial ecosystems by industrial contamination, environmental monitoring is a standard procedure used for assessing the current status of an environment or trends in environmental parameters. Measurement of metal concentrations at different trophic levels followed by their statistical analysis using exploratory multivariate methods can provide meaningful information on the status of environmental quality. In this context, the present paper proposes a novel chemometric approach to standard statistical methods by combining the Block clustering with Partial least square (PLS) analysis to investigate the accumulation patterns of metals in anthropized terrestrial ecosystems. The present study focused on copper, zinc, manganese, iron, cobalt, cadmium, nickel, and lead transfer along a soil-plant-snai food chain, and the hepatopancreas of the Roman snail (Helix pomatia) was used as a biological end-point of metal accumulation. Block clustering deliniates between the areas exposed to industrial and vehicular contamination. The toxic metals have similar distributions in the nettle leaves and snail hepatopancreas. PLS analysis showed that (1) zinc and copper concentrations at the lower trophic levels are the most important latent factors that contribute to metal accumulation in land snails; (2) cadmium and lead are the main determinants of pollution pattern in areas exposed to industrial contamination; (3) at the sites located near roads lead is the most threatfull metal for terrestrial ecosystems. There were three major benefits by applying block clustering with PLS for processing the obtained data: firstly, it helped in grouping sites depending on the type of contamination. Secondly, it was valuable for identifying the latent factors that contribute the most to metal accumulation in land snails. Finally, it optimized the number and type of data that are best for monitoring the status of metallic contamination in terrestrial ecosystems

  1. A systematic review on the role of environmental toxicants in stem cells aging.

    Science.gov (United States)

    Hodjat, Mahshid; Rezvanfar, Mohammad Amin; Abdollahi, Mohammad

    2015-12-01

    Stem cells are an important target for environmental toxicants. As they are the main source for replenishing of organs in the body, any changes in their normal function could affect the regenerative potential of organs, leading to the appearance of age-related disease and acceleration of the aging process. Environmental toxicants could exert their adverse effect on stem cell function via multiple cellular and molecular mechanisms, resulting in changes in the stem cell differentiation fate and cell transformation, and reduced self-renewal capacity, as well as induction of stress-induced cellular senescence. The present review focuses on the effect of environmental toxicants on stem cell function associated with the aging process. We categorized environmental toxicants according to their preferred molecular mechanism of action on stem cells, including changes in genomic, epigenomic, and proteomic levels and enhancing oxidative stress. Pesticides, tobacco smoke, radiation and heavy metals are well-studied toxicants that cause stem cell dysfunction via induction of oxidative stress. Transgenerational epigenetic changes are the most important effects of a variety of toxicants on germ cells and embryos that are heritable and could affect health in the next several generations. A better understanding of the underlying mechanisms of toxicant-induced stem cell aging will help us to develop therapeutic intervention strategies against environmental aging. Meanwhile, more efforts are required to find the direct in vivo relationship between adverse effect of environmental toxicants and stem cell aging, leading to organismal aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Dataset on usnic acid from Cladonia substellata Vainio (Lichen) schistosomiasis mansoni's vector control and environmental toxicity.

    Science.gov (United States)

    Andrade de Araújo, Hallysson Douglas; Dos Santos Silva, Luanna Ribeiro; de Siqueira, Williams Nascimento; Martins da Fonseca, Caíque Silveira; da Silva, Nicácio Henrique; de Albuquerque Melo, Ana Maria Mendonça; Barroso Martins, Mônica Cristina; de Menezes Lima, Vera Lúcia

    2018-04-01

    This text presents complementary data corresponding to schistosomiasis mansoni's vector control and enviromental toxicity using usnic acid. These informations support our research article "Toxicity of Usnic Acid from Cladonia substellata (Lichen) to embryos and adults of Biomphalaria glabrata " by Araújo et al. [1], and focuses on the analysis of the detailed data regarding the different concentrations of Usnic Acid and their efficiency to B. glabrata mortality and non-viability, as also to environmental toxicity, evaluated by A. salina mortality.

  3. Is the OECD acute worm toxicity test environmentally relevant? The effect of mineral form on calculated lead toxicity

    International Nuclear Information System (INIS)

    Davies, N.A.Nicola A.; Hodson, M.E.Mark E.; Black, S.Stuart

    2003-01-01

    The current OECD acute worm toxicity test does not relate well to ambient conditions. - In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12500 μg Pb g -1 of soil. Calculated toxicities of the lead decreased in the order nitrate>carbonate>sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC 50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321±275 μg Pb g -1 of soil and this did not change with time. The LC 50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC 50 s for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10246 μg Pb g -1 of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance

  4. Role of environmental stress in the physiological response to chemical toxicants

    International Nuclear Information System (INIS)

    Gordon, C.J.

    2003-01-01

    Environmental physiology is the study of the physiological mechanisms that allow animals to cope with and adapt to changes in temperature, humidity, atmospheric pressure, and other natural factors of their physical environment. Nearly all toxicological and pharmacological studies are performed in resting (i.e., non exercising) experimental animals acclimatized to standard environmental conditions that are usually considered ideal to the animal's physiological well-being. These ideal test conditions are clearly not representative of the fluctuations in the natural environment encountered by humans and other animals on a day-to-day basis. It behooves the toxicologist, especially those interested in extrapolating experimental data from laboratory animals to humans, to consider how variations in the natural environment will alter physiological responses to toxicants. Temperature and exercise are the two most well-studied parameters in the fields of environmental physiology and toxicology. In general, high temperatures exacerbate the toxic effects of many environmental toxicants. Moreover, exercising subjects are generally more vulnerable to airborne toxic agents. The prospect of global warming also warrants a better assessment of how higher environmental temperatures may impact on the response of humans and other species to toxic chemicals. Hence, this paper and accompanying papers from the proceedings of a symposium focus on the salient aspects of the interaction between environmental stress and physiological response to toxic agents with particular emphasis on temperature and exercise

  5. Final Environmental Assessment for Rapid Attack Identification, Detection, and Reporting System - Block 10

    Science.gov (United States)

    2007-05-03

    Navassa Island, and Kingman Reef . 3 Through an agreement with the Republic of the Marshall Islands Government, US actions at USAKA are subject to...tripod (similar to the RE used at the Hosted Sites) 15 RAIDRS Block 10 Final Environmental Assessment Banana R ive r A t l an t i c...operations, wastewater treatment plants , fuel storage tanks, aircraft and ground vehicle refueling and maintenance operations, soil

  6. Molecular building blocks and their architecture in biologically/environmentally compatible soft matter chemical machinery.

    Science.gov (United States)

    Toyota, Taro; Banno, Taisuke; Nitta, Sachiko; Takinoue, Masahiro; Nomoto, Tomonori; Natsume, Yuno; Matsumura, Shuichi; Fujinami, Masanori

    2014-01-01

    This review briefly summarizes recent developments in the construction of biologically/environmentally compatible chemical machinery composed of soft matter. Since environmental and living systems are open systems, chemical machinery must continuously fulfill its functions not only through the influx and generation of molecules but also via the degradation and dissipation of molecules. If the degradation or dissipation of soft matter molecular building blocks and biomaterial molecules/polymers can be achieved, soft matter particles composed of them can be used to realize chemical machinery such as selfpropelled droplets, drug delivery carriers, tissue regeneration scaffolds, protocell models, cell-/tissuemarkers, and molecular computing systems.

  7. Triclosan: environmental exposure, toxicity and mechanisms of action.

    Science.gov (United States)

    Dann, Andrea B; Hontela, Alice

    2011-05-01

    Triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS] is a broad spectrum antibacterial agent used in personal care, veterinary, industrial and household products. TCS is commonly detected in aquatic ecosystems, as it is only partially removed during the wastewater treatment process. Sorption, biodegradation and photolytic degradation mitigate the availability of TCS to aquatic biota; however the by-products such as methyltriclosan and other chlorinated phenols may be more resistant to degradation and have higher toxicity than the parent compound. The continuous exposure of aquatic organisms to TCS, coupled with its bioaccumulation potential, have led to detectable levels of the antimicrobial in a number of aquatic species. TCS has been also detected in breast milk, urine and plasma, with levels of TCS in the blood correlating with consumer use patterns of the antimicrobial. Mammalian systemic toxicity studies indicate that TCS is neither acutely toxic, mutagenic, carcinogenic, nor a developmental toxicant. Recently, however, concern has been raised over TCS's potential for endocrine disruption, as the antimicrobial has been shown to disrupt thyroid hormone homeostasis and possibly the reproductive axis. Moreover, there is strong evidence that aquatic species such as algae, invertebrates and certain types of fish are much more sensitive to TCS than mammals. TCS is highly toxic to algae and exerts reproductive and developmental effects in some fish. The potential for endocrine disruption and antibiotic cross-resistance highlights the importance of the judicious use of TCS, whereby the use of TCS should be limited to applications where it has been shown to be effective. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Exploring Environmental Inequity in South Korea: An Analysis of the Distribution of Toxic Release Inventory (TRI Facilities and Toxic Releases

    Directory of Open Access Journals (Sweden)

    D. K. Yoon

    2017-10-01

    Full Text Available Recently, location data regarding the Toxic Release Inventory (TRI in South Korea was released to the public. This study investigated the spatial patterns of TRIs and releases of toxic substances in all 230 local governments in South Korea to determine whether spatial clusters relevant to the siting of noxious facilities occur. In addition, we employed spatial regression modeling to determine whether the number of TRI facilities and the volume of toxic releases in a given community were correlated with the community’s socioeconomic, racial, political, and land use characteristics. We found that the TRI facilities and their toxic releases were disproportionately distributed with clustered spatial patterning. Spatial regression modeling indicated that jurisdictions with smaller percentages of minorities, stronger political activity, less industrial land use, and more commercial land use had smaller numbers of toxic releases, as well as smaller numbers of TRI facilities. However, the economic status of the community did not affect the siting of hazardous facilities. These results indicate that the siting of TRI facilities in Korea is more affected by sociopolitical factors than by economic status. Racial issues are thus crucial for consideration in environmental justice as the population of Korea becomes more racially and ethnically diverse.

  9. Standardized toxicity testing may underestimate ecotoxicity: Environmentally relevant food rations increase the toxicity of silver nanoparticles to Daphnia.

    Science.gov (United States)

    Stevenson, Louise M; Krattenmaker, Katherine E; Johnson, Erica; Bowers, Alexandra J; Adeleye, Adeyemi S; McCauley, Edward; Nisbet, Roger M

    2017-11-01

    Daphnia in the natural environment experience fluctuations in algal food supply, with periods when algal populations bloom and seasons when Daphnia have very little algal food. Standardized chronic toxicity tests, used for ecological risk assessment, dictate that Daphnia must be fed up to 400 times more food than they would experience in the natural environment (outside of algal blooms) for a toxicity test to be valid. This disconnect can lead to underestimating the toxicity of a contaminant. We followed the growth, reproduction, and survival of Daphnia exposed to 75 and 200 µg/L silver nanoparticles (AgNPs) at 4 food rations for up to 99 d and found that AgNP exposure at low, environmentally relevant food rations increased the toxicity of AgNPs. Exposure to AgNP at low food rations decreased the survival and/or reproduction of individuals, with potential consequences for Daphnia populations (based on calculated specific population growth rates). We also found tentative evidence that a sublethal concentration of AgNPs (75 µg/L) caused Daphnia to alter energy allocation away from reproduction and toward survival and growth. The present findings emphasize the need to consider resource availability, and not just exposure, in the environment when estimating the effect of a toxicant. Environ Toxicol Chem 2017;36:3008-3018. © 2017 SETAC. © 2017 SETAC.

  10. Toxicogenetics: in search of host susceptibility to environmental toxicants

    OpenAIRE

    Alam, Gelareh; Jones, Byron C.

    2014-01-01

    Heavy metals, various pesticide and herbicides are implicated as risk factors for human health. Paraquat, maneb, and rotenone, carbamate, and organophosphorous insecticides are examples of toxicants for which acute and chronic exposure are associated with multiple neurological disorders including Parkinson’s disease. Nevertheless, the role of pesticide exposure in neurodegenerative diseases is not clear-cut, as there are inconsistencies in both the epidemiological and preclinical research. Th...

  11. TOXICOPHORES AND QUANTITATIVE STRUCTURE -TOXICITY RELATIONSHIPS FOR SOME ENVIRONMENTAL POLLUTANTS

    Directory of Open Access Journals (Sweden)

    N. N. Gorinchoy

    2008-06-01

    Full Text Available The electron-conformational (EC method is employed to reveal the toxicophore and to predict aquatic toxicity quantitatively using as a training set a series of 51 compounds that have aquatic toxicity to fish. By performing conformational analysis (optimization of geometries of the low-energy conformers by the PM3 method and electronic structure calculations (by ab initio method corrected within the SM54/PM3 solvatation model, the Electron-Conformational Matrix of Congruity (ECMC was constructed for each conformation of these compounds. The toxicophore defined as the EC sub-matrix of activity (ECSA, a sub-matrix with matrix elements common to all the active compounds under consideration within minimal tolerances, is determined by an iterative procedure of comparison of their ECMC’s, gradually minimizing the tolerances. Starting with only the four most toxic compounds, their ECSA (toxicophore was found to consists of a 4x4 matrix (four sites with certain electronic and topologic characteristics which was shown to be present in 17 most active compounds. A structure-toxicity correlation between three toxicophore parameters and the activities of these 17 compounds with R2=0.94 was found. It is shown that the same toxicophore with larger tolerances satisfies the compounds with les activity, thus explicitly demonstrating how the activity is controlled by the tolerances quantitatively and which atoms (sites are most flexible in this respect. This allows for getting slightly different toxicophores for different levels of activity. For some active compounds that have no toxicophore a bimolecular mechanism of activity is suggested. Distinguished from other QSAR methods, no arbitrary descriptors and no statistics are involved in this EC structure-activity investigation.

  12. Plants as Useful Vectors to Reduce Environmental Toxic Arsenic Content

    OpenAIRE

    Nosheen Mirza; Qaisar Mahmood; Mohammad Maroof Shah; Arshid Pervez; Sikander Sultan

    2014-01-01

    Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, applica...

  13. Environmentally safe management of radioactive and toxic sludges

    International Nuclear Information System (INIS)

    Shingarev, N.E.; Mukhin, I.V.; Polyakov, A.S.; Raginsky, L.S.; Semenov, B.A.

    2000-01-01

    Toxic industrial wastes constitute a significant part of Russian natural environment. The most reliable route to provide the long-term ecologic safety involves removal of toxicants or radioactive substances from polluted sites. With a view of processing toxic and radioactive sludges available in reservoirs, a process flowsheet is suggested that comprises the operations of sludge concentration, dehydration and granulation.Flocculation is an operation required to concentrate a solid phase. Polyacrylamide (PAA) and hydrolyzed PAA (HPAA) are standard flocculating agents used in the processing of sludges coming from storage facilities of radioactive wastes. HPAA is less efficient and it is shown that the optimized concentration of PAA is 4 mg/g solid. Flotation agents are used to extract the solid phase of sludges, it is shown that the process of extraction has to be carried out in 2 stages, the first flotation cycle with a Ph value between 7.5 and 9.5 and the second with a Ph adjustment to 3.5-6.0.The cake resulting from the sludge filtration has poor technological properties, it is advisable to produce a granular material. Hydro-granulation using hydrophobic flocculating agents may be implemented immediately after sludge concentration. The other granulation technique involves the sol-gel process used to incorporate sludge into a ceramic (aluminium oxide) matrix

  14. The pT-value as environmental policy indicator for the exposure to toxic substances

    NARCIS (Netherlands)

    Slooff W; de Zwart D

    1991-01-01

    This report contains a proposal for an indicator to measure the effectivity of the environmental policy with regard to the theme "Verspreiding" of the Directorate-General for Environmental Protection. It is recommended to use a method which indicates the toxicity of organic pollutants as

  15. Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates

    Science.gov (United States)

    Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn

    2016-01-01

    Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.

  16. Comparative developmental toxicity of environmentally relevant oxygenated PAHs

    International Nuclear Information System (INIS)

    Knecht, Andrea L.; Goodale, Britton C.; Truong, Lisa; Simonich, Michael T.; Swanson, Annika J.; Matzke, Melissa M.; Anderson, Kim A.; Waters, Katrina M.; Tanguay, Robert L.

    2013-01-01

    Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are byproducts of combustion and photo-oxidation of parent PAHs. OPAHs are widely present in the environment and pose an unknown hazard to human health. The developing zebrafish was used to evaluate a structurally diverse set of 38 OPAHs for malformation induction, gene expression changes and mitochondrial function. Zebrafish embryos were exposed from 6 to 120 h post fertilization (hpf) to a dilution series of 38 different OPAHs and evaluated for 22 developmental endpoints. AHR activation was determined via CYP1A immunohistochemistry. Phenanthrenequinone (9,10-PHEQ), 1,9-benz-10-anthrone (BEZO), xanthone (XAN), benz(a)anthracene-7,12-dione (7,12-B[a]AQ), and 9,10-anthraquinone (9,10-ANTQ) were evaluated for transcriptional responses at 48 hpf, prior to the onset of malformations. qRT-PCR was conducted for a number of oxidative stress genes, including the glutathione transferase(gst), glutathione peroxidase(gpx), and superoxide dismutase(sod) families. Bioenergetics was assayed to measure in vivo oxidative stress and mitochondrial function in 26 hpf embryos exposed to OPAHs. Hierarchical clustering of the structure-activity outcomes indicated that the most toxic of the OPAHs contained adjacent diones on 6-carbon moieties or terminal, para-diones on multi-ring structures. 5-carbon moieties with adjacent diones were among the least toxic OPAHs while the toxicity of multi-ring structures with more centralized para-diones varied considerably. 9,10-PHEQ, BEZO, 7,12-B[a]AQ, and XAN exposures increased expression of several oxidative stress related genes and decreased oxygen consumption rate (OCR), a measurement of mitochondrial respiration. Comprehensive in vivo characterization of 38 structurally diverse OPAHs indicated differential AHR dependency and a prominent role for oxidative stress in the toxicity mechanisms. - Highlights: • OPAHs are byproducts of combustion present in the environment. • OPAHs pose a largely

  17. Protective influence of healthful nutrition on mechanisms of environmental pollutant toxicity and disease risks.

    Science.gov (United States)

    Hoffman, Jessie B; Hennig, Bernhard

    2017-06-01

    Human exposures to environmental contaminants around the world contribute to the global burden of disease and thus require urgent attention. Exploring preventive measures against environmental exposure and disease risk is essential. While a sedentary lifestyle and/or poor dietary habits can exacerbate the deleterious effects resulting from exposure to toxic chemicals, much emerging evidence suggests that positive lifestyle changes (e.g., healthful nutrition) can modulate and/or reduce the toxicity of environmental pollutants. Our work has shown that diets high in anti-inflammatory bioactive food components (e.g., phytochemicals or polyphenols) are possible strategies for modulating and reducing the disease risks associated with exposure to toxic pollutants in the environment. Thus, consuming healthy diets rich in plant-derived bioactive nutrients may reduce the vulnerability to diseases linked to environmental toxic insults. This nutritional paradigm in environmental toxicology requires further study in order to improve our understanding of the relationships between nutrition and other lifestyle modifications and toxicant-induced diseases. © 2017 New York Academy of Sciences.

  18. Effect of the waste products storage on the environmental pollution by toxic organic compounds

    Directory of Open Access Journals (Sweden)

    Aleksandra Lewkiewicz-Małysa

    2005-11-01

    Full Text Available A permanent deposition of industrial wastes is a method of its neutralization. A storage yard for toxic materials must meet specific site and construction conditions. The storage place region of toxic organic waste materials has to be monitored. The environmental impact of this waste on the groundwater quality, especially the migration of persistent organic pollutants, was discussed on the example of a chemical plant.

  19. 17th Environmental Quality Index: Troubling Times with Toxics.

    Science.gov (United States)

    National Wildlife, 1986

    1986-01-01

    Presents a subjective analysis of the status of United States' natural resources, reviewing 1985's key environmental events, problems, and successes. Reports current conditions and/or dilemmas concerning wildlife, air, water, energy, forests, and soils. Provides both a public rating of the quality of life and a priority ranking of environmental…

  20. Plants as useful vectors to reduce environmental toxic arsenic content.

    Science.gov (United States)

    Mirza, Nosheen; Mahmood, Qaisar; Maroof Shah, Mohammad; Pervez, Arshid; Sultan, Sikander

    2014-01-01

    Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, application of municipal sludge on land, combustion of fossil fuels, As additives to livestock feed, coal fly ash, and use of arsenical pesticides in agricultural sector. Phytoremediation can be viewed as biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the natural ecosystems for subsequent productive use. The present review presents recent scientific developments regarding phytoremediation of arsenic contaminated environments and its possible detoxification mechanisms in plants.

  1. Plants as Useful Vectors to Reduce Environmental Toxic Arsenic Content

    Directory of Open Access Journals (Sweden)

    Nosheen Mirza

    2014-01-01

    Full Text Available Arsenic (As toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, application of municipal sludge on land, combustion of fossil fuels, As additives to livestock feed, coal fly ash, and use of arsenical pesticides in agricultural sector. Phytoremediation can be viewed as biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system that enhances the natural ecosystems for subsequent productive use. The present review presents recent scientific developments regarding phytoremediation of arsenic contaminated environments and its possible detoxification mechanisms in plants.

  2. Toxicogenetics: In Search of Host Susceptibility to Environmental Toxicants

    Directory of Open Access Journals (Sweden)

    Gelareh eAlam

    2014-09-01

    Full Text Available Heavy metals, various pesticide and herbicides are implicated as risk factors for human health. Paraquat, maneb, and rotenone, carbamate and organophospherous insecticides are examples of toxicants for which acute and chronic exposure are associated with multiple neurological disorders including Parkinson’s disease (PD. Nevertheless, the role of pesticide exposure in neurodegenerative diseases is not clear-cut, as there are inconsistencies in both the epidemiological and preclinical research. The aim of this short review is to show that the inconsistencies are related to individual differences in susceptibility to the effects of neurotoxicants, individual differences that can be traced to the genetic constitution of the individuals and animals studies, i.e., host-based susceptibility.

  3. Plants as Useful Vectors to Reduce Environmental Toxic Arsenic Content

    Science.gov (United States)

    Mirza, Nosheen; Mahmood, Qaisar; Maroof Shah, Mohammad; Pervez, Arshid; Sultan, Sikander

    2014-01-01

    Arsenic (As) toxicity in soil and water is an increasing menace around the globe. Its concentration both in soil and environment is due to natural and anthropogenic activities. Rising arsenic concentrations in groundwater is alarming due to the health risks to plants, animals, and human beings. Anthropogenic As contamination of soil may result from mining, milling, and smelting of copper, lead, zinc sulfide ores, hide tanning waste, dyes, chemical weapons, electroplating, gas exhaust, application of municipal sludge on land, combustion of fossil fuels, As additives to livestock feed, coal fly ash, and use of arsenical pesticides in agricultural sector. Phytoremediation can be viewed as biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the natural ecosystems for subsequent productive use. The present review presents recent scientific developments regarding phytoremediation of arsenic contaminated environments and its possible detoxification mechanisms in plants. PMID:24526924

  4. Effect Of Environmental Load On The Toxicity Of Bottom Sediments

    Directory of Open Access Journals (Sweden)

    Šestinová Oľga

    2015-06-01

    Full Text Available This study is devoted to Ecotoxicity tests, Terrestrial Plant Test (modification of OECD 208, Phytotoxkit microbiotest on Sinapis alba and chronic tests of Earthworm (Eisenia veneta, modification of OECD Guidelines for the testing of chemicals 317, Bioaccumulation in Terrestrial Oligochaetes on polluted sediments. Earthworms can accelerate the removal of contaminants from soil. The study materials are river sediments, which were obtained from a monitoring station - the Water reservoir the Ružín No.1 particularly, the river Hornád, Hnilec and sample from sludge bed Rudňany. The samples of sediment were used to assess of the potential phytotoxic effect of heavy metals on higher plants. Total mortality was established in earthworms using chronic toxicity test after 7 and 28 exposure days. Based on the phytotoxicity testing, phytotoxic effects of the metals contaminated sediments from the sludge bed Rudňany on S. alba seeds was observed. The largest concentration differences were recorded in the sample R7 after 7 days earthworms exposure. The earthworms mortality was not influenced by sediment neither after 7 nor 28 exposure days The spectra of samples H, HO and R showed broad peak at 1 419 - 1 512 cm−1 characteristic for carbonate radical. In the spectra of the samples (R and R7 the vibration of C-H groups at 2 926 and 2 921 cm−1, respectively were also observed, demonstrating the presence of organic matter. Our research will continue with determination of metals concentration in earthworms.

  5. Carbonated miscanthus mineralized aggregates for reducing environmental impact of lightweight concrete blocks

    Directory of Open Access Journals (Sweden)

    Courard Luc

    2017-01-01

    Full Text Available At a time when the cement industry is largely responsible for the production of CO2 in the construction sector, it is useful to make this production a reverse phenomenon: that is CO2 capture. The CO2 absorption process called carbonation, improves specific properties of the concrete during the conversion of carbon dioxide CO2 into calcium carbonate CaCO3. Current environmental concerns motivate the study of carbonation in order to maximize the absorption of carbon dioxide. Moreover, lightweight concrete with bio-based products knows an interesting development in the construction field, especially as thermal insulation panels for walls in buildings. Before identifying and quantifying the basic physical characteristics of concrete made from miscanthus, it is necessary to optimize the composition of the product. The long-term stability as well as the reinforcement may be obtained by means of a mineralization process of the natural product: a preparation with a lime and/or cement-based material is necessary to reinforce the cohesion of the bio-based product. Mineralization process is described as well as the way of producing blocks for CO2 capture by means of accelerated carbonation. Finally, concrete blocks produced with miscanthus mineralized aggregates offer interesting mechanical properties and minimal environmental impact.

  6. Environmental impact by toxic compounds from waste treatment; Miljoepaaverkan fraan toxiska aemnen vid hantering av avfall

    Energy Technology Data Exchange (ETDEWEB)

    Loefblad, Gun; Bisaillon, Mattias; Sundberg, Johan (Profu AB (Sweden))

    2010-07-01

    The study deals with emissions of toxic compounds from waste treatment to the environment with the aim of improving the state of knowledge and to find a way of describing the environmental impact from these substances. Toxicity is one of a number of environmental aspects necessary to address in the planning of waste treatment and in the daily waste treatment routines in order to fulfill the environmental objective A Non-Toxic Environment and other environmental requirements. The study includes waste to incineration, composting and anaerobic digestion. A comparison between methods were made for biological household waste. According to our study, the compounds of importance for waste treatment are metals and persistent organic compounds. These tend to bioaccumulate and enrich in food chains. The substances are important for the environmental objective A Non-Toxic Environment. In a first step the compounds chosen in this study may be suggested for describing toxicity from waste treatment: As, Cd, Cu, Hg, Pb, dioxin, PCB, the phthalate DEHP and the brominated flame retardant HBCDD. Other substances may be added to the list in a next step from up-dated and quality-assured characterisation factors or from other requirements or preferences. There is a limited knowledge on toxic compounds in waste flows and in different environmental compartments. More data are available for metals than for organic substances. There is also a limited knowledge on the fate of the compounds during the waste treatment processes. Most information is found for incineration. During composting and anaerobic digestion the metals will mainly be emitted to the environment by use of the compost and the anaerobic digestion residue. Organic substances will to some extent be degraded during the processes. However, there are gaps of knowledge to fill for the further work on estimating toxic emissions. There is mainly a need for more extensive data on toxic compounds in waste and their variations. A test

  7. U.S./Mexico Border environmental study toxics release inventory data, 1988--1992

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, R.F.; LoPresti, C.A.

    1996-02-01

    This is a report on industrial toxic chemical releases and transfers based on information reported to the Toxics Release Inventory (TRI), a database maintained by the USEPA. This document discusses patterns of toxic chemical releases to the atmosphere, to water, to the land, and to underground injection; and transfers of toxic chemicals to Publicly Owned Treatment Works (POTW), and for disposal, treatment and other off-site transfers during the TRI reporting years 1988--1992. Geographic coverage is limited to the US side of the ``Border Area``, the geographic area situated within 100 km of the US/Mexico international boundary. A primary purpose of this study is to provide background information that can be used in the future development of potential ``indicator variables`` for tracking environmental and public health status in the Border Area in conjunction with the implementation of the North American Free Trade Agreement (NAFTA).

  8. Interactions between toxic chemicals and natural environmental factors--a meta-analysis and case studies.

    Science.gov (United States)

    Laskowski, Ryszard; Bednarska, Agnieszka J; Kramarz, Paulina E; Loureiro, Susana; Scheil, Volker; Kudłek, Joanna; Holmstrup, Martin

    2010-08-15

    The paper addresses problems arising from effects of natural environmental factors on toxicity of pollutants to organisms. Most studies on interactions between toxicants and natural factors, including those completed in the EU project NoMiracle (Novel Methods for Integrated Risk Assessment of Cumulative Stressors in Europe) described herein, showed that effects of toxic chemicals on organisms can differ vastly depending purely on external conditions. We compiled data from 61 studies on effects of temperature, moisture and dissolved oxygen on toxicity of a range of chemicals representing pesticides, polycyclic aromatic hydrocarbons, plant protection products of bacterial origin and trace metals. In 62.3% cases significant interactions (pnatural factors and chemicals were found, reaching 100% for the effect of dissolved oxygen on toxicity of waterborne chemicals. The meta-analysis of the 61 studies showed that the null hypothesis assuming no interactions between toxic chemicals and natural environmental factors should be rejected at p=2.7 x 10(-82) (truncated product method probability). In a few cases of more complex experimental designs, also second-order interactions were found, indicating that natural factors can modify interactions among chemicals. Such data emphasize the necessity of including information on natural factors and their variation in time and across geographic regions in ecological risk assessment. This can be done only if appropriate ecotoxicological test designs are used, in which test organisms are exposed to toxicants at a range of environmental conditions. We advocate designing such tests for the second-tier ecological risk assessment procedures. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Chemopreventive agents attenuate rapid inhibition of gap junctional intercellular communication induced by environmental toxicants

    Czech Academy of Sciences Publication Activity Database

    Babica, Pavel; Čtveráčková, Lucie; Lenčešová, Zuzana; Trosko, J. E.; Upham, B. L.

    2016-01-01

    Roč. 68, č. 5 (2016), s. 827-837 ISSN 0163-5581 R&D Projects: GA MŠk LH12034 Institutional support: RVO:67985939 Keywords : gap junctional intercellular communication * chemopreventive agents * environmental toxicants Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.447, year: 2016

  10. Porous concrete block as an environmental enrichment device increases activity of laying hens in cages.

    Science.gov (United States)

    Holcman, A; Gorjanc, G; Stuhec, I

    2008-09-01

    The purpose of this study was to consider the influence of simple and cheap environmental enrichment such as porous concrete on the behavior of laying hens in conventional cages. Forty brown laying hens were housed in individual wire mesh cages: 20 in experimental cages with porous concrete block provided for pecking and 20 in a control group without concrete block provided. Porous concrete block (5 cm length x 5 cm width x 5 cm height) was mounted on the side wall at the height of the hen's head. Behavior was studied from 42 to 48 wk of age. A group of 8 hens was filmed for 24 h, and the camera was moved each day so that all 40 hens were recorded over 5 d each wk. Videotaping was performed in wk 1, 3, 5, and 7 of the experiment. States (long-term behavior) were observed with 5-min interval recording (feeding, preening, resting, and remaining inactive), whereas events (short-term activities) were observed with instantaneous recording (drinking, pecking concrete, pecking neighbors, pecking cage, and attempting to escape). Data were analyzed with generalized linear mixed model with binomial distribution for states, and Poisson distribution for events. Monte Carlo Markov Chain methods were used to estimate model parameters. Because posterior distributions of quantities of interest were skewed, medians and standard errors are reported. Hens in experimental cages were more active in long-term behavior than controls (64.9 +/- 1.9 and 59.3 +/- 1.9% of the light period, respectively). Correspondingly, hens in the control group showed more long-term inactivity. In addition to pecking the porous concrete block, hens in experimental cages also showed other short-term activities with greater frequency (4.10 +/- 0.31 and 3.51 +/- 0.25 events per h, respectively). Our hypothesis that hens in enriched cages would have a greater level of activity was confirmed. Provision of a piece of porous concrete block as a pecking substrate enriched the environment of the birds at negligible

  11. Potentially toxic concentrations in blood of total ropivacaine after bilateral transversus abdominis plane blocks; a pharmacokinetic study

    DEFF Research Database (Denmark)

    Torup, Henrik; Mitchell, Anja U; Breindahl, Torben

    2012-01-01

    Elevated blood levels of lidocaine and ropivacaine have been described after transversus abdominis plane (TAP) block.......Elevated blood levels of lidocaine and ropivacaine have been described after transversus abdominis plane (TAP) block....

  12. Environmental toxicants, incidence of degenerative diseases, and therapies from the epigenetic point of view.

    Science.gov (United States)

    Hodjat, Mahshid; Rahmani, Soheila; Khan, Fazlullah; Niaz, Kamal; Navaei-Nigjeh, Mona; Mohammadi Nejad, Solmaz; Abdollahi, Mohammad

    2017-07-01

    Epigenotoxicology is an emerging field of study that investigates the non-genotoxic epigenetic effects of environmental toxicants resulting in alteration of normal gene expression and disruption of cell function. Recent findings on the role of toxicant-induced epigenetic modifications in the development of degenerative diseases have opened up a promising research direction to explore epigenetic therapy approaches and related prognostic biomarkers. In this review, we presented comprehensive data on epigenetic alterations identified in various diseases, including cancer, autoimmune disorders, pulmonary conditions as well as cardiovascular, gastrointestinal and bone disease. Although data on abnormalities of DNA methylation and their role in the development of diseases are abundant, less is known about the impact of histone modifications and microRNA expressions. Further, we discussed the effects of selected common environmental toxicants on epigenetic modifications and their association with particular abnormalities. A number of different environmental toxicants have been identified for their role in aberrant DNA methylation, histone modifications, and microRNA expression. Such epigenetic effects were shown to be tissue-type specific and highly associated with the level and duration of exposure. Finally, we described present and future therapeutic strategies, including medicines and dietary compounds for combating the toxicant-induced epigenetic alterations. There are currently seven histone deacetylase inhibitors and two DNA methyltransferase inhibitors approved for clinical use and many other promising candidates are in preclinical and clinical testing. Dietary compounds are thought to be the effective and safe strategies for treating and prevention of epigenetic pathophysiological conditions. Still more concentrated epigenetic researches are required for evaluation of chemical toxicity and identifying the causal association between key epigenetic alteration and

  13. Modified whole effluent toxicity test to assess and decouple wastewater effects from environmental gradients.

    Directory of Open Access Journals (Sweden)

    Sebastián Sauco

    Full Text Available Environmental gradients and wastewater discharges produce aggregated effects on marine populations, obscuring the detection of human impact. Classical assessment methods do not include environmental effects in toxicity tests designs, which could lead to incorrect conclusions. We proposed a modified Whole Effluent Toxicity test (mWET that includes environmental gradients in addition to effluent dilutions, together with the application of Generalized Linear Mixed Models (GLMM to assess and decouple those effects. We tested this approach, analyzing the lethal effects of wastewater on a marine sandy beach bivalve affected by an artificial canal freshwater discharge used for rice crops irrigation. To this end, we compared bivalve mortality between canal water dilutions (CWd and salinity controls (SC: without canal water. CWd were prepared by diluting the water effluent (sampled during the pesticide application period with artificial marine water. The salinity gradient was included in the design by achieving the same final salinities in both CWd and SC, allowing us to account for the effects of salinity by including this variable as a random factor in the GLMM. Our approach detected significantly higher mortalities in CWd, indicating potential toxic effects of the effluent discharge. mWET represents an improvement over the internationally standardized WET tests, since it considers environmental variability and uses appropriate statistical analyses.

  14. Inorganic nanomaterials in the aquatic environment: behavior, toxicity, and interaction with environmental elements

    Directory of Open Access Journals (Sweden)

    Krzyżewska Iwona

    2016-03-01

    Full Text Available The aim of this paper is to present characteristics, toxicity and environmental behavior of nanoparticles (NPs (silver, copper, gold, zinc oxide, titanium dioxide, iron oxide that most frequently occur in consumer products. In addition, NPs are addressed as the new aquatic environmental pollutant of the 21st century. NPs are adsorbed onto particles in the aquatic systems (clay minerals, fulvic and humic acids, or they can adsorb environmental pollutants (heavy metal ions, organic compounds. Nanosilver (nAg is released from consumer products into the aquatic environment. It can threaten aquatic organisms with high toxicity. Interestingly, copper nanoparticles (Cu-NPs demonstrate higher toxicity to bacteria and aquatic microorganisms than those of nanosilver nAg. Their small size and reactivity can cause penetration into the tissues and interfere with the metabolic systems of living organisms and bacterial biogeochemical cycles. The behavior of NPs is not fully recognized. Nevertheless, it is known that NPs can agglomerate, bind with ions (chlorides, sulphates, phosphates or organic compounds. They can also be bound or immobilized by slurry. The NPs behavior depends on process conditions, i.e. pH, ionic strength, temperature and presence of other chemical compounds. It is unknown how NPs behave in the aquatic environment. Therefore, the research on this problem should be carried out under different process conditions. As for the toxicity, it is important to understand where the differences in the research results come from. As NPs have an impact on not only aquatic organisms but also human health and life, it is necessary to recognize their toxic doses and know standards/regulations that determine the permissible concentrations of NPs in the environment.

  15. Incorporating pharmacokinetic differences between children and adults in assessing children's risks to environmental toxicants

    International Nuclear Information System (INIS)

    Ginsberg, Gary; Hattis, Dale; Sonawane, Babasaheb

    2004-01-01

    Children's risks from environmental toxicant exposure can be affected by pharmacokinetic factors that affect the internal dose of parent chemical or active metabolite. There are numerous physiologic differences between neonates and adults that affect pharmacokinetics including size of lipid, and tissue compartments, organ blood flows, protein binding capacity, and immature function of renal and hepatic systems. These factors combine to decrease the clearance of many therapeutic drugs, which can also be expected to occur with environmental toxicants in neonates. The net effect may be greater or lesser internal dose of active toxicant depending upon how the agent is distributed, metabolized, and eliminated. Child/adult pharmacokinetic differences decrease with increasing postnatal age, but these factors should still be considered in any children's age group, birth through adolescence, for which there is toxicant exposure. Physiologically based pharmacokinetic (PBPK) models can simulate the absorption, distribution, metabolism, and excretion of xenobiotics in both children and adults, allowing for a direct comparison of internal dose and risk across age groups. This review provides special focus on the development of hepatic cytochrome P-450 enzymes (CYPs) in early life and how this information, along with many factors unique to children, can be applied to PBPK models for this receptor population. This review describes a case study involving the development of neonatal PBPK models for the CYP1A2 substrates caffeine and theophylline. These models were calibrated with pharmacokinetic data in neonates and used to help understand key metabolic differences between neonates and adults across these two drugs

  16. Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination.

    Science.gov (United States)

    Bai, Shahla Hosseini; Ogbourne, Steven M

    2016-10-01

    Glyphosate has been the most widely used herbicide during the past three decades. The US Environmental Protection Agency (EPA) classifies glyphosate as 'practically non-toxic and not an irritant' under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg kg(-1) body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment, and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high-rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment.

  17. Effects of nanoplastics and microplastics on toxicity, bioaccumulation, and environmental fate of phenanthrene in fresh water.

    Science.gov (United States)

    Ma, Yini; Huang, Anna; Cao, Siqi; Sun, Feifei; Wang, Lianhong; Guo, Hongyan; Ji, Rong

    2016-12-01

    Contamination of fine plastic particles (FPs), including micrometer to millimeter plastics (MPs) and nanometer plastics (NPs), in the environment has caught great concerns. FPs are strong adsorbents for hydrophobic toxic pollutants and may affect their fate and toxicity in the environment; however, such information is still rare. We studied joint toxicity of FPs with phenanthrene to Daphnia magna and effects of FPs on the environmental fate and bioaccumulation of 14 C-phenanthrene in fresh water. Within the five sizes particles we tested (from 50 nm to 10 μm), 50-nm NPs showed significant toxicity and physical damage to D. magna. The joint toxicity of 50-nm NPs and phenanthrene to D. magna showed an additive effect. During a 14-days incubation, the presence of NPs significantly enhanced bioaccumulation of phenanthrene-derived residues in daphnid body and inhibited the dissipation and transformation of phenanthrene in the medium, while 10-μm MPs did not show significant effects on the bioaccumulation, dissipation, and transformation of phenanthrene. The differences may be attributed to higher adsorption of phenanthrene on 50-nm NPs than 10-μm MPs. Our findings underlined the high potential ecological risks of FPs, and suggested that NPs should be given more concerns, in terms of their interaction with hydrophobic pollutants in the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. The association of environmental toxicants and autism spectrum disorders in children

    International Nuclear Information System (INIS)

    Ye, Bi Su; Leung, Anna Oi Wah; Wong, Ming Hung

    2017-01-01

    Autism spectrum disorders (ASDs) is a set of complex neurodevelopment disorders that is prevalent in children and is increasing at a steady rate in recent years. However, the etiology of autism is still poorly understood. Humans are at higher risk of chemical exposure than in the past as a result of the increasing usage of chemicals in various fields, including food preservation, agriculture, industrial production, etc. A number of environmental agents have been suggested as contributing factors to ASD pathogenesis, which includes heavy metals (Hg and Pb), persistent organic pollutants (DDT, PBDEs and PCBs) and emerging chemicals of concern (phthalates and BPA). These three main categories of toxicants could be the cause of ASD in children. Recent research into the causes of ASD that have been linked to environment factors are reviewed in this paper. There are evidence supporting the etiological link between exposure to environmental toxicants and the development of ASD. Children exposed to these toxicants in the environment exhibit signature traits of ASD and have been reported with high body burdens of these chemicals and/or their metabolites, which may provide an explanation for the observed relation, yet comprehensive evidence in humans is limited, highlighting the need for further research. - Highlights: • Heavy metal, persistent organic pollutant, BPA and phthalate cause ASD in children. • Review of causes of ASD that are linked to environmental factors. • Etiological link between environmental toxicants exposures and ASD development. - Heavy metals, POPs, and emerging chemicals of concern are suggested as contributing factors in the development of ASD on the neurodevelopment in children.

  19. Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Dedi Futra

    2014-12-01

    Full Text Available In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri encapsulated in alginate microspheres is described. Cu(II, Cd(II, Pb(II, Zn(II, Cr(VI, Co(II, Ni(II, Ag(I and Fe(II were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD range of 2.4–5.7% (n = 8. The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD for Cu(II (6.40 μg/L, Cd(II (1.56 μg/L, Pb(II (47 μg/L, Ag(I (18 μg/L than Zn(II (320 μg/L, Cr(VI (1,000 μg/L, Co(II (1700 μg/L, Ni(II (2800 μg/L, and Fe(III (3100 μg/L. Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

  20. Use of environmental health-risk analysis for managing toxic substances

    International Nuclear Information System (INIS)

    McKone, T.E.

    1985-03-01

    This paper presents a set of simple models used to assess health risks based on toxicity, environmental mobility and persistence. These models use a representative landscape in order to describe the steady-state distribution of arsenic, tritiated water, and TCDD as a result of continuous additions to soil. This information is used to assess potential exposures. Application of the screening model to three chemically different carcinogens reveals that the environmental health risk does not scale with direct measures of toxicity. As estimated here, the environmental health risk of TCDD relative to tritiated water and arsenic is roughly an order of magnitude less than its cancer potency relative to these compounds. The difference is attributable in large part to the immobility of TCDD relative to tritium and the lower persistence of TCDD compared to arsenic. The purpose is to present a simple procedure for using the relative behavior of toxic species under prototype conditions as a basis for risk management. 21 refs., 4 tabs

  1. In vitro and environmental toxicity of reduced graphene oxide as an additive in automotive lubricants.

    Science.gov (United States)

    Esquivel-Gaon, Margarita; Nguyen, Nhung H A; Sgroi, Mauro F; Pullini, Daniele; Gili, Flavia; Mangherini, Davide; Pruna, Alina Iuliana; Rosicka, Petra; Sevcu, Alena; Castagnola, Valentina

    2018-04-05

    Despite the ground-breaking potential of nanomaterials, their safe and sustainable incorporation into an array of industrial markets prompts a deep and clear understanding of their potential toxicity for both humans and the environment. Among the many materials with great potential, graphene has shown promise in a variety of applications; however, the impact of graphene based products on living systems remains poorly understood. In this paper, we illustrate that via exploiting the tribological properties of graphene nanosheets, we can successfully improve both the frictional behaviour and the anti-wear capacity of lubricant oil for mechanical transmission. By virtue of reducing friction and enhancing lubricant lifetimes, we can forecast a reduction in friction based energy loss, in addition to a decrease in the carbon footprint of vehicles. The aforementioned positive environmental impact is further strengthened considering the lack of acute toxicity found in our extensive in vitro investigation, in which both eukaryotic and prokaryotic cells were tested. Collectively, our body of work suggests that by the use of safe nanoadditives we could contribute to reducing the environmental impact of transportation and therein take a positive step towards a more sustainable automotive sector. The workflow proposed here for the evaluation of human and environmental toxicity will allow for the study of nanosized bare graphene material and can be broadly applied to the translation of graphene-based nanomaterials into the market.

  2. Understanding environmental health inequalities through comparative intracategorical analysis: racial/ethnic disparities in cancer risks from air toxics in El Paso County, Texas.

    Science.gov (United States)

    Collins, Timothy W; Grineski, Sara E; Chakraborty, Jayajit; McDonald, Yolanda J

    2011-01-01

    This paper contributes to the environmental justice literature by analyzing contextually relevant and racial/ethnic group-specific variables in relation to air toxics cancer risks in a US-Mexico border metropolis at the census block group-level. Results indicate that Hispanics' ethnic status interacts with class, gender and age status to amplify disproportionate risk. In contrast, results indicate that non-Hispanic whiteness attenuates cancer risk disparities associated with class, gender and age status. Findings suggest that a system of white-Anglo privilege shapes the way in which race/ethnicity articulates with other dimensions of inequality to create unequal cancer risks from air toxics. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Toxicity evaluation of methoxy poly(ethylene oxide)-block-poly(ε-caprolactone) polymeric micelles following multiple oral and intraperitoneal administration to rats.

    Science.gov (United States)

    Binkhathlan, Ziyad; Qamar, Wajhul; Ali, Raisuddin; Kfoury, Hala; Alghonaim, Mohammed

    2017-09-01

    Methoxy poly(ethylene oxide)- block -poly(ɛ-caprolactone) (PEO- b -PCL) copolymers are amphiphilic and biodegradable copolymers designed to deliver a variety of drugs and diagnostic agents. The aim of this study was to synthesize PEO- b -PCL block copolymers and assess the toxic effects of drug-free PEO- b -PCL micelles after multiple-dose administrations via oral or intraperitoneal (ip) administration in rats. Assembly of block copolymers was achieved by co-solvent evaporation method. To investigate the toxicity profile of PEO- b -PCL micelles, sixty animals were divided into two major groups: The first group received PEO- b -PCL micelles (100 mg/kg) by oral gavage daily for seven days, while the other group received the same dose of micelles by ip injections daily for seven days. Twenty-four hours following the last dose, half of the animals from each group were sacrificed and blood and organs (lung, liver, kidneys, heart and spleen) were collected. Remaining animals were observed for further 14 days and was sacrificed at the end of the third week, and blood and organs were collected. None of the polymeric micelles administered caused any significant effects on relative organ weight, animal body weight, leucocytes count, % lymphocytes, liver and kidney toxicity markers and organs histology. Although the dose of copolymers used in this study is much higher than those used for drug delivery, it did not cause any significant toxic effects in rats. Histological examination of all the organs confirmed the nontoxic nature of the micelles.

  4. Toxicity evaluation of methoxy poly(ethylene oxide-block-poly(ε-caprolactone polymeric micelles following multiple oral and intraperitoneal administration to rats

    Directory of Open Access Journals (Sweden)

    Ziyad Binkhathlan

    2017-09-01

    Full Text Available Methoxy poly(ethylene oxide-block-poly(ɛ-caprolactone (PEO-b-PCL copolymers are amphiphilic and biodegradable copolymers designed to deliver a variety of drugs and diagnostic agents. The aim of this study was to synthesize PEO-b-PCL block copolymers and assess the toxic effects of drug-free PEO-b-PCL micelles after multiple-dose administrations via oral or intraperitoneal (ip administration in rats. Assembly of block copolymers was achieved by co-solvent evaporation method. To investigate the toxicity profile of PEO-b-PCL micelles, sixty animals were divided into two major groups: The first group received PEO-b-PCL micelles (100 mg/kg by oral gavage daily for seven days, while the other group received the same dose of micelles by ip injections daily for seven days. Twenty-four hours following the last dose, half of the animals from each group were sacrificed and blood and organs (lung, liver, kidneys, heart and spleen were collected. Remaining animals were observed for further 14 days and was sacrificed at the end of the third week, and blood and organs were collected. None of the polymeric micelles administered caused any significant effects on relative organ weight, animal body weight, leucocytes count, % lymphocytes, liver and kidney toxicity markers and organs histology. Although the dose of copolymers used in this study is much higher than those used for drug delivery, it did not cause any significant toxic effects in rats. Histological examination of all the organs confirmed the nontoxic nature of the micelles.

  5. Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

    Directory of Open Access Journals (Sweden)

    Ghada Bassioni

    2010-10-01

    Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

  6. Effect of Some Environmental Factors on the Toxicity of Azadirachtin to the Egyptian Cotton Leafworm Spodoptera littoralis (Boisduval (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    El-Sayed H. Shaurub

    2014-12-01

    Full Text Available Although the bio-degradation of azadirachtin was well studied under storage or environmental conditions, its toxicity was not characterized so far under the impact of environmental conditions. Therefore, the present study aims to elucidate the toxicity of azadirachtin, at the level of LC50, to the fourth larval instars of Spodoptera littoralis (Boisduval under the stress of temperature, ultraviolet radiation (365 nm (UV-A and of artificial sunlight. The increase in post-treatment temperatures insignificantly affected azadirachtin toxicity. Likewise, insignificant change was also attained for the increase in the exposure periods of both UV and sunlight, except for exposure to sunlight without UV filter starting from 10 h, where the toxicity of azadirachtin was significantly declined. It can be concluded that azadirachtin toxicity will last efficiently against S. littoralis larvae under the stress of the environmental factors prevailing during the season of cotton cultivation in Egypt.

  7. Allium -test as a tool for toxicity testing of environmental radioactive-chemical mixtures

    International Nuclear Information System (INIS)

    Oudalova, A A; Pyatkova, S V; Geras’kin, S A; Dikareva, N S

    2017-01-01

    Bioassay-based approaches have been propagated to assess toxicity of unknown mixtures of environmental contaminants, but it was rarely applied in cases of chemicals with radionuclides combinations. Two Allium -test studies were performed to assess environmental impact from potential sources of combined radioactive-chemical pollution. Study sites were located at nuclear waste storage facilities in European and in Far-Eastern parts of Russia. As environmental media under impact, waters from monitor wells and nearby water bodies were tested. Concentrations of some chemicals and radionuclides in the samples collected enhanced the permitted limits. Cytogenetic and cytotoxic effects were used as biological endpoints, namely, frequency and spectrum of chromosome aberrations and mitotic abnormalities in anatelophase cells as well as mitotic activity in Allium root tips. Sample points were revealed where waters have an enhanced mutagenic potential. The findings obtained could be used to optimize monitoring system and advance decision making on management and rehabilitation of industrial sites. The Allium -test could be recommended and applied as an effective tool for toxicity testing in case of combined contamination of environmental compartments with radionuclides and chemical compounds. (paper)

  8. Allium-test as a tool for toxicity testing of environmental radioactive-chemical mixtures

    Science.gov (United States)

    Oudalova, A. A.; Geras'kin, S. A.; Dikareva, N. S.; Pyatkova, S. V.

    2017-01-01

    Bioassay-based approaches have been propagated to assess toxicity of unknown mixtures of environmental contaminants, but it was rarely applied in cases of chemicals with radionuclides combinations. Two Allium-test studies were performed to assess environmental impact from potential sources of combined radioactive-chemical pollution. Study sites were located at nuclear waste storage facilities in European and in Far-Eastern parts of Russia. As environmental media under impact, waters from monitor wells and nearby water bodies were tested. Concentrations of some chemicals and radionuclides in the samples collected enhanced the permitted limits. Cytogenetic and cytotoxic effects were used as biological endpoints, namely, frequency and spectrum of chromosome aberrations and mitotic abnormalities in anatelophase cells as well as mitotic activity in Allium root tips. Sample points were revealed where waters have an enhanced mutagenic potential. The findings obtained could be used to optimize monitoring system and advance decision making on management and rehabilitation of industrial sites. The Allium-test could be recommended and applied as an effective tool for toxicity testing in case of combined contamination of environmental compartments with radionuclides and chemical compounds.

  9. The functional range of heat shock proteins to combat environmental toxicity

    International Nuclear Information System (INIS)

    Mahmood, K.; Mahmood, Q.; Pervez, A.; Nasreen, S.

    2012-01-01

    Almost all the organisms possess a system to cope with the harsh physiochemical factors of environment. Such a system is based on a group of stress genes, which show rapid responses in form of stress proteins, especially heat shock proteins, when cells are confronted with insult. Heat shock proteins are now known to express in response to variety of toxic and stress conditions including diseases. As a molecular chaperone, against cytotoxicity, these ensure the functional ability of cells by repairing the denatured proteins, cellular structures like cytoskeleton and centrosomes and processes dealing with protein synthesis are stabilized or repaired during a second stress in stress tolerant cells and organisms. In unstressed cells these play an imperative role in the synthesis and transport of normal proteins. Their role in certain diseases reveals their potential application in medical field. Certain Hsp are helpful in coping carcinogenicity caused environmental pollutants and have been suggested to have anti-apoptotic, anti stress and anti-allergic function. Their expression is tissue and species specific with respect to type, intensity and duration of a toxicant. These are developmentally regulated and help in process of differentiation and thus their abnormal regulation impairs the normal development. However, their role as bio marker in risk assessment of environmental pollution warrants further research. Due to broad functional range, therefore, present review is embracing the functional aspects of smaller and Hsp 70 families expressing in animals under toxic conditions. (author)

  10. Environmental properties of long chain alcohols. Part 1: Physicochemical, environmental fate and acute aquatic toxicity properties

    DEFF Research Database (Denmark)

    Fisk, Peter; Sanderson, Hans; Wildey, Ross

    2009-01-01

    )SARs). This allows predictions of data relating to human and environmental safety profiles and patterns. These alcohols have been shown to be rapidly degradable under standard conditions up to C18. Furthermore, evidence suggests that longer chain lengths are also rapidly biodegradable. While log Kow values suggest...

  11. Notification: Background Investigation Services EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

    Science.gov (United States)

    Project #OPE-FY14-0017, March 7, 2014. The OIG plans to begin the preliminary research phase of an evaluation of the EPA's efforts to incorporate environmental justice into Clean Air Act (CAA) inspections for air toxics.

  12. Development of thresholds of excess toxicity for environmental species and their application to identification of modes of acute toxic action.

    Science.gov (United States)

    Li, Jin J; Zhang, Xu J; Yang, Yi; Huang, Tao; Li, Chao; Su, Limin; Zhao, Yuan H; Cronin, Mark T D

    2018-03-01

    The acute toxicity of organic pollutants to fish, Daphnia magna, Tetrahymena pyriformis, and Vibrio fischeri was investigated. The results indicated that the Toxicity Ratio (TR) threshold of log TR =1, which has been based on the distribution of toxicity data to fish, can also be used to discriminate reactive or specifically acting compounds from baseline narcotics for Daphnia magna and Vibrio fischeri. A log TR=0.84 is proposed for Tetrahymena pyriformis following investigation of the relationships between the species sensitivity and the absolute averaged residuals (AAR) between the predicted baseline toxicity and the experimental toxicity. Less inert compounds exhibit relatively higher toxicity to the lower species (Tetrahymena pyriformis and Vibrio fischeri) than the higher species (fish and Daphnia magna). A greater number of less inert compounds with log TR greater than the thresholds was observed for Tetrahymena pyriformis and Vibrio fischeri. This may be attributed to the hydrophilic compounds which may pass more easily through cell membranes than the skin or exoskeleton of organisms and have higher bioconcentration factors in the lower species, leading to higher toxicity. Most of classes of chemical associated with excess toxicity to one species also exhibited excess toxicity to other species, however, a few classes with excess toxicity to one species exhibiting narcotic toxicity to other species and thus may have different MOAs between species. Some ionizable compounds have log TR much lower than one because of the over-estimated log K OW . The factors that influence the toxicity ratio calculated from baseline level are discussed in this paper. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The importance of environmental factors and matrices in the adsorption, desorption, and toxicity of butyltins

    DEFF Research Database (Denmark)

    Fang, Liping; Xu, Cuihong; Li, Ji

    2017-01-01

    detrimental effects on humans and aquatic organisms. This work provides a critical review of recent studies on the adsorption, desorption, bioaccumulation, and toxicity of BTs that can notably influence the distribution of BTs in the environment. Influence of environmental factors (e.g., pH and salinity......Butyltins (BTs) are considered as a group of the most important organometallic compounds in industry and agriculture. Due to their widespread use, large amounts of BTs including tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) have entered into the environment, and subsequently causing......) and adsorbents in the matrices (e.g., minerals, organic carbons, and quartz) on the adsorption, desorption, and toxicity of BTs is particularly addressed....

  14. Environmental Pollution, Toxicity Profile and Treatment Approaches for Tannery Wastewater and Its Chemical Pollutants.

    Science.gov (United States)

    Saxena, Gaurav; Chandra, Ram; Bharagava, Ram Naresh

    Leather industries are key contributors in the economy of many developing countries, but unfortunately they are facing serious challenges from the public and governments due to the associated environmental pollution. There is a public outcry against the industry due to the discharge of potentially toxic wastewater having alkaline pH, dark brown colour, unpleasant odour, high biological and chemical oxygen demand, total dissolved solids and a mixture of organic and inorganic pollutants. Various environment protection agencies have prioritized several chemicals as hazardous and restricted their use in leather processing however; many of these chemicals are used and discharged in wastewater. Therefore, it is imperative to adequately treat/detoxify the tannery wastewater for environmental safety. This paper provides a detail review on the environmental pollution and toxicity profile of tannery wastewater and chemicals. Furthermore, the status and advances in the existing treatment approaches used for the treatment and/or detoxification of tannery wastewater at both laboratory and pilot/industrial scale have been reviewed. In addition, the emerging treatment approaches alone or in combination with biological treatment approaches have also been considered. Moreover, the limitations of existing and emerging treatment approaches have been summarized and potential areas for further investigations have been discussed. In addition, the clean technologies for waste minimization, control and management are also discussed. Finally, the international legislation scenario on discharge limits for tannery wastewater and chemicals has also been discussed country wise with discharge standards for pollution prevention due to tannery wastewater.

  15. Insecticide toxicity to oriental fruit fly Bactrocera dorsalis (Diptera: Tephritidae) is influenced by environmental factors.

    Science.gov (United States)

    Lin, Yuying; Jin, Tao; Zeng, Ling; Lu, Yongyue

    2013-02-01

    In this study, we investigated the effects of environmental factors (temperature, dose, dietary source, and feeding density) on the insecticide tolerance of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). The results indicated that the toxicities of trichlorphon and abamectin to B. dorsalis increased with an increase in temperature. At 15-35 degrees C, the toxicity of beta-cypermethrin decreased with an increase in temperature at low doses (0.82 and 1.86 mg/L), but was similar at a high dose (4.18 mg/L). These results demonstrated that the temperature coefficient of beta-cypermethrin was related to both temperature and dosage. The insecticide sensitivity of B. dorsalis reared on different dietary sources was significantly different. Trichlorphon sensitivity of B. dorsalis fed on banana was the highest with an LC50 of 1.61 mg/L, followed by on apple, carambola, semiartificial diet, pear, mango, guava, orange, and papaya. With an increasing feeding density, the sensitivity of B. dorsalis adults to trichlorphon increased, while the sensitivities of B. dorsalis adults to abamectin and beta-cypermethrin decreased. The differences between LC50 values of insects reared at densities of 10 and 13 eggs/g of semiartificial diet to trichlorphon, abamectin and beta-cypermethrin were not significant. This result suggested that representative toxicity could be obtained by using adults developed at a feeding density between 10-13 eggs/g of semiartificial diet. Adult body weight was positively correlated with the LC50 value of trichlorphon, but was negatively correlated with the toxicities of abamectin and beta-cypermethrin. These results suggested that the effects of adult body weight on the toxicity of insecticides were different among different chemicals.

  16. Environmental impact of toxic elements in red mud studied by fractionation and speciation procedures.

    Science.gov (United States)

    Milačič, Radmila; Zuliani, Tea; Ščančar, Janez

    2012-06-01

    Aluminum (Al) is mostly produced from bauxite ore, which contains up to 70% of Al(2)O(3) (alumina). Before alumina is refined to aluminum metal, it is purified by hot alkaline extraction. As a waste by-product red mud is formed. Due to its high alkalinity and large quantities, it represents a severe disposal problem. In Kidričevo (Slovenia), red mud was washed with water before disposal, and after drying, covered with soil. In Ajka (Hungary), the red mud slurry was collected directly in a containment structure, which burst caused a major accident in October 2010. In the present work the environmental impact of toxic elements in red mud from Kidričevo and Ajka were evaluated by applying a sequential extraction procedure and speciation analysis. The predominant red mud fraction was the insoluble residue; nevertheless, environmental concern was focused on the highly mobile water-soluble fraction of Al and Cr. Al in the water-soluble Ajka mud fraction was present exclusively in form of toxic [Al(OH)(4)](-), while Cr existed in its toxic hexavalent form. Comparative assessment to red mud from Kidričevo (Slovenia) with a lower alkalinity (pH 9) with that from Ajka demonstrated significantly lower Al solubility and the presence of only trace amounts of Cr(VI), confirming that disposal of neutralized mud is environmentally much more acceptable and carries a smaller risk of ecological accidents. Since during the Ajka accident huge amounts of biologically available Al and moderate Cr(VI) concentrations were released into the terrestrial and aquatic environments, monitoring of Al and Cr(VI) set free during remedial actions at the contaminated site is essential. Particular care should be taken to minimize the risk of release of soluble Al species and Cr(VI) into water supplies and surface waters. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Environmental properties of long chain alcohols. Part 1: Physicochemical, environmental fate and acute aquatic toxicity properties

    DEFF Research Database (Denmark)

    Fisk, Peter; Sanderson, Hans; Wildey, Ross

    2009-01-01

    )SARs). This allows predictions of data relating to human and environmental safety profiles and patterns. These alcohols have been shown to be rapidly degradable under standard conditions up to C18. Furthermore, evidence suggests that longer chain lengths are also rapidly biodegradable. While log Kow values suggest......This paper summarises the physicochemical, biodegradation and acute aquatic ecotoxicity properties of long chain aliphatic alcohols. Properties of pure compounds are shown to follow somewhat predictable trends, which are amenable to estimation by quantitative structure-activity relationships ((Q...

  18. Lead: Aspects of its ecology and environmental toxicity. [physiological effects of lead compound contamination of environment

    Science.gov (United States)

    Siegel, S. M.

    1973-01-01

    An analysis of lead toxicity in the Hawaiian environment was conducted. It was determined that lead enters the environment as an industrial contaminant resulting from the combustion of leaded gasoline. The amount of lead absorbed by the plants in various parts of the Hawaiian Islands is reported. The disposition of lead in the sediments of canals and yacht basins was investigated. The methods for conducting the surveys of lead content are described. Possible consequences of continued environmental pollution by burning leaded gasoline are discussed.

  19. Fate, behaviour and toxicity of engineered nanomaterials in the environmental systems

    CSIR Research Space (South Africa)

    Musee, N

    2012-04-01

    Full Text Available ? Environmental risks of ENMs to biological organisms in the environment MUST satisfy two conditions: Hazard & Exposure ? Hazard (toxic effect): due to nano/bio interface ?interactions of ENMs with: Biomolecules, cell membranes, the cellular interior...., Langmuir, 2011, Effect of surface coating A: Unmodified AgNPs B: Modified SDS AgNPs Steric effects due to EDL, increased zeta potential and enhanced AgNPs stability DLS size measurements B: Modified Tween 80 AgNPs A: Unmodified AgNPs A: 0 ?L...

  20. Management of toxic waste resulting from decommissioning and environmental remediation of nuclear facilities in Northwest Russia

    International Nuclear Information System (INIS)

    Vysotskij, V.L.; Nikitin, V.S.; Kulikov, K.N.; Ivanov, S.A.; Bogdanova, G.S.; Zakharov, A.A.

    2008-01-01

    Integrated information on toxic wastes formed during utilization and rehabilitation of shutdown naval nuclear object at Northwest Russia is performed. Dynamics of their accumulation to 2025 is estimated. Necessity of present waste management review and search of new methods with the view of decrease of environmental risks by means of systematic reprocessing or economic favorable destruction. Several strategies are treated. Advantages and imperfections of each of them are estimated by safety factors and economic costs, and the most acceptable strategy is selected. Functional model is found. Lists of projects, technical means are given, periods, costs for its realization are evaluated. Guidelines are provided [ru

  1. The Impact of Pollution Prevention on Toxic Environmental Releases from U.S. Manufacturing Facilities.

    Science.gov (United States)

    Ranson, Matthew; Cox, Brendan; Keenan, Cheryl; Teitelbaum, Daniel

    2015-11-03

    Between 1991 and 2012, the facilities that reported to the U.S. Environmental Protection Agency's Toxic Release Inventory (TRI) Program conducted 370,000 source reduction projects. We use this data set to conduct the first quasi-experimental retrospective evaluation of how implementing a source reduction (pollution prevention) project affects the quantity of toxic chemicals released to the environment by an average industrial facility. We use a differences-in-differences methodology, which measures how implementing a source reduction project affects a facility's releases of targeted chemicals, relative to releases of (a) other untargeted chemicals from the same facility, or (b) the same chemical from other facilities in the same industry. We find that the average source reduction project causes a 9-16% decrease in releases of targeted chemicals in the year of implementation. Source reduction techniques vary in effectiveness: for example, raw material modification causes a large decrease in releases, while inventory control has no detectable effect. Our analysis suggests that in aggregate, the source reduction projects carried out in the U.S. since 1991 have prevented between 5 and 14 billion pounds of toxic releases.

  2. Toxicity of pentachlorophenol to aquatic organisms under naturally varying and controlled environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hedtke, S.F.; West, C.W.; Allen, K.N.; Norberg-King, T.J.; Mount, D.I.

    1986-06-01

    The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 values ranging from 85 micrograms/L for the white sucker Catastomus commersoni during the summer to greater than 7770 micrograms/L for the isopod Asellus racovitzai during the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceran Ceriodaphnia reticulata and the snail Physa gyrina. The greatest variation in toxicity was due to species sensitivity. Within a given, season there was as much as a 40-fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14-fold. There were also substantial differences in acute-chronic relationships, with acute/chronic ratios ranging from greater than 37 for C. reticulata to 1 for Simocephalus vetulus. It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental effects of PCP.

  3. Environmentally toxicant exposures induced intragenerational transmission of liver abnormalities in mice

    Directory of Open Access Journals (Sweden)

    Mohamed A. Al-Griw

    2017-08-01

    Full Text Available Environmental toxicants such as chemicals, heavy metals, and pesticides have been shown to promote transgenerational inheritance of abnormal phenotypes and/or diseases to multiple subsequent generations following parental and/ or ancestral exposures. This study was designed to examine the potential transgenerational action of the environmental toxicant trichloroethane (TCE on transmission of liver abnormality, and to elucidate the molecular etiology of hepatocyte cell damage. A total of thirty two healthy immature female albino mice were randomly divided into three equal groups as follows: a sham group, which did not receive any treatment; a vehicle group, which received corn oil alone, and TCE treated group (3 weeks, 100 μg/kg i.p., every 4th day. The F0 and F1 generation control and TCE populations were sacrificed at the age of four months, and various abnormalities histpathologically investigated. Cell death and oxidative stress indices were also measured. The present study provides experimental evidence for the inheritance of environmentally induced liver abnormalities in mice. The results of this study show that exposure to the TCE promoted adult onset liver abnormalities in F0 female mice as well as unexposed F1 generation offspring. It is the first study to report a transgenerational liver abnormalities in the F1 generation mice through maternal line prior to gestation. This finding was based on careful evaluation of liver histopathological abnormalities, apoptosis of hepatocytes, and measurements of oxidative stress biomarkers (lipid peroxidation, protein carbonylation, and nitric oxide in control and TCE populations. There was an increase in liver histopathological abnormalities, cell death, and oxidative lipid damage in F0 and F1 hepatic tissues of TCE treated group. In conclusion, this study showed that the biological and health impacts of environmental toxicant TCE do not end in maternal adults, but are passed on to offspring

  4. A Review of Environmental Occurrence, Fate, Exposure, and Toxicity of Benzothiazoles.

    Science.gov (United States)

    Liao, Chunyang; Kim, Un-Jung; Kannan, Kurunthachalam

    2018-05-01

    Benzothiazole and its derivatives (BTs) are high production volume chemicals that have been used for several decades in a large number of industrial and consumer products, including vulcanization accelerators, corrosion inhibitors, fungicides, herbicides, algicides, and ultraviolet (UV) light stabilizers. Several benzothiazole derivatives are used commercially, and widespread use of these chemicals has led to ubiquitous occurrence in diverse environmental compartments. BTs have been reported to be dermal sensitizers, respiratory tract irritants, endocrine disruptors, carcinogens, and genotoxicants. This article reviews occurrence and fate of a select group of BTs in the environment, as well as human exposure and toxicity. BTs have frequently been found in various environmental matrices at concentrations ranging from sub-ng/L (surface water) to several tens of μg/g (indoor dust). The use of BTs in a number of consumer products, especially in rubber products, has resulted in widespread human exposure. BTs undergo chemical, biological, and photolytic degradation in the environment, creating several transformation products. Of these, 2-thiocyanomethylthio-benzothiazole (2-SCNMeS-BTH) has been shown to be the most toxic. Epidemiological studies have shown excess risks of cancers, including bladder cancer, lung cancer, and leukemia, among rubber factory workers, particularly those exposed to 2-mercapto-benzothiazole (2-SH-BTH). Human exposure to BTs continues to be a concern.

  5. Integrated approaches for determination of environmental and human risks of persistent toxic substances

    International Nuclear Information System (INIS)

    Blaha, L.; Cupr, P.; Dusek, L.; Hilscherova, K.; Holoubek, I.; Klanova, J.

    2008-01-01

    Substances that are persistent and bioaccumulative often posses toxic characteristics and cause adverse human health or environmental effects. Basic objective of the long-term research project INCHEMBIOL undertaken by the Centre RECETOX are the complex studies of interactions among chemical compounds present in environmental compartments and their biological effects and studies of the fate of mainly persistent chemical compounds in the environment, their effects on the environment and living organisms including human. Destiny in this concept consists of a summary of transport (from their input in the environment, transport within the environmental compartment, where they are discharged, transport among compartments and long-range transport in the environment) and transformation processes (abiotic and biotic transformations). It also includes study of distribution equilibriums, properties conditioning their environmental behaviour, study of the transformation processes and their products. This complex approach is a part of long-term research activities of the centre RECETOX. In the contribution methods used and results obtained in exploration of the causality among chemical (presence of chemical compounds in the environment) and biological (mechanisms of effects on the living organisms) are described.

  6. Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification.

    Science.gov (United States)

    Lim, Seong-Rin; Kang, Daniel; Ogunseitan, Oladele A; Schoenung, Julie M

    2011-01-01

    Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.

  7. Incorporation of gypsum waste in ceramic block production: Proposal for a minimal battery of tests to evaluate technical and environmental viability of this recycling process.

    Science.gov (United States)

    Godinho-Castro, Alcione P; Testolin, Renan C; Janke, Leandro; Corrêa, Albertina X R; Radetski, Claudemir M

    2012-01-01

    Civil engineering-related construction and demolition debris is an important source of waste disposed of in municipal solid waste landfills. After clay materials, gypsum waste is the second largest contributor to the residential construction waste stream. As demand for sustainable building practices grows, interest in recovering gypsum waste from construction and demolition debris is increasing, but there is a lack of standardized tests to evaluate the technical and environmental viability of this solid waste recycling process. By recycling gypsum waste, natural deposits of gypsum might be conserved and high amounts of the waste by-product could be reused in the civil construction industry. In this context, this paper investigates a physical property (i.e., resistance to axial compression), the chemical composition and the ecotoxicological potential of ceramic blocks constructed with different proportions of clay, cement and gypsum waste, and assesses the feasibility of using a minimal battery of tests to evaluate the viability of this recycling process. Consideration of the results for the resistance to axial compression tests together with production costs revealed that the best formulation was 35% of plastic clay, 35% of non-plastic clay, 10% of Portland cement and 20% of gypsum waste, which showed a mean resistance of 4.64MPa. Energy dispersive X-ray spectrometry showed calcium and sulfur to be the main elements, while quartz, gypsum, ettringite and nacrite were the main crystalline compounds found in this formulation. Ecotoxicity tests showed that leachate from this formulation is weakly toxic toward daphnids and bacteria (EC(20%)=69.0 and 75.0, respectively), while for algae and fish the leachate samples were not toxic at the EC(50%) level. Overall, these results show that the addition of 20% of gypsum waste to the ceramic blocks could provide a viable substitute for clay in the ceramics industry and the tests applied in this study proved to be a useful tool

  8. Single chain variable fragment antibodies block aggregation and toxicity induced by familial ALS-linked mutant forms of SOD1.

    Science.gov (United States)

    Ghadge, Ghanashyam D; Pavlovic, John D; Koduvayur, Sujatha P; Kay, Brian K; Roos, Raymond P

    2013-08-01

    Approximately 10% of amyotrophic lateral sclerosis (ALS) cases are familial (known as FALS) with an autosomal dominant inheritance pattern, and ~25% of FALS cases are caused by mutations in Cu/Zn superoxide dismutase (SOD1). There is convincing evidence that mutant SOD1 (mtSOD1) kills motor neurons (MNs) because of a gain-of-function toxicity, most likely related to aggregation of mtSOD1. A number of recent reports have suggested that antibodies can be used to treat mtSOD1-induced FALS. To follow up on the use of antibodies as potential therapeutics, we generated single chain fragments of variable region antibodies (scFvs) against SOD1, and then expressed them as 'intrabodies' within a motor neuron cell line. In the present study, we describe isolation of human scFvs that interfere with mtSOD1 in vitro aggregation and toxicity. These scFvs may have therapeutic potential in sporadic ALS, as well as FALS, given that sporadic ALS may also involve abnormalities in the SOD1 protein or activity. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Biotransformation and induction: implications for toxicity, bioaccumulation and monitoring of environmental xenobiotics in fish

    International Nuclear Information System (INIS)

    Kleinow, K.M.; Melancon, M.J.; Lech, J.J.

    1987-01-01

    Biotransformation of xenobiotics in fish occurs by many of the same reactions as in mammals. These reactions have been shown to affect the bioaccumulation, persistence, residue dynamics, and toxicity of select chemicals in fish. P-450-dependent monooxygenase activity of fish can be induced by polycyclic aromatic hydrocarbons, but phenobarbital-type agents induce poorly, if at all. Fish monooxygenase activity exhibits ideal temperature compensation and sex-related variation. Induction of monooxygenase activity by polycyclic aromatic hydrocarbons can result in qualitative as well as quantitative changes in the metabolic profile of a chemical. Induction can also alter toxicity. In addition, multiple P-450 isozymes have been described for several fish species. The biotransformation productions of certain chemicals have been related to specific P-450 isozymes, and the formation of these products can be influenced by induction. Exposure of fish to low levels of certain environmental contaminants has resulted in induction of specific monooxygenase activities and monitoring of such activities has been suggested as a means of identifying areas of pollutant exposure in the wild

  10. Analysis of explosion-induced releases of toxic materials at an environmental restoration project

    International Nuclear Information System (INIS)

    Bloom, S.G.; Moon, W.H. Jr.

    1993-01-01

    Prior to 1988, a variety of materials were buried on the US DOE Oak Ridge Reservation. Records of the disposal operations are incomplete and toxic materials may have been placed adjacent to potential explosives. One of the safety concerns in conducting an environmental restoration project at the burial sites, is the possibility of an explosion which could release toxic materials to the atmosphere. A safety analysis examined the consequences of such releases by first postulating an upper bound for the strength of an explosive. A correlation, developed by Steindler and Seefeldt of Argonne National Laboratory, was then used to estimate the amount and particle-size distribution of the material that could become airborne from the explosion. The estimated amount of airborne material was the source term in an atmospheric dispersion model which was used to calculate infinite-time, concentration-time integrals and 5-minute, time- weighted average concentrations at locations down-wind from the explosion. The dispersion model includes particle deposition as a function of particle-size distribution class. The concentration-time integrals and average concentrations were compared to published guidelines to assess the consequences of an accidental explosion

  11. Toxicity effects of an environmental realistic herbicide mixture on the seagrass Zostera noltei.

    Science.gov (United States)

    Diepens, Noël J; Buffan-Dubau, Evelyne; Budzinski, Hélène; Kallerhoff, Jean; Merlina, Georges; Silvestre, Jérome; Auby, Isabelle; Nathalie Tapie; Elger, Arnaud

    2017-03-01

    Worldwide seagrass declines have been observed due to multiple stressors. One of them is the mixture of pesticides used in intensive agriculture and boat antifouling paints in coastal areas. Effects of mixture toxicity are complex and poorly understood. However, consideration of mixture toxicity is more realistic and ecologically relevant for environmental risk assessment (ERA). The first aim of this study was to determine short-term effects of realistic herbicide mixture exposure on physiological endpoints of Zostera noltei. The second aim was to assess the environmental risks of this mixture, by comparing the results to previously published data. Z. noltei was exposed to a mixture of four herbicides: atrazine, diuron, irgarol and S-metolachlor, simulating the composition of typical cocktail of contaminants in the Arcachon bay (Atlantic coast, France). Three stress biomarkers were measured: enzymatic activity of glutathione reductase, effective quantum yield (EQY) and photosynthetic pigment composition after 6, 24 and 96 h. Short term exposure to realistic herbicide mixtures affected EQY, with almost 100% inhibition for the two highest concentrations, and photosynthetic pigments. Effect on pigment composition was detected after 6 h with a no observed effect concentration (NOEC) of 1 μg/L total mixture concentration. The lowest EQY effect concentration at 10% (EC 10 ) (2 μg/L) and pigment composition NOEC with an assessment factor of 10 were above the maximal field concentrations along the French Atlantic coast, suggesting that there are no potential short term adverse effects of this particular mixture on Z. noltei. However, chronic effects on photosynthesis may lead to reduced energy reserves, which could thus lead to effects at whole plant and population level. Understanding the consequences of chemical mixtures could help to improve ERA and enhance management strategies to prevent further declines of seagrass meadows worldwide. Copyright © 2016

  12. Evaluating the environmental impact of artificial sweeteners: a study of their distributions, photodegradation and toxicities.

    Science.gov (United States)

    Sang, Ziye; Jiang, Yanan; Tsoi, Yeuk-Ki; Leung, Kelvin Sze-Yin

    2014-04-01

    While having a long tradition as safe food additives, artificial sweeteners are a newly recognized class of environmental contaminants due to their extreme persistence and ubiquitous occurrence in various aquatic ecosystems. Resistant to wastewater treatment processes, they are continuously introduced into the water environments. To date however, their environmental behavior, fate as well as long term ecotoxicological contributions in our water resources still remain largely unknown. As a first step in the comprehensive study of artificial sweeteners, this work elucidates the geographical/seasonal/hydrological interactions of acesulfame, cyclamate, saccharin and sucralose in an open coast system at an estuarine/marine junction. Higher occurrence of acesulfame (seasonal average: 0.22 μg L(-1)) and sucralose (0.05 μg L(-1)) was found in summer while saccharin (0.11  μg L(-1)) and cyclamate (0.10 μg L(-1)) were predominantly detected in winter. Seasonal observations of the four sweeteners suggest strong connections with the variable chemical resistance among different sweeteners. Our photodegradation investigation further projected the potential impact of persistent acesulfame and sucralose compounds under prolonged exposure to intensive solar irradiation. Real-time observation by UPLC-ESI/MS of the degradation profile in both sweeteners illustrated that formation of new photo by-products under prolonged UV irradiation is highly viable. Interestingly, two groups of kinetically behaved photodegradates were identified for acesulfame, one of which was at least six times more persistent than the parent compound. For the first time, acute toxicity for the degradates of both sweeteners were arbitrarily measured, revealing photo-enhancement factors of 575 and 17.1 for acesulfame and sucralose, respectively. Direct comparison of photodegradation results suggests that the phototoxicity of acesulfame degradation products may impact aquatic ecosystems. In an attempt

  13. Solubilization of trace organics in block copolymer micelles for environmental separation using membrane extraction principles

    Energy Technology Data Exchange (ETDEWEB)

    Hatton, T.A.

    1992-12-01

    The solubilization of a range of polycyclic aromatic hydrocarbons in block copolymer micelles has been studied as a function of polymer composition, architecture, and temperature. Micelle formation is favored at high temperatures, leading to significant enhancements in solubilization capacity. At low temperatures, however, micelles do not form and the solubilization capacity of the block copolymer solution for the organics is low; this provides a convenient method for the regeneration of micellar solutions used as solvents'' in the treatment of contaminated feed streams using membrane extraction principles. It has also been shown (in collaboration with K.P. Johnston of University of Texas, Austin) that supercritical CO[sub 2] can be used effectively for micelle regeneration. Theoretical calculations of the structure of block copolymer micelles in the presence and absence of solutes using self-consistent mean-field lattice theories have successfully captured the trends observed with changing polymer composition and architecture, often quantitatively. The temperature and composition dependence of the micellar properties were determined by allowing the individual polymer segments to assume both polar and non-polar conformations.

  14. Structurally-diverse, PPARγ-activating environmental toxicants induce adipogenesis and suppress osteogenesis in bone marrow mesenchymal stromal cells

    International Nuclear Information System (INIS)

    Watt, James; Schlezinger, Jennifer J.

    2015-01-01

    Environmental obesogens are a newly recognized category of endocrine disrupting chemicals that have been implicated in contributing to the rising rates of obesity in the United States. While obesity is typically regarded as an increase in visceral fat, adipocyte accumulation in the bone has been linked to increased fracture risk, lower bone density, and osteoporosis. Exposure to environmental toxicants that activate peroxisome proliferator activated receptor γ (PPARγ), a critical regulator of the balance of differentiation between adipogenesis and osteogenesis, may contribute to the increasing prevalence of osteoporosis. However, induction of adipogenesis and suppression of osteogenesis are separable activities of PPARγ, and ligands may selectively alter these activities. It currently is unknown whether suppression of osteogenesis is a common toxic endpoint of environmental PPARγ ligands. Using a primary mouse bone marrow culture model, we tested the hypothesis that environmental toxicants acting as PPARγ agonists divert the differentiation pathway of bone marrow-derived multipotent mesenchymal stromal cells towards adipogenesis and away from osteogenesis. The toxicants tested included the organotins tributyltin and triphenyltin, a ubiquitous phthalate metabolite (mono-(2-ethylhexyl) phthalate, MEHP), and two brominated flame retardants (tetrabromobisphenol-a, TBBPA, and mono-(2-ethylhexyl) tetrabromophthalate, METBP). All of the compounds activated PPARγ1 and 2. All compounds increased adipogenesis (lipid accumulation, Fabp4 expression) and suppressed osteogenesis (alkaline phosphatase activity, Osx expression) in mouse primary bone marrow cultures, but with different potencies and efficacies. Despite structural dissimilarities, there was a strong negative correlation between efficacies to induce adipogenesis and suppress osteogenesis, with the organotins being distinct in their exceptional ability to suppress osteogenesis. As human exposure to a mixture of

  15. Environmental contaminants and microRNA regulation: Transcription factors as regulators of toxicant-altered microRNA expression

    Energy Technology Data Exchange (ETDEWEB)

    Sollome, James; Martin, Elizabeth [Department of Environmental Science & Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill (United States); Sethupathy, Praveen [Department of Genetics, School of Medicine, University of North Carolina, Chapel Hill, NC (United States); Fry, Rebecca C., E-mail: rfry@unc.edu [Department of Environmental Science & Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill (United States); Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, NC (United States)

    2016-12-01

    MicroRNAs (miRNAs) regulate gene expression by binding mRNA and inhibiting translation and/or inducing degradation of the associated transcripts. Expression levels of miRNAs have been shown to be altered in response to environmental toxicants, thus impacting cellular function and influencing disease risk. Transcription factors (TFs) are known to be altered in response to environmental toxicants and play a critical role in the regulation of miRNA expression. To date, environmentally-responsive TFs that are important for regulating miRNAs remain understudied. In a state-of-the-art analysis, we utilized an in silico bioinformatic approach to characterize potential transcriptional regulators of environmentally-responsive miRNAs. Using the miRStart database, genomic sequences of promoter regions for all available human miRNAs (n = 847) were identified and promoter regions were defined as − 1000/+500 base pairs from the transcription start site. Subsequently, the promoter region sequences of environmentally-responsive miRNAs (n = 128) were analyzed using enrichment analysis to determine overrepresented TF binding sites (TFBS). While most (56/73) TFs differed across environmental contaminants, a set of 17 TFs was enriched for promoter binding among miRNAs responsive to numerous environmental contaminants. Of these, one TF was common to miRNAs altered by the majority of environmental contaminants, namely SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 3 (SMARCA3). These identified TFs represent candidate common transcriptional regulators of miRNAs perturbed by environmental toxicants. - Highlights: • Transcription factors that regulate environmentally-modulated miRNA expression are understudied • Transcription factor binding sites (TFBS) located within DNA promoter regions of miRNAs were identified. • Specific transcription factors may serve as master regulators of environmentally-mediated microRNA expression.

  16. Environmental contaminants and microRNA regulation: Transcription factors as regulators of toxicant-altered microRNA expression

    International Nuclear Information System (INIS)

    Sollome, James; Martin, Elizabeth; Sethupathy, Praveen; Fry, Rebecca C.

    2016-01-01

    MicroRNAs (miRNAs) regulate gene expression by binding mRNA and inhibiting translation and/or inducing degradation of the associated transcripts. Expression levels of miRNAs have been shown to be altered in response to environmental toxicants, thus impacting cellular function and influencing disease risk. Transcription factors (TFs) are known to be altered in response to environmental toxicants and play a critical role in the regulation of miRNA expression. To date, environmentally-responsive TFs that are important for regulating miRNAs remain understudied. In a state-of-the-art analysis, we utilized an in silico bioinformatic approach to characterize potential transcriptional regulators of environmentally-responsive miRNAs. Using the miRStart database, genomic sequences of promoter regions for all available human miRNAs (n = 847) were identified and promoter regions were defined as − 1000/+500 base pairs from the transcription start site. Subsequently, the promoter region sequences of environmentally-responsive miRNAs (n = 128) were analyzed using enrichment analysis to determine overrepresented TF binding sites (TFBS). While most (56/73) TFs differed across environmental contaminants, a set of 17 TFs was enriched for promoter binding among miRNAs responsive to numerous environmental contaminants. Of these, one TF was common to miRNAs altered by the majority of environmental contaminants, namely SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 3 (SMARCA3). These identified TFs represent candidate common transcriptional regulators of miRNAs perturbed by environmental toxicants. - Highlights: • Transcription factors that regulate environmentally-modulated miRNA expression are understudied • Transcription factor binding sites (TFBS) located within DNA promoter regions of miRNAs were identified. • Specific transcription factors may serve as master regulators of environmentally-mediated microRNA expression

  17. Toxicity of inorganic contaminants, individually and in environmental mixtures, to three endangered fishes (Colorado squawfish, bonytail, and razorback sucker)

    Science.gov (United States)

    Buhl, Kevin J.; Hamilton, S.J.

    1996-01-01

    Two life stages of three federally-listed endangered fishes, Colorado squawfish (Ptychocheilus lucius), bonytail (Gila elegans), and razorback sucker (Xyrauchen texanus) were exposed to copper, selenate, selenite, and zinc individually, and to mixtures of nine inorganics in a reconstituted water that simulated the water quality of the middle Green River, Utah. The mixtures simulated environmental ratios of arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc in two tributaries, Ashley Creek and Stewart Lake outlet, of the middle Green River. The rank order of toxicity of the individual inorganics, from most to least toxic, was: copper > zinc > selenite > selenate. Colorado squawfish larvae were more sensitive to all four inorganics and the two mixtures than the juveniles, whereas there was no consistent response between the two life stages for the other two species. There was no consistent difference in sensitivity to the inorganics among the three endangered fishes. Both mixtures exhibited either additive or greater than additive toxicity to these fishes. The primary toxic components in the mixtures, based on toxic units, were copper and zinc. Acute toxicity values were compared to measured environmental concentrations in the two tributaries to derive margins of uncertainty. Margins of uncertainty were low for both mixtures (9–22 for the Stewart Lake outlet mixture, and 12–32 for the Ashley Creek mixture), indicating that mixtures of inorganics derived from irrigation activities may pose a hazard to endangered fishes in the Green River.

  18. Transient receptor potential ankyrin 1 antagonists block the noxious effects of toxic industrial isocyanates and tear gases.

    Science.gov (United States)

    Bessac, Bret F; Sivula, Michael; von Hehn, Christian A; Caceres, Ana I; Escalera, Jasmine; Jordt, Sven-Eric

    2009-04-01

    The release of methyl isocyanate in Bhopal, India, caused the worst industrial accident in history. Exposures to industrial isocyanates induce lacrimation, pain, airway irritation, and edema. Similar responses are elicited by chemicals used as tear gases. Despite frequent exposures, the biological targets of isocyanates and tear gases in vivo have not been identified, precluding the development of effective countermeasures. We use Ca(2+) imaging and electrophysiology to show that the noxious effects of isocyanates and those of all major tear gas agents are caused by activation of Ca(2+) influx and membrane currents in mustard oil-sensitive sensory neurons. These responses are mediated by transient receptor potential ankyrin 1 (TRPA1), an ion channel serving as a detector for reactive chemicals. In mice, genetic ablation or pharmacological inhibition of TRPA1 dramatically reduces isocyanate- and tear gas-induced nocifensive behavior after both ocular and cutaneous exposures. We conclude that isocyanates and tear gas agents target the same neuronal receptor, TRPA1. Treatment with TRPA1 antagonists may prevent and alleviate chemical irritation of the eyes, skin, and airways and reduce the adverse health effects of exposures to a wide range of toxic noxious chemicals.

  19. Environmental contextualisation of potential toxic elements and polycyclic aromatic hydrocarbons in biochar

    International Nuclear Information System (INIS)

    Freddo, Alessia; Cai Chao; Reid, Brian J.

    2012-01-01

    Nine dissimilar biochars, produced from varying feedstock at different pyrolysis temperatures, are appraised with respect to concentrations of potentially toxic elements, specifically, metals, metalloids and polycyclic aromatic hydrocarbons (PAHs). Concentrations of the metals and metalloids varied with the following ranges (mg kg −1 ): 0.02–0.94, Cd; 0.12–6.48, Cr; 0.04–13.2, Cu; 0.1–1.37, Ni; 0.06–3.87, Pb; 0.94–207, Zn and 0.03–0.27, As. Σ 16 PAH concentrations (16 Environmental Protection Agency (EPA) PAHs) range between 0.08 mg kg −1 to 8.7 mg kg −1 . Subsequent comparison with background soil concentrations, concentration applied to the regulation of composted materials (Publicly Available Specification (PAS 100)) and European Union (EU) regulations relating to the application of sewage sludge to agricultural land suggest low risk associated with the concentrations of PTEs observed in biochar. Collectively, results suggest that environmental impacts attributable to metals, metalloids and PAHs associated with biochar following its application to soil are likely to be minimal. - Highlights: ► Concentrations of PTEs varied with feedstock and temperature of production. ► Of the PTEs Zn (0.94–207 mg kg −1 ) was of most priority. ► PTE levels did not infringe guidance values for compost or sewage sludge. ► Biochar ( −1 ) is unlikely to make any real difference to PTE concentrations in soil. - Environmental impacts attributable to metals, metalloids and PAHs associated with biochar following its application to soil are likely to be minimal.

  20. Defences against ammonia toxicity in tropical air-breathing fishes exposed to high concentrations of environmental ammonia: a review.

    Science.gov (United States)

    Ip, Y K; Chew, S F; Wilson, J M; Randall, D J

    2004-10-01

    In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH(3) excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which results in a reversed NH(3) partial pressure gradient (DeltaP(NH3)), there is retention of endogenous ammonia and uptake of exogenous ammonia. In this review, several tropical air-breathing fishes (giant mudskipper, African catfish, oriental weatherloach, swamp eel, four-eyed sleeper, abehaze and slender African lungfish), which can tolerate high environmental ammonia exposure, are used as examples to demonstrate how eight different adaptations can be involved in defence against ammonia toxicity. Four of these adaptations deal with ammonia toxicity at branchial and/or epithelial surfaces: (1) active excretion of NH(4)(+); (2) lowering of environmental pH; (3) low NH(3) permeability of epithelial surfaces; and (4) volatilization of NH(3), while another four adaptations ameliorate ammonia toxicity at the cellular and subcellular levels: (5) high tolerance of ammonia at the cellular and subcellular levels; (6) reduction in ammonia production; (7) glutamine synthesis; and (8) urea synthesis. The responses of tropical air-breathing fishes to high environmental ammonia are determined apparently by behavioural adaptations and the nature of their natural environments.

  1. Molecular toxicity of cerium oxide nanoparticles to the freshwater alga Chlamydomonas reinhardtii is associated with supra-environmental exposure concentrations

    Science.gov (United States)

    Taylor, Nadine S.; Merrifield, Ruth; Williams, Tim D.; Chipman, J. Kevin; Lead, Jamie R.; Viant, Mark R.

    2016-01-01

    Abstract Ceria nanoparticles (NPs) are widely used as fuel catalysts and consequently are likely to enter the environment. Their potential impacts on. biota at environmentally relevant concentrations, including uptake and toxicity, remain to be elucidated and quantitative data on which to assess risk are sparse. Therefore, a definitive assessment of the molecular and phenotypic effects of ceria NPs was undertaken, using well-characterised mono-dispersed NPs as their toxicity is likely to be higher, enabling a conservative hazard assessment. Unbiased transcriptomics and metabolomics approaches were used to investigate the potential toxicity of tightly constrained 4–5 nm ceria NPs to the unicellular green alga, Chlamydomonas reinhardtii, a sentinel freshwater species. A wide range of exposure concentrations were investigated from predicted environmental levels, to support hazard assessment, to supra-environmental levels to provide insight into molecular toxicity pathways. Ceria NPs were internalised into intracellular vesicles within C. reinhardtii, yet caused no significant effect on algal growth at any exposure concentration. Molecular perturbations were only detected at supra-environmental ceria NP-concentrations, primarily down-regulation of photosynthesis and carbon fixation with associated effects on energy metabolism. For acute exposures to small mono-dispersed particles, it can be concluded there should be little concern regarding their dispersal into the environment for this trophic level. PMID:25740379

  2. Cadmium toxicity investigated at the physiological and biophysical levels under environmentally relevant conditions using the aquatic model plant Ceratophyllum demersum

    Czech Academy of Sciences Publication Activity Database

    Andresen, Elisa; Kappel, S.; Stärk, H.-J.; Riegger, U.; Borovec, Jakub; Mattusch, J.; Heinz, A.; Schmelzer, C.E.H.; Matoušková, Šárka; Dickinson, B.; Küpper, Hendrik

    2016-01-01

    Roč. 210, č. 4 (2016), s. 1244-1258 ISSN 0028-646X Institutional support: RVO:60077344 ; RVO:67985831 Keywords : Ceratophyllum demersum * Environmentally relevant * Light-harvesting complexes (LHCs) * Toxic metals Subject RIV: CE - Biochemistry; DD - Geochemistry (GLU-S) Impact factor: 7.330, year: 2016

  3. Palatability and efficacy of bromadiolone rodenticide block bait previously exposed to environmental conditions.

    Science.gov (United States)

    Nakagawa, Lia; de Masi, Eduardo; Narciso, Emerson; Neto, Hildebrando Montenegro; Papini, Solange

    2015-10-01

    In São Paulo city, rodent infestation is considered to be a serious public health problem and is the object of a municipal rodent control programme. One of the most important routine methods involves baiting in sewers, using bromadiolone block bait in a pulsed baiting strategy. It has been observed that, after each pulse, bait is not always consumed, and its appearance is altered, which has led to concerns about efficacy. We assessed whether exposure to sewer conditions influences the palatability and efficacy of rodenticide baits to Norway rats (Rattus norvegicus). Baits containing bromadiolone as active ingredient were placed in sewers, removed after 30 days and offered to rats in a two-choice food trial and a no-choice food trial. The appearance of the rodenticide baits changed after 30 days exposure to sewer conditions, but they continued to be palatable and effective against rats. The level of mortality was considered to be satisfactory, 75% in the two-choice food trial and 100% in the no-choice food trial. Results support the reuse of rodenticide block bait in rodent control. It seems to be justified to continue using/reuse baits even when their appearance has changed after 30 days exposure in sewer systems. © 2014 Society of Chemical Industry.

  4. Executive Order 12898 and Social, Economic, and Sociopolitical Factors Influencing Toxic Release Inventory Facility Location in EPA Region 6: A Multi-Scale Spatial Assessment of Environmental Justice

    Science.gov (United States)

    Moore, Andrea Lisa

    2013-01-01

    Toxic Release Inventory facilities are among the many environmental hazards shown to create environmental inequities in the United States. This project examined four factors associated with Toxic Release Inventory, specifically, manufacturing facility location at multiple spatial scales using spatial analysis techniques (i.e., O-ring statistic and…

  5. Isotopically modified silver nanoparticles to assess nanosilver bioavailability and toxicity at environmentally relevant exposures

    Science.gov (United States)

    Croteau, Marie-Noële; Dybowska, Agnieszka D.; Luoma, Samuel N.; Misra, Superb K.; Valsami-Jones, Eugenia

    2014-01-01

    A major challenge in understanding the environmental implications of nanotechnology lies in studying nanoparticle uptake in organisms at environmentally realistic exposure concentrations. Typically, high exposure concentrations are needed to trigger measurable effects and to detect accumulation above background. But application of tracer techniques can overcome these limitations. Here we synthesised, for the first time, citrate-coated Ag nanoparticles using Ag that was 99.7 % 109Ag. In addition to conducting reactivity and dissolution studies, we assessed the bioavailability and toxicity of these isotopically modified Ag nanoparticles (109Ag NPs) to a freshwater snail under conditions typical of nature. We showed that accumulation of 109Ag from 109Ag NPs is detectable in the tissues of Lymnaea stagnalis after 24-h exposure to aqueous concentrations as low as 6 ng L–1 as well as after 3 h of dietary exposure to concentrations as low as 0.07 μg g–1. Silver uptake from unlabelled Ag NPs would not have been detected under similar exposure conditions. Uptake rates of 109Ag from 109Ag NPs mixed with food or dispersed in water were largely linear over a wide range of concentrations. Particle dissolution was most important at low waterborne concentrations. We estimated that 70 % of the bioaccumulated 109Ag concentration in L. stagnalis at exposures –1 originated from the newly solubilised Ag. Above this concentration, we predicted that 80 % of the bioaccumulated 109Ag concentration originated from the 109Ag NPs. It was not clear if agglomeration had a major influence on uptake rates.

  6. Direct method for impact assessment of environmental pollutants and toxicants causing health hazards

    International Nuclear Information System (INIS)

    Fazal-ur-Rehman; Adil, A.; Abdullah, A.; Masood, S.R.; Agha, A.

    1997-01-01

    Industrial waste pollutants and toxicants are released in three forms i.e. gas, liquid, solid or their admixtures, causing atmospheric , hydro spheric and lithospheric pollutions. Gaseous wastes pollute the surrounding air before entering the waste-cycle and bio-cycle through vegetation/ forestation(i.e., plant kingdom). Liquid wastes enter the water-cycle directly and speedily whereas solid wastes enter the water-cycle indirectly and slowly. All these wastes, as it is well known later on enter plant and animal kingdoms which ultimately effect the human health and make different body parts sick/malignant. Therefore, the regular monitoring of elemental composition of these body parts becomes imperative. The above mentioned format of impact assessment has been followed during different joint studies (carried out in collaboration with university of the Punjab, INMOL and other Departments) which are based on the analytical data collected during the period of last five years. These samples include specimens of blood serum, cancer tissues, drinking and running water, industrial wastes and effluents etc. The comparison, of analysis of samples of unaffected (healthy) and malignant body parts, leads to the direct assessment of environmental pollutants and the inhabitants. (author)

  7. Environmental conditions enhance toxicant effects in larvae of the ground beetle Pterostichus oblongopunctatus (Coleoptera: Carabidae)

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, Agnieszka J., E-mail: a.bednarska@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Laskowski, Ryszard, E-mail: ryszard.laskowski@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland)

    2009-05-15

    The wide geographical distribution of ground beetles Pterostichus oblongopunctatus makes them very likely to be exposed to several environmental stressors at the same time. These could include both climatic stress and exposure to chemicals. Our previous studies demonstrated that the combined effect of nickel (Ni) and chlorpyrifos (CHP) was temperature (T)-dependent in adult P. oblongopunctatus. Frequently the different developmental stages of an organism are differently sensitive to single stressors, and for a number of reasons, such as differences in exposure routes, their interactions may also take different forms. Because of this, we studied the effects of the same factors on the beetle larvae. The results showed that all factors, as well as their interactions, influenced larvae survival. The synergistic effect of Ni and CPF was temperature-dependent and the effect of Ni x T interaction on the proportion of emerged imagines indicated stronger toxicity of Ni at 25 deg. C than at 10 deg. C. - Combined negative effects of nickel and chlorpyrifos on carabid beetles depend on ambient temperature.

  8. [Behavioral-cognitive disorders due to chronic exposure to industrial and environmental toxic substances].

    Science.gov (United States)

    Mangone, Carlos A; Genovese, Osvaldo; Abel, Carlos

    2006-01-01

    A review of neurotoxics is made, given the low tendency to investigate for chronic exposure to environmental and industrial potential central nervous system toxic substances (heavy metals, insecticides, organic solvents and carbon monoxide) in the history of a patient consulting for behavioral - cognitive complains, and considering the potential overturn of the disease if a correct diagnosis and early treatment is made. to determine the onset of the cognitive - behavioral features, presentation pattern, diagnosis and treatment of such neurotoxics (NT). systematized search in Cochrane and Medline reviews, Embase and Lilacs. chronic exposure to neurotoxics can produce personality changes (sleeping problems, excitation, depression, delusions and hallucinations) as well as cognitive problems (memory, learning, language and cognitive reaction problems). NT may cause changes in the neuron morphology and its sub cellular structures, affecting its normal biochemistry and physiology (proteins and neurotransmitters synthesis). The clinical history, diagnosis and treatment of each neurotoxic are discussed. The NT must be taken in consideration among the possible different etiologies when a patient with a bizarre behavioral cognitive syndrome is examined.

  9. Bioassay standardization for the detection of allelopathic compounds and environmental toxicants using lettuce

    Directory of Open Access Journals (Sweden)

    Mateus Salomão Simões

    2013-09-01

    Full Text Available The purpose of this study was to assess different experimental conditions to determine a protocol for bioassays based on seed germination and early seedling growth using lettuce (Lactuca sativa L. cv. Grand Rapids as indicator species. This protocol aims to provide support for the standardization of assays of various chemicals such as allelochemicals and environmental toxicants. The following tests were performed: time of germination, temperature, light, solution volume and Petri dish size. For each test (except for time of germination, the influence of the conditions investigated was determined by the endpoints germination percentage, germination speed index, root length, seedling fresh weight and total dry weight. The results showed that variations in the methods altered the results. It is recommended that bioassays using L. sativa L. cv. Grand Rapids be carried out for a minimum period of four days for assessments of both germination and initial growth and that the experimental conditions include a temperature of 20°C, 90-mm Petri dishes or larger, 0.1 mL cypsela solution, and continuous light or 12-hour photoperiod.

  10. Aspects of nitrogen dioxide toxicity in environmental urban concentrations in human nasal epithelium

    International Nuclear Information System (INIS)

    Koehler, C.; Ginzkey, C.; Friehs, G.; Hackenberg, S.; Froelich, K.; Scherzed, A.; Burghartz, M.; Kessler, M.; Kleinsasser, N.

    2010-01-01

    Cytotoxicity and genotoxicity of nitrogen dioxide (NO 2 ) as part of urban exhaust pollution are widely discussed as potential hazards to human health. This study focuses on toxic effects of NO 2 in realistic environmental concentrations with respect to the current limit values in a human target tissue of volatile xenobiotics, the epithelium of the upper aerodigestive tract. Nasal epithelial cells of 10 patients were cultured as an air-liquid interface and exposed to 0.01 ppm NO 2 , 0.1 ppm NO 2 , 1 ppm NO 2 , 10 ppm NO 2 and synthetic air for half an hour. After exposure, genotoxicity was evaluated by the alkaline single-cell microgel electophoresis (Comet) assay and by induction of micronuclei in the micronucleus test. Depression of proliferation and cytotoxic effects were determined using the micronucleus assay and trypan blue exclusion assay, respectively. The experiments revealed genotoxic effects by DNA fragmentation starting at 0.01 ppm NO 2 in the Comet assay, but no micronucleus inductions, no changes in proliferation, no signs of necrosis or apoptosis in the micronucleus assay, nor did the trypan blue exclusion assay show any changes in viability. The present data reveal a possible genotoxicity of NO 2 in urban concentrations in a screening test. However, permanent DNA damage as indicated by the induction of micronuclei was not observed. Further research should elucidate the effects of prolonged exposure.

  11. Electrochemical processes for the environmental remediation of toxic Cr(VI): A review

    International Nuclear Information System (INIS)

    Jin, Wei; Du, Hao; Zheng, Shili; Zhang, Yi

    2016-01-01

    Highlights: • Recent advances in electrochemical technologies for practical Cr(VI) treatment applications was reviewed. • The mechanism and performance of electrocoagulation, electrochemical reduction, electrodialysis, electro-electrodialysis and electrodeionization were discussed and compared. • The remained challenges and future perspectives were commented. - Abstract: Hexavalent chromium Cr(VI) is extremely toxic and classified as one of the 17 chemicals posing the greatest threat to humans. Large amounts of Cr(VI) compounds are directly or indirectly discharged into the environment, therefore considerable efforts have been made to control the Cr(VI) concentration below the recommended level. It has been demonstrated that electrochemical technique is one of the most efficient and environmental benign approach for the Cr(VI) removal. This review aims at recent advances in electrochemical technology for practical Cr(VI) treatment applications. By using the “clean reagent” of electron, Cr(VI) can be completely eliminated or separated via different electrochemical techniques such as electrocoagulation, electrochemical reduction, electrodialysis, electro-electrodialysis and electrodeionization. Besides, the mechanism and performance of different strategies are commented and compared. The treatment process is largely dependent on variables such as pH, electrode materials, cell configuration and techniques integration. Furthermore, the remained limitation and challenges for the electrochemical Cr(VI) remediation are also discussed.

  12. Environmental conditions enhance toxicant effects in larvae of the ground beetle Pterostichus oblongopunctatus (Coleoptera: Carabidae)

    International Nuclear Information System (INIS)

    Bednarska, Agnieszka J.; Laskowski, Ryszard

    2009-01-01

    The wide geographical distribution of ground beetles Pterostichus oblongopunctatus makes them very likely to be exposed to several environmental stressors at the same time. These could include both climatic stress and exposure to chemicals. Our previous studies demonstrated that the combined effect of nickel (Ni) and chlorpyrifos (CHP) was temperature (T)-dependent in adult P. oblongopunctatus. Frequently the different developmental stages of an organism are differently sensitive to single stressors, and for a number of reasons, such as differences in exposure routes, their interactions may also take different forms. Because of this, we studied the effects of the same factors on the beetle larvae. The results showed that all factors, as well as their interactions, influenced larvae survival. The synergistic effect of Ni and CPF was temperature-dependent and the effect of Ni x T interaction on the proportion of emerged imagines indicated stronger toxicity of Ni at 25 deg. C than at 10 deg. C. - Combined negative effects of nickel and chlorpyrifos on carabid beetles depend on ambient temperature.

  13. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    International Nuclear Information System (INIS)

    Kunita, Itsuki; Kuroda, Shigeru; Nakagaki, Toshiyuki; Ueda, Kei-Ichi; Akita, Dai

    2017-01-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective. (paper)

  14. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    Science.gov (United States)

    Kunita, Itsuki; Ueda, Kei-Ichi; Akita, Dai; Kuroda, Shigeru; Nakagaki, Toshiyuki

    2017-09-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective.

  15. Environmental levels, toxicity and human exposure to tributyltin (TBT)-contaminated marine environment. a review. b_antizar@hotmail.com.

    Science.gov (United States)

    Antizar-Ladislao, Blanca

    2008-02-01

    Tributyltin (TBT) is a toxic chemical used for various industrial purposes such as slime control in paper mills, disinfection of circulating industrial cooling waters, antifouling agents, and the preservation of wood. Due to its widespread use as an antifouling agent in boat paints, TBT is a common contaminant of marine and freshwater ecosystems exceeding acute and chronic toxicity levels. TBT is the most significant pesticide in marine and freshwaters in Europe and consequently its environmental level, fate, toxicity and human exposure are of current concern. Thus, the European Union has decided to specifically include TBT compounds in its list of priority compounds in water in order to control its fate in natural systems, due to their toxic, persistent, bioaccumulative and endocrine disruptive characteristics. Additionally, the International Maritime Organization has called for a global treaty that bans the application of TBT-based paints starting 1 of January 2003, and total prohibition by 1 of January 2008. This paper reviews the state of the science regarding TBT, with special attention paid to the environmental levels, toxicity, and human exposure. TBT compounds have been detected in a number of environmental samples. In humans, organotin compounds have been detected in blood and in the liver. As for other persistent organic pollutants, dietary intake is most probably the main route of exposure to TBT compounds for the general population. However, data concerning TBT levels in foodstuffs are scarce. It is concluded that investigations on experimental toxicity, dietary intake, potential human health effects and development of new sustainable technologies to remove TBT compounds are clearly necessary.

  16. Perceptions of environmental health risks among residents in the "Toxic Doughnut": opportunities for risk screening and community mobilization.

    Science.gov (United States)

    White, Brandi M; Hall, Eric S

    2015-12-10

    Surrounded by landfills, and toxic and hazardous facilities, Altgeld Gardens is located in a "toxic doughnut". With high rates of environmentally-related conditions, residents have called for a community-based environmental health assessment to improve overall health in their community. The purpose of this study was to investigate the attitudes and beliefs of environmental health risks of Altgeld's residents which would assist community organizing efforts and provide the groundwork for a community-based environmental health assessment. A questionnaire was designed and administered to 42 Altgeld residents who also participated in focus groups to assess their perceptions of environmental health risks. All participants were Altgeld residents for at least two years and were fairly representative of the broader community. Physical and social hazards were primarily identified as posing risks to participants' family and the broader community. Physical hazards included the dumping of hazardous waste and landfills; social hazards were crime and drugs. These findings have been useful in community organizing efforts and in program planning for local community-based organizations and public health agencies. The results have also been used to prioritize health and environmental risk issues impacting the community.

  17. Assessment of the toxicity of a substance under Canadian environmental protection act, a case study. Polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nadon, B.; Germain, A.; Coillie, R. van [Environment Canada, Montreal (Canada)

    1995-12-31

    The Canadian Environmental Protection Act (CEPA) proclaimed in 1988 requires the Canadian Ministers of the Environment and of National Health and Welfare to assess the toxicity of different substances. A Priority Substances List containing 44 substances was developed and their assessments had to determine if they were `toxic`, according to the CEPA definition. This definition states that `a substance is toxic if it is entering or may enter the environment in a quantity or concentration or under conditions (a) having or that may have an immediate or long-term harmful effect on the environment, (b) constituting or that may constitute a danger to the environment on which human life depends; or (c) constituting or that may constitute a danger in Canada to human life of health.` This presentation use the assessment of the polycyclic aromatic hydrocarbons (PAHs) as an example of this procedure. (author)

  18. Assessment of the toxicity of a substance under Canadian environmental protection act, a case study. Polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Nadon, B; Germain, A; Coillie, R van [Environment Canada, Montreal (Canada)

    1996-12-31

    The Canadian Environmental Protection Act (CEPA) proclaimed in 1988 requires the Canadian Ministers of the Environment and of National Health and Welfare to assess the toxicity of different substances. A Priority Substances List containing 44 substances was developed and their assessments had to determine if they were `toxic`, according to the CEPA definition. This definition states that `a substance is toxic if it is entering or may enter the environment in a quantity or concentration or under conditions (a) having or that may have an immediate or long-term harmful effect on the environment, (b) constituting or that may constitute a danger to the environment on which human life depends; or (c) constituting or that may constitute a danger in Canada to human life of health.` This presentation use the assessment of the polycyclic aromatic hydrocarbons (PAHs) as an example of this procedure. (author)

  19. Quantifying synergy: a systematic review of mixture toxicity studies within environmental toxicology.

    Directory of Open Access Journals (Sweden)

    Nina Cedergreen

    Full Text Available Cocktail effects and synergistic interactions of chemicals in mixtures are an area of great concern to both the public and regulatory authorities. The main concern is whether some chemicals can enhance the effect of other chemicals, so that they jointly exert a larger effect than predicted. This phenomenon is called synergy. Here we present a review of the scientific literature on three main groups of environmentally relevant chemical toxicants: pesticides, metal ions and antifouling compounds. The aim of the review is to determine 1 the frequency of synergy, 2 the extent of synergy, 3 whether any particular groups or classes of chemicals tend to induce synergy, and 4 which physiological mechanisms might be responsible for this synergy. Synergy is here defined as mixtures with minimum two-fold difference between observed and predicted effect concentrations using Concentration Addition (CA as a reference model and including both lethal and sub-lethal endpoints. The results showed that synergy occurred in 7%, 3% and 26% of the 194, 21 and 136 binary pesticide, metal and antifoulants mixtures included in the data compilation on frequency. The difference between observed and predicted effect concentrations was rarely more than 10-fold. For pesticides, synergistic mixtures included cholinesterase inhibitors or azole fungicides in 95% of 69 described cases. Both groups of pesticides are known to interfere with metabolic degradation of other xenobiotics. For the four synergistic metal and 47 synergistic antifoulant mixtures the pattern in terms of chemical groups inducing synergy was less clear. Hypotheses in terms of mechanisms governing these interactions are discussed. It was concluded that true synergistic interactions between chemicals are rare and often occur at high concentrations. Addressing the cumulative rather than synergistic effect of co-occurring chemicals, using standard models as CA, is therefore regarded as the most important step in

  20. Quantifying synergy: a systematic review of mixture toxicity studies within environmental toxicology.

    Science.gov (United States)

    Cedergreen, Nina

    2014-01-01

    Cocktail effects and synergistic interactions of chemicals in mixtures are an area of great concern to both the public and regulatory authorities. The main concern is whether some chemicals can enhance the effect of other chemicals, so that they jointly exert a larger effect than predicted. This phenomenon is called synergy. Here we present a review of the scientific literature on three main groups of environmentally relevant chemical toxicants: pesticides, metal ions and antifouling compounds. The aim of the review is to determine 1) the frequency of synergy, 2) the extent of synergy, 3) whether any particular groups or classes of chemicals tend to induce synergy, and 4) which physiological mechanisms might be responsible for this synergy. Synergy is here defined as mixtures with minimum two-fold difference between observed and predicted effect concentrations using Concentration Addition (CA) as a reference model and including both lethal and sub-lethal endpoints. The results showed that synergy occurred in 7%, 3% and 26% of the 194, 21 and 136 binary pesticide, metal and antifoulants mixtures included in the data compilation on frequency. The difference between observed and predicted effect concentrations was rarely more than 10-fold. For pesticides, synergistic mixtures included cholinesterase inhibitors or azole fungicides in 95% of 69 described cases. Both groups of pesticides are known to interfere with metabolic degradation of other xenobiotics. For the four synergistic metal and 47 synergistic antifoulant mixtures the pattern in terms of chemical groups inducing synergy was less clear. Hypotheses in terms of mechanisms governing these interactions are discussed. It was concluded that true synergistic interactions between chemicals are rare and often occur at high concentrations. Addressing the cumulative rather than synergistic effect of co-occurring chemicals, using standard models as CA, is therefore regarded as the most important step in the risk

  1. Determination of bismuth in environmental samples by ICP-MS and basic examination of cell toxicity for their compounds

    International Nuclear Information System (INIS)

    Kobayashi, Jun; Matsukawa, Takehisa; Chiba, Momoko; Yokoyama, Kazuhito; Terada, Hiroshi; Sugiyama, Hideo

    2011-01-01

    We examined both bismuth content levels in some environmental water samples (tapwater, bottled drinking water and slag obtained by sewage disposal) by inductively coupled plasma mass spectrometry (ICP-MS) and cultured cell toxicity of their compounds by the MTT assay. For ICP-MS, the conditions examined were addition of internal standard (IS), apparatus condition, and determination range, etc. When we examined an IS, the advantage was not clear that the ICP-MS response of the IS candidate elements was very variable. However, the sample induction rate into ICP-MS is more changeable at any time. Since the correction of analytical results was enabled by the addition of IS, Tl-203 was selected for IS, and was used in this study. The determination lower limit was 11 ppt by using 10 ppb Tl. Bi was detected in a few environmental water samples at 20.4 ppt - 6.8 ppb (0.07-6.83 μg/g original slags), but Bi concentrations of most samples were lower than the determination limit. On the other hand, concerning cell toxicity, the subgallate and free gallic acid affected the lives of cultured cells. Especially, the toxicity of free gallic acid was higher. It has been understood that the toxicity is weakly adjusted by chelating with Bi. (author)

  2. Preparation and characterization of nickel-spiked freshwater sediments for toxicity tests: toward more environmentally realistic nickel partitioning

    Science.gov (United States)

    Brumbaugh, William G.; Besser, John M.; Ingersoll, Christopher G.; May, Thomas W.; Ivey, Chris D.; Schlekat, Christian E.; Garman, Emily R.

    2013-01-01

    Two spiking methods were compared and nickel (Ni) partitioning was evaluated during a series of toxicity tests with 8 different freshwater sediments having a range of physicochemical characteristics. A 2-step spiking approach with immediate pH adjustment by addition of NaOH at a 2:1 molar ratio to the spiked Ni was effective in producing consistent pH and other chemical characteristics across a range of Ni spiking levels. When Ni was spiked into sediment having a high acid-volatile sulfide and organic matter content, a total equilibration period of at least 10 wk was needed to stabilize Ni partitioning. However, highest spiking levels evidently exceeded sediment binding capacities; therefore, a 7-d equilibration in toxicity test chambers and 8 volume-additions/d of aerobic overlying water were used to avoid unrealistic Ni partitioning during toxicity testing. The 7-d pretest equilibration allowed excess spiked Ni and other ions from pH adjustment to diffuse from sediment porewater and promoted development of an environmentally relevant, 0.5- to 1-cm oxic/suboxic sediment layer in the test chambers. Among the 8 different spiked sediments, the logarithm of sediment/porewater distribution coefficient values (log Kd) for Ni during the toxicity tests ranged from 3.5 to 4.5. These Kd values closely match the range of values reported for various field Ni-contaminated sediments, indicating that testing conditions with our spiked sediments were environmentally realistic.

  3. Effects of nanomolar cadmium concentrations on water plants - comparison of biochemical and biophysical mechanisms of toxicity under environmentally relevant conditions

    OpenAIRE

    Andresen, Elisa

    2014-01-01

    In this thesis, the effects of the highly toxic heavy metal cadmium (Cd) on the rootless aquatic model plant Ceratophyllum demersum are investigated on the biochemical and biophysical level. The experiments were carried out using environmentally relevant conditions, i.e. light and temperature followed a sinusoidal cycle, a low biomass to water ratio resembled the situation in oligotrophic lakes and a continuous exchange of the defined nutrient solution ensured that metal uptake into the plant...

  4. Parametric Analysis of the Exergoeconomic Operation Costs, Environmental and Human Toxicity Indexes of the MF501F3 Gas Turbine

    Directory of Open Access Journals (Sweden)

    Edgar Vicente Torres-González

    2016-08-01

    Full Text Available This work presents an energetic, exergoeconomic, environmental, and toxicity analysis of the simple gas turbine M501F3 based on a parametric analysis of energetic (thermal efficiency, fuel and air flow rates, and specific work output, exergoeconomic (exergetic efficiency and exergoeconomic operation costs, environmental (global warming, smog formation, acid rain indexes, and human toxicity indexes, by taking the compressor pressure ratio and the turbine inlet temperature as the operating parameters. The aim of this paper is to provide an integral, systematic, and powerful diagnostic tool to establish possible operation and maintenance actions to improve the gas turbine’s exergoeconomic, environmental, and human toxicity indexes. Despite the continuous changes in the price of natural gas, the compressor, combustion chamber, and turbine always contribute 18.96%, 53.02%, and 28%, respectively, to the gas turbine’s exergoeconomic operation costs. The application of this methodology can be extended to other simple gas turbines using the pressure drops and isentropic efficiencies, among others, as the degradation parameters, as well as to other energetic systems, without loss of generality.

  5. Distributed Structure Searchable Toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Distributed Structure Searchable Toxicity (DSSTox) online resource provides high quality chemical structures and annotations in association with toxicity data....

  6. Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Qi [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Huang, Shan, E-mail: huangs@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Su, Wei [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan [College of Pharmacy, Guangxi Traditional Chinese Medical University, Nanning 530001 (China); Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Liu, Yi, E-mail: prof.liuyi@263.net [State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer The toxic effects of QDs to T. thermophila BF{sub 5} using a TAM air microcalorimeter. Black-Right-Pointing-Pointer QDs were acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner. Black-Right-Pointing-Pointer The toxicity of different ligands-capped QDs on T. thermophila BF{sub 5} was investigated. Black-Right-Pointing-Pointer QDs could be ingested by cells and affect the morphology of T. thermophila BF{sub 5}. - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF{sub 5} (T. thermophila BF{sub 5}) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd{sup 2+}, which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF{sub 5} was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5 Prime -monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF{sub 5} growth incubated with these QDs were further studied by fluorescence inverted microscopy.

  7. Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

    International Nuclear Information System (INIS)

    Xiao, Qi; Huang, Shan; Su, Wei; Li, Peiyuan; Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang; Liu, Yi

    2012-01-01

    Highlights: ► The toxic effects of QDs to T. thermophila BF 5 using a TAM air microcalorimeter. ► QDs were acutely toxic for T. thermophila BF 5 growth in a dose-dependent manner. ► The toxicity of different ligands-capped QDs on T. thermophila BF 5 was investigated. ► QDs could be ingested by cells and affect the morphology of T. thermophila BF 5 . - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF 5 (T. thermophila BF 5 ) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF 5 growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd 2+ , which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF 5 was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5′-monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF 5 growth incubated with these QDs were further studied by fluorescence inverted microscopy.

  8. Environmental labeling of car tires--toxicity to Daphnia magna can be used as a screening method.

    Science.gov (United States)

    Wik, Anna; Dave, Göran

    2005-02-01

    Car tires contain several water-soluble compounds that can leach into water and have toxic effects on aquatic organisms. Due to tire wear, 10,000 tonnes of rubber particles end up along the Swedish roads every year. This leads to a diffuse input of emissions of several compounds. Emissions of polyaromatic hydrocarbons (PAHs) are of particular concern. PAHs are ingredients of the high aromatic oil (HA oil) that is used in the rubber as a softener and as a filler. The exclusion of HA oils from car tires has started, and an environmental labeling of tires could make HA oils obsolete. The toxicity to Daphnia magna from 12 randomly selected car tires was tested in this study. Rubber from the tread of the tires was grated into small pieces, to simulate material from tire wear, and the rubber was equilibrated with dilution water for 72 h before addition of test organisms. The 24-h EC50s of the rubber pieces ranged from 0.29 to 32 gl-1, and the 48-h EC50s ranged from 0.0625 to 2.41 gl-1. Summer tires were more toxic than winter tires. After the 48-h exposure, the daphnids were exposed to UV-light for 2 h, to determine if the tires contained compounds that were phototoxic. After UV-activation the EC50s ranged from 0.0625 to 0.38 gl-1. Four of the 12 tires had a very distinct photoactivation, with a toxicity increase of >10 times. This study has shown that the used method for toxicity testing with Daphnia magna according to ISO 6341 could be used as a basis for environmental labeling of car tires.

  9. Environmental health: an analysis of available and proposed remedies for victims of toxic waste contamination

    International Nuclear Information System (INIS)

    Hurwitz, W.J.

    1981-01-01

    Past and present residents of the Love Canal area near Niagara Falls, New York, fear that they and their homes have been contaminated by toxic wastes seeping out from nearby chemical disposal sites. Hundreds of landfills nationwide are as potentially dangerous as Love Canal. In the absence of a statutory remedy, victims of contamination must rely upon common law theories of lability in order to recover damages for injuries suffered as a result of toxic waste contamination. This Note examines the merits and deficiencies of four common law theories: negligence, strict liability, nuisance and trespass. The Note concludes that none of these remedies is adequate to assure recovery to a person injured by toxic waste disposal, and recommends that legislation be adopted to ensure that victims of toxic waste contamination can be compensated for their injuries

  10. Environmental Toxicity of the Explosives RDX and TNT in Soil to the Soil Invertebrate Folsomia candida

    National Research Council Canada - National Science Library

    Phillips, Carlton T; Checkai, Ronald T; Kuperman, Roman G; Simini, Michael; Kolakowski, Jan E; Kurnas, Carl W

    2004-01-01

    ...; medium for RCL and KCL; and relatively low or WCL soil. We investigated whether soil type affects the toxicity of RDX or TNT in soil to Collembola by adapting a standardized Folsomia reproduction test (ISO 11267:1998...

  11. Toxicity of Carbon Nanotubes and its Implications for Occupational and Environmental Health

    Science.gov (United States)

    Lam, Chiu-wing; James, John T.

    2007-01-01

    This viewgraph document reviews the sources of Nano particles in the environment, the structure and properties of Carbon Nanotubes (CNTs), the physical characteristics of CNT materials, pulmonary and other health concerns of exposure to CNTs. The toxicity of CNT in rodents is summarized and some natural, and man-made sources of CNTs are shown. CNTs are electrically and thermally conductive, fibrous, biopersistent and very complicated in structures. The factors affecting toxicity of CNTs are more than size and surface area.

  12. Toxicity and environmental and economic performance of fly ash and recycled concrete aggregates use in concrete: A review

    Directory of Open Access Journals (Sweden)

    Rawaz Kurda

    2018-04-01

    Full Text Available This paper presents an overview of previous studies on the environmental impact (EI and toxicity of producing recycled concrete aggregates (RCA, fly ash (FA, cement, superplasticizer, and water as raw materials, and also on the effect of replacing cement and natural aggregates (NA with FA and RCA, respectively, on the mentioned aspects. EI and toxicity were analysed simultaneously because considering concrete with alternative materials as sustainable depends on whether their risk assessment is high. Therefore, this study mainly focuses on the cradle-to-gate EI of one cubic meter of concrete, namely abiotic depletion potential (ADP, global warming potential (GWP, ozone depletion potential (ODP, photochemical ozone creation (POCP, acidification potential (AP, eutrophication potential (EP, non-renewable energy (PE-NRe and renewable energy (PE-Re. In terms of toxicity, leachability (chemical and ecotoxicological characterization was considered. The results also include the economic performance of these materials, and show that the incorporation of FA in concrete significantly decreases the EI and cost of concrete. Thus, the simultaneous incorporation of FA and RCA decrease the EI, cost, use of landfill space and natural resources extraction. Nonetheless, the leaching metals of FA decrease when they are incorporated in concrete. Relative to FA, the incorporation of RCA does not significantly affect the EI and cost of concrete, but it significantly reduces the use of landfill space and the need of virgin materials. Keywords: Materials science, Environmental science, Industry, Economics, Safety engineering

  13. Nerve Blocks

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Nerve Blocks A nerve block is an injection to ... the limitations of Nerve Block? What is a Nerve Block? A nerve block is an anesthetic and/ ...

  14. Human toxicity as a criterion in the environmental assessment of products

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Olsen, Stig Irving; Wenzel, Henrik

    1998-01-01

    . The assessment proceeds through the steps of classification, characterization, normalization and valuation. In the classification step attention is focused on intrinsic toxicity, low biodegradability and potential for bioconcentration as properties that predicpose a substance for ecotoxicity. No concrete values...... references derived for each of these scenarios are presented as personal equivalents for citizens in the considered region. Valuation Applying the "distance to target principle to the present Danish political reduction targets for toxicity a weighting factor is derived to be used in the quantitative weighing...

  15. Exposure to Environmental Toxicants and Pathogenesis of Amyotrophic Lateral Sclerosis: State of the Art and Research Perspectives

    Directory of Open Access Journals (Sweden)

    Maria Rosaria Monsurrò

    2013-07-01

    Full Text Available There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS, a fatal neuromuscular disease, is caused by gene-environment interactions. In fact, given that only about 10% of all ALS diagnosis has a genetic basis, gene-environmental interaction may give account for the remaining percentage of cases. However, relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron degeneration leading to ALS, although exposure to chemicals—including lead and pesticides—agricultural environments, smoking, intense physical activity, trauma and electromagnetic fields have been associated with an increased risk of ALS. This review provides an overview of our current knowledge of potential toxic etiologies of ALS with emphasis on the role of cyanobacteria, heavy metals and pesticides as potential risk factors for developing ALS. We will summarize the most recent evidence from epidemiological studies and experimental findings from animal and cellular models, revealing that potential causal links between environmental toxicants and ALS pathogenesis have not been fully ascertained, thus justifying the need for further research.

  16. Cadmium toxicity investigated at the physiological and biophysical levels under environmentally relevant conditions using the aquatic model plant Ceratophyllum demersum

    DEFF Research Database (Denmark)

    Andresen, Elisa; Kappel, Sophie; Stärk, Hans-Joachim

    2016-01-01

    Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under environmen......Cadmium (Cd) is an important environmental pollutant and is poisonous to most organisms. We aimed to unravel the mechanisms of Cd toxicity in the model water plant Ceratophyllum demersum exposed to low (nM) concentrations of Cd as are present in nature. Experiments were conducted under...... environmentally relevant conditions, including nature-like light and temperature cycles, and a low biomass to water ratio. We measured chlorophyll (Chl) fluorescence kinetics, oxygen exchange, the concentrations of reactive oxygen species and pigments, metal binding to proteins, and the accumulation of starch...... and metals. The inhibition threshold concentration for most parameters was 20 nM. Below this concentration, hardly any stress symptoms were observed. The first site of inhibition was photosynthetic light reactions (the maximal quantum yield of photosystem II (PSII) reaction centre measured as Fv /Fm , light...

  17. Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

    Directory of Open Access Journals (Sweden)

    Budnik Lygia T

    2012-01-01

    Full Text Available Abstract Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage. The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49, P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl

  18. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yinsheng, E-mail: yinshengli@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China); Tang, Hao; Hu, Yingxiu; Wang, Xiuhong; Ai, Xiaojie; Tang, Li [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China); Matthew, Cory [Institute of Agriculture & Environment, Massey University, Private Bag 11-222, Palmerston North 4442 (New Zealand); Cavanagh, Jo [Landcare Research, PO Box 40, Lincoln 7640 (New Zealand); Qiu, Jiangping [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2016-05-05

    Highlights: • Enrofloxacin (EF) and cadmium (Cd) were independently adsorbed in soils. • EF accelerated and increased Cd bioaccumulation in earthworms. • At high concentration EF (10 mg kg{sup −1}) was toxic to earthworms. • EF enhanced Cd induced oxidative stress, and increased burrowing and respiration. • EF did not affect the Cd induced increase in metallothionein in earthworms. - Abstract: Individual and combined effects of enrofloxacin (EF) and cadmium (Cd) on the earthworm Eisenia fetida at environmentally relevant concentrations were investigated. EF is a veterinary antibiotic; Cd is an impurity in phosphatic fertiliser. For both, residues may accumulate in farm soils. In laboratory tests, over 98% of spiked EF was adsorbed by farm soils, with a half-life >8 weeks. However, earthworms absorbed less than 20% of spiked EF. Earthworms in soil with EF concentration 10 mg kg{sup −1} soil experienced transient oxidative stress and exhibited reduced burrowing activity and respiration after an 8-week exposure; EF at 0.1 and 1.0 mg kg{sup −1} soil did not elicit toxicity symptoms. When both were added, Cd did not affect EF uptake, but each increment of spiked EF increased Cd bioaccumulation and associated oxidative stress of earthworms, and also caused decreased burrow length and CO{sub 2} production. However, metallothionein induction was not affected. The enhanced toxicity of Cd to earthworms in the presence of EF at low environmental concentrations may have implications for the health and reproductive success of earthworm populations and highlights the importance of understanding effects of antibiotic contamination of farm soils, and of awareness of environmental effects from interaction between multiple contaminants.

  19. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils

    International Nuclear Information System (INIS)

    Li, Yinsheng; Tang, Hao; Hu, Yingxiu; Wang, Xiuhong; Ai, Xiaojie; Tang, Li; Matthew, Cory; Cavanagh, Jo; Qiu, Jiangping

    2016-01-01

    Highlights: • Enrofloxacin (EF) and cadmium (Cd) were independently adsorbed in soils. • EF accelerated and increased Cd bioaccumulation in earthworms. • At high concentration EF (10 mg kg"−"1) was toxic to earthworms. • EF enhanced Cd induced oxidative stress, and increased burrowing and respiration. • EF did not affect the Cd induced increase in metallothionein in earthworms. - Abstract: Individual and combined effects of enrofloxacin (EF) and cadmium (Cd) on the earthworm Eisenia fetida at environmentally relevant concentrations were investigated. EF is a veterinary antibiotic; Cd is an impurity in phosphatic fertiliser. For both, residues may accumulate in farm soils. In laboratory tests, over 98% of spiked EF was adsorbed by farm soils, with a half-life >8 weeks. However, earthworms absorbed less than 20% of spiked EF. Earthworms in soil with EF concentration 10 mg kg"−"1 soil experienced transient oxidative stress and exhibited reduced burrowing activity and respiration after an 8-week exposure; EF at 0.1 and 1.0 mg kg"−"1 soil did not elicit toxicity symptoms. When both were added, Cd did not affect EF uptake, but each increment of spiked EF increased Cd bioaccumulation and associated oxidative stress of earthworms, and also caused decreased burrow length and CO_2 production. However, metallothionein induction was not affected. The enhanced toxicity of Cd to earthworms in the presence of EF at low environmental concentrations may have implications for the health and reproductive success of earthworm populations and highlights the importance of understanding effects of antibiotic contamination of farm soils, and of awareness of environmental effects from interaction between multiple contaminants.

  20. Effect of Methyl tert-Butyl Ether in Standard Tests for Mutagenicity and Environmental Toxicity

    Czech Academy of Sciences Publication Activity Database

    Vosáhlíková, M.; Cajthaml, Tomáš; Demnerová, K.; Pazlarová, Jarmila

    2006-01-01

    Roč. 21, č. 6 (2006), s. 599-605 ISSN 1520-4081 Institutional research plan: CEZ:AV0Z50200510 Keywords : toxicity * mtbe * ames test Subject RIV: EE - Microbiology, Virology Impact factor: 1.582, year: 2006

  1. An assessment of the environmental toxicity of hexavalent chromium in fish

    NARCIS (Netherlands)

    Putte, van der I.

    1981-01-01

    At present chromium is a common contaminant in surface waters in many countries. In water the metal may be present in the trivalent form (CrIII) or in the hexavalent form (CrVI), the latter of which is more toxic to aquatic organisms.
    The investigations presented in this thesis

  2. Environmental toxicity of Chemical Warfare Agents (CWAs) - MicrotoxTM and Spontaneous Locomotor Changes

    DEFF Research Database (Denmark)

    Storgaard, Morten Swayne; Sanderson, Hans; Baatrup, Erik

    After the 2nd World War the CWAs were prohibited by law and 11,000 tonnes of toxic agents were dumped in the Bornholm Basin east of Bornholm. The dumped chemical munitions have not reached attention from politicians and scientists until recently. During earlier projects, such as MERCW (2005...

  3. An indicator for effects of organic toxicants on lotic invertebrate communities: Independence of confounding environmental factors over an extensive river continuum

    International Nuclear Information System (INIS)

    Beketov, Mikhail A.; Liess, Matthias

    2008-01-01

    Distinguishing between effects of natural and anthropogenic environmental factors on ecosystems is a fundamental problem in environmental science. In river systems the longitudinal gradient of environmental factors is one of the most relevant sources of dissimilarity between communities that could be confounded with anthropogenic disturbances. To test the hypothesis that in macroinvertebrate communities the distribution of species' sensitivity to organic toxicants is independent of natural longitudinal factors, but depends on contamination with organic toxicants, we analysed the relationship between community sensitivity SPEAR organic (average community sensitivity to organic toxicants) and natural and anthropogenic environmental factors in a large-scale river system, from alpine streams to a lowland river. The results show that SPEAR organic is largely independent of natural longitudinal factors, but strongly dependent on contamination with organic toxicants (petrochemicals and synthetic surfactants). Usage of SPEAR organic as a stressor-specific longitude-independent measure will facilitate detection of community disturbance by organic toxicants. - Indicator for organic toxicants at community level can be independent of natural environmental factors

  4. Toxicity and environmental and economic performance of fly ash and recycled concrete aggregates use in concrete: A review.

    Science.gov (United States)

    Kurda, Rawaz; Silvestre, José D; de Brito, Jorge

    2018-04-01

    This paper presents an overview of previous studies on the environmental impact (EI) and toxicity of producing recycled concrete aggregates (RCA), fly ash (FA), cement, superplasticizer, and water as raw materials, and also on the effect of replacing cement and natural aggregates (NA) with FA and RCA, respectively, on the mentioned aspects. EI and toxicity were analysed simultaneously because considering concrete with alternative materials as sustainable depends on whether their risk assessment is high. Therefore, this study mainly focuses on the cradle-to-gate EI of one cubic meter of concrete, namely abiotic depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), photochemical ozone creation (POCP), acidification potential (AP), eutrophication potential (EP), non-renewable energy (PE-NRe) and renewable energy (PE-Re). In terms of toxicity, leachability (chemical and ecotoxicological characterization) was considered. The results also include the economic performance of these materials, and show that the incorporation of FA in concrete significantly decreases the EI and cost of concrete. Thus, the simultaneous incorporation of FA and RCA decrease the EI, cost, use of landfill space and natural resources extraction. Nonetheless, the leaching metals of FA decrease when they are incorporated in concrete. Relative to FA, the incorporation of RCA does not significantly affect the EI and cost of concrete, but it significantly reduces the use of landfill space and the need of virgin materials.

  5. Children's vulnerability to toxic chemicals: a challenge and opportunity to strengthen health and environmental policy.

    Science.gov (United States)

    Landrigan, Philip J; Goldman, Lynn R

    2011-05-01

    A key policy breakthrough occurred nearly twenty years ago with the discovery that children are far more sensitive than adults to toxic chemicals in the environment. This finding led to the recognition that chemical exposures early in life are significant and preventable causes of disease in children and adults. We review this knowledge and recommend a new policy to regulate industrial and consumer chemicals that will protect the health of children and all Americans, prevent disease, and reduce health care costs. The linchpins of a new US chemical policy will be: first, a legally mandated requirement to test the toxicity of chemicals already in commerce, prioritizing chemicals in the widest use, and incorporating new assessment technologies; second, a tiered approach to premarket evaluation of new chemicals; and third, epidemiologic monitoring and focused health studies of exposed populations.

  6. Environmental Guidance Program reference book: Toxic substances control act. Revision 7

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    This Reference Book contains a current copy of the Toxic Substances Control Act and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE staff for informational purposes only and should not be interpreted as legal guidance. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  7. Toxic Substances Control Act. Environmental Guidance Program Reference Book: Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-15

    This Reference Book contains a current copy of the Toxic Substances Control Act and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  8. Effect of Environmental Conditions and Toxic Compounds on the Locomotor Activity of Pediculus humanus capitis (Phthiraptera: Pediculidae).

    Science.gov (United States)

    Ortega-Insaurralde, I; Toloza, A C; Gonzalez-Audino, P; Mougabure-Cueto, G A; Alvarez-Costa, A; Roca-Acevedo, G; Picollo, M I

    2015-09-01

    In this work, we evaluated the effect of environmental variables such as temperature, humidity, and light on the locomotor activity of Pediculus humanus capitis. In addition, we used selected conditions of temperature, humidity, and light to study the effects of cypermethrin and N,N-diethyl-3-methylbenzamide (DEET) on the locomotor activity of head lice. Head lice increased their locomotor activity in an arena at 30°C compared with activity at 20°C. When we tested the influence of the humidity level, the locomotor activity of head lice showed no significant differences related to humidity level, both at 30°C and 20°C. Concerning light influence, we observed that the higher the intensity of light, the slower the movement of head lice. We also demonstrated that sublethal doses of toxics may alter locomotor activity in adults of head lice. Sublethal doses of cypermethrin induced hyperactivated responses in adult head lice. Sublethal doses of DEET evocated hypoactivated responses in head lice. The observation of stereotyped behavior in head lice elicited by toxic compounds proved that measuring locomotor activity in an experimental set-up where environmental conditions are controlled would be appropriate to evaluate compounds of biological importance, such as molecules involved in the host-parasite interaction and intraspecific relationships. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products.

    Science.gov (United States)

    Bondi, Cara Am; Marks, Julia L; Wroblewski, Lauren B; Raatikainen, Heidi S; Lenox, Shannon R; Gebhardt, Kay E

    2015-01-01

    Environmental chemical exposure is a major concern for consumers of packaged goods. The complexity of chemical nomenclature and wide availability of scientific research provide detailed information but lends itself to misinterpretation by the lay person. For the surfactant sodium lauryl sulfate (SLS), this has resulted in a misunderstanding of the environmental health impact of the chemical and statements in the media that are not scientifically supported. This review demonstrates how scientific works can be misinterpreted and used in a manner that was not intended by the authors, while simultaneously providing insight into the true environmental health impact of SLS. SLS is an anionic surfactant commonly used in consumer household cleaning products. For decades, this chemical has been developing a negative reputation with consumers because of inaccurate interpretations of the scientific literature and confusion between SLS and chemicals with similar names. Here, we review the human and environmental toxicity profiles of SLS and demonstrate that it is safe for use in consumer household cleaning products.

  10. Toxicity of Carbon Nanotubes and Its Implications for Occupational and Environmental Health

    Science.gov (United States)

    Lam, Chiu-wing; James, John T.

    2007-01-01

    Carbon nanotubes (CNTs), which possess desirable electrical and mechanical properties, potentially have wide industrial applications. CNTs exist in two forms, single-wall (SW) and multi-wall (MW). There has been great concern that if CNTs enter the work environment as suspended respirable particulate matter (PM), they could pose an inhalation hazard. The results of recent rodent studies have collectively shown that CNTs can produce inflammation, epithelioid granulomas, fibrosis, and biochemical changes in the lungs. Studies in mice given equal amounts of test dusts showed that CNTs were more toxic than quartz and produced lesions that became progressively more pronounced. These results have led us to recommend that respirable CNT dust be considered a serious occupational health hazard, and that exposure limits be established in the expectation of expanded industrial applications. CNTs, which are totally insoluble and fibrous, would be expected to be more biopersistent than mineral fibers. Biopersistence is the key factor determining the long-term toxicity of mineral fibers and certainly of CNTs too. We have postulated that the electrical and fibrous properties of CNTs also play important roles in the toxicity of CNTs in the lungs. Recently, MWCNTs have been found in ultrafine PM aggregates in combustion streams of methane, propane, and natural-gas flames of typical stoves; indoor and outdoor fine (fuels, and fine PM has been reported to be a major contributor to the induction of cardiopulmonary diseases by pollutants. Given that manufactured SWCNTs and/or MWCNTs have elicited pathological changes in the lungs and heart, we have postulated that exposure to combustion-generated MWCNTs in fine PM in the air may play a significant role in air pollution-related cardiopulmonary diseases. Therefore, CNTs from manufacturing and combustion sources in the environment could have adverse effects on human health.

  11. Cleaning up a toxic legacy: Environmental remediation of former uranium production sites in Central Asia

    International Nuclear Information System (INIS)

    Green, Andrew

    2016-01-01

    Nearly 60 abandoned uranium production sites dot the landscape and represent a hazard to the environment and inhabitants throughout rural Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. Each site poses a challenge for local and national governments that lack technical expertise and resources for remediation. The sites were used to produce uranium until the 1990s. They were built before proper regulatory infrastructure was in place to ensure eventual decommissioning, so leftover residues with long-lived radioactive and highly toxic chemical contaminants still pose substantial risks to the health of the public and the environment.

  12. Cleaning up a toxic legacy: Environmental remediation of former uranium production sites in Central Asia

    International Nuclear Information System (INIS)

    Green, Andrew

    2016-01-01

    Nearly 60 abandoned uranium production sites dot the landscape and represent a hazard to the environment and inhabitants throughout rural Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. Each site poses a challenge for local and national governments that lack technical expertise and resources for remediation. The sites were used to produce uranium until the 1990s. They were built before proper regulatory infrastructure was in place to ensure eventual decommissioning, so leftover residues with long-lived radioactive and highly toxic chemical contaminants still pose substantial risks to the health of the public and the environment

  13. Acute environmental toxicity and persistence of methyl salicylate: A chemical agent simulant. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, S.W.

    1994-06-01

    The interactions of methyl salicylate with plant foliage and soils were assessed using aerosol/vapor exposure methods. Measurements of deposition velocity and residence times for soils and foliar surfaces are reported. Severe plant contact toxicity was observed at foliar mass-loading levels above 4 {mu}g/cm{sup 2} leaf; however, recovery was noted after four to fourteen days. Methyl salicylate has a short-term effect on soil dehydrogenase activity, but not phosphatase activity. Results of the earthworm bioassay indicated only minimal effects on survival.

  14. Development and Evaluation of Reproductive and Developmental Toxicity Tests for Assessing the Hazards of Environmental Contaminants

    Science.gov (United States)

    1997-08-01

    diet of the animals, their dret was supplemented wtth Poly Vt vitamins by injecting the worms with vitamins three tunes a week. The weight of the...No Kl K2 K3 Bl B2 B3 Male 18 44 23 26 56 34 Clutch Weight (g) 2.64 14.07 5.07 5.72 14.50 8.94 % Normal 46.00 54.50 75.00 66.50 59.50 70.50...107. FEMALE REPRODUCTIVE TOXICITY EXPERIMENT: FINAL BREEDING AND EGG CLUTCH DATA AFTER DIRECT EXPOSURE TO EGLIN AFB SOIL Frog No. Kl K2 K3 Bl B2 B3

  15. Resistance may be an important mechanism by which marine microbes respond to environmental toxicants*1

    Science.gov (United States)

    Capriulo, Gerard M.; Flanzenbaum, Jeffrey; Wurster, Charles F.; Rowland, R. George

    1983-11-01

    The hypothesis, that at least certain marine microbial organisms respond to toxic stress by the development of resistance, was tested using the hypotric marine ciliate Euplotes vannus Muller as the test organism. Resistance to polychlorinated biphenyls (PCB, Aroclor 1254) was developed in E. vannus by exposing the animals to progressively higher PCB concentrations during a period of several months. The resistance to PCB persisted for at least 80 days (greater than 40 generations) after final exposure. This suggests either that genetic selection or persistent (lasting over many cell division cycles) phenotypic trait modification, possibly in the form of Dauermodification, had occurred. If resistance were widespread among marine microbial organisms in polluted environments it would be an important consideration in evaluating the long-term biological impact of both natural and man-induced chemical stress.

  16. Environmental contaminants in food. Volume II-part a: working papers. I. Priority setting of toxic substances for guiding monitoring programs. II. Five case studies of environmental food contamination

    International Nuclear Information System (INIS)

    1980-01-01

    This volume contains working papers written for Office of Technology Assessment (OTA) to assist in preparation of the report Environmental Contaminants in Food. The contents include: (1) Priority setting of toxic substances for guiding monitoring programs; and (2) Five case studies of environmental food contamination

  17. Whole Cell Biosensor Using Anabaena torulosa with Optical Transduction for Environmental Toxicity Evaluation

    Directory of Open Access Journals (Sweden)

    Ling Shing Wong

    2013-01-01

    Full Text Available A whole cell-based biosensor using Anabaena torulosa for the detection of heavy metals (Cu, Pb, and Cd, 2,4-dichlorophenoxyacetate (2,4-D, and chlorpyrifos was constructed. The cyanobacteria were entrapped on a cellulose membrane through filtration. Then, the membrane was dried and fixed into a cylindrical well, which was designed to be attached to an optical probe. The probe was connected to fluorescence spectrometer with optical fibre. The presence of the toxicants was indicated by the change of fluorescence emission, before and after the exposure. The linear detection ranges for Cu, Pb, and Cd were 2.5–10.0 µg/L, 0.5–5.0 µg/L, and 0.5–10.0 µg/L, respectively, while 2,4-D and chlorpyrifos shared similar linear ranges of 0.05–0.75 µg/L. The biosensor showed good sensitivity with the lowest limits of detection (LLD for Cu, Pb, Cd, 2,4-D and chlorpyrifos determined at 1.195 µg/L, 0.100 µg/L, 0.027 µg/L, 0.025 µg/L, and 0.025 µg/L, respectively. The overall reproducibility of the biosensor (n=3 was <±6.35%. The biosensor had been tested with different combinations of toxicants, with the results showing predominantly antagonistic responses. The results confirmed that the biosensor constructed in this report is suitable to be used in quantitative and qualitative detections of heavy metals and pesticides.

  18. Prediction of the relative toxicity of environmental toxins as a function of behavioral and non-behavioral endpoints

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    This study was conducted in order to examine the differential effects of behavioral and non-behavioral endpoints on the prediction of the relative toxicity of an environmental toxin. The effects of ionizing radiation were taken as the model for this evaluation. Forty rhesus monkeys were irradiated in groups of four at five different dose levels of high energy neuton and Bremsstrahlung radiations. Measures of behavioral performance, emesis and mortality were taken for each subject in order to test the hypotheses that behavioral indices would be more sensitive to gamma radiation than would physiological indices and that the physiological indices would be more sensitive to neutron radiations than would behavioral indices. The results supported these hypotheses

  19. Neurophysiological Effects of Chronic Indoor Environmental Toxic Mold Exposure on Children

    Directory of Open Access Journals (Sweden)

    Ebere C. Anyanwu

    2003-01-01

    Full Text Available The phenomenon of building-related diseases is attracting much research interest in recent years because of the extent to which it affects people with compromised immune systems, especially children. In this study, we reported the neurological findings in children who attended our Center because of chronic exposure to toxic molds. Clinical neurological and neurobehavioral questionnaires were administered with the cooperation of the children�s parents. The children then underwent a series of neurophysiological tests including electroencephalogram (EEG, brainstem evoked potential (BAEP, visual evoked potential (VEP, and somatosensory evoked potential (SSEP. The results showed high levels of abnormalities in the analysis of the subjective responses derived from the questionnaires. The EEG examination was abnormal in seven out of ten of the patients compared to the controls with only one in ten with episodes of bihemispheric sharp activity. In all the patients, there was frontotemporal theta wave ativity that seemed to indicate diffuse changes characteristic of metabolic encephalopathies. Also, there was highly marked 1 to 3 Hz delta activity that was asymmetrical in the right hemisphere of the brain in three out of ten patients. The waveforms of BAEP showed abnormalities in 90% of the patients with both 15’ and 31’ check sizes compared to none in the controls. There were significant delays in waveform V in a majority of the patients representing dysfunctional cognitive process and conductive hearing loss in both ears. VEP showed clear abnormalities in four in ten of the patients with P100 amplitudes and latencies decreased bilaterally. In all the patients, there was slowing of conduction in the right tibial at an average of 36.9 ms and there was significant decrease in amplitude of response at the proximal stimulation site. Sensory latencies obtained in the median, ulnar, and sural nerves bilaterally showed abnormalities in five out of ten

  20. Environmental and anthropogenic factors affecting the respiratory toxicity of volcanic ash in vitro

    Science.gov (United States)

    Tomašek, Ines; Horwell, Claire J.; Damby, David E.; Ayris, Paul M.; Barošová, Hana; Geers, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Clift, Martin J. D.

    2016-04-01

    Human exposure to inhalable volcanic ash particles following an eruption is a health concern, as respirable-sized particles can potentially contribute towards adverse respiratory health effects, such as the onset or exacerbation of respiratory and cardiovascular diseases. Although there is substantial information on the mineralogical properties of volcanic ash that may influence its biological reactivity, knowledge as to how external factors, such as air pollution, contribute to and augment the potential reactivity is limited. To determine the respiratory effects of volcanic particle interactions with anthropogenic pollution and volcanic gases we will experimentally assess: (i) physicochemical characteristics of volcanic ash relevant to respiratory toxicity; (ii) the effects of simultaneously inhaling anthropogenic pollution (i.e. diesel exhaust particles (DEP)) and volcanic ash (of different origins); (iii) alteration of volcanic ash toxicity following interaction with volcanic gases. In order to gain a first understanding of the biological impact of the respirable fraction of volcanic ash when inhaled with DEP in vitro, we used a sophisticated 3D triple cell co-culture model of the human alveolar epithelial tissue barrier. The multi-cellular system was exposed to DEP [0.02 mg/mL] and then exposed to either a single or repeated dose of well-characterised respirable volcanic ash (0.26 ± 0.09 or 0.89 ± 0.29 μg/cm2, respectively) from the Soufrière Hills volcano, Montserrat for a period of 24 hours using a pseudo-air liquid interface approach. Cultures were subsequently assessed for adverse biological endpoints including cytotoxicity, oxidative stress and (pro)-inflammatory responses. Results indicated that the combination of DEP and respirable volcanic ash at sub-lethal concentrations incited a significant release of pro-inflammatory markers that was greater than the response for either DEP or volcanic ash, independently. Further work is planned, to determine if

  1. Environmental technology applications: fact file on toxic contaminants in industrial waste process streams

    Energy Technology Data Exchange (ETDEWEB)

    Newkirk, H.W.

    1977-05-11

    This report is a compendium of facts related to chemical materials present in industrial waste process streams which have already been declared or are being evaluated as hazardous under the Toxic Substances Control Act. Since some 400 chemicals are presently covered by consensus standards, the substances reviewed are only those considered to be a major threat to public health and welfare by Federal and State regulatory agencies. For each hazardous material cited, the facts relate, where possible, to an identification of the stationary industrial sources, the kind of waste stream impacted, proposed regulations and established effluent standards, the volume of emissions produced each year, the volume of emissions per unit of industrial product produced, present clean-up capabilities, limitations, and costs. These data should be helpful in providing information for the assessment of potential problems, should be of use to the manufacturers of pollution control equipment or of chemicals for pollution control, should be of use to the operators or potential operators of processes which produce pollutants, and should help to define industry-wide emission practices and magnitudes.

  2. Occupational and environmental hazard assessments for the isolation, purification and toxicity testing of cyanobacterial toxins

    Directory of Open Access Journals (Sweden)

    Wickramasinghe Wasantha A

    2009-11-01

    Full Text Available Abstract Cyanobacteria can produce groups of structurally and functionally unrelated but highly potent toxins. Cyanotoxins are used in multiple research endeavours, either for direct investigation of their toxicologic properties, or as functional analogues for various biochemical and physiological processes. This paper presents occupational safety guidelines and recommendations for personnel working in field, laboratory or industrial settings to produce and use purified cyanotoxins and toxic cyanobacteria, from bulk harvesting of bloom material, mass culture of laboratory isolates, through routine extraction, isolation and purification. Oral, inhalational, dermal and parenteral routes are all potential occupational exposure pathways during the various stages of cyanotoxin production and application. Investigation of toxicologic or pharmacologic properties using in vivo models may present specific risks if radiolabelled cyanotoxins are employed, and the potential for occupational exposure via the dermal route is heightened with the use of organic solvents as vehicles. Inter- and intra-national transport of living cyanobacteria for research purposes risks establishing feral microalgal populations, so disinfection of culture equipment and destruction of cells by autoclaving, incineration and/or chlorination is recommended in order to prevent viable cyanobacteria from escaping research or production facilities.

  3. Occupational and environmental hazard assessments for the isolation, purification and toxicity testing of cyanobacterial toxins

    Science.gov (United States)

    2009-01-01

    Cyanobacteria can produce groups of structurally and functionally unrelated but highly potent toxins. Cyanotoxins are used in multiple research endeavours, either for direct investigation of their toxicologic properties, or as functional analogues for various biochemical and physiological processes. This paper presents occupational safety guidelines and recommendations for personnel working in field, laboratory or industrial settings to produce and use purified cyanotoxins and toxic cyanobacteria, from bulk harvesting of bloom material, mass culture of laboratory isolates, through routine extraction, isolation and purification. Oral, inhalational, dermal and parenteral routes are all potential occupational exposure pathways during the various stages of cyanotoxin production and application. Investigation of toxicologic or pharmacologic properties using in vivo models may present specific risks if radiolabelled cyanotoxins are employed, and the potential for occupational exposure via the dermal route is heightened with the use of organic solvents as vehicles. Inter- and intra-national transport of living cyanobacteria for research purposes risks establishing feral microalgal populations, so disinfection of culture equipment and destruction of cells by autoclaving, incineration and/or chlorination is recommended in order to prevent viable cyanobacteria from escaping research or production facilities. PMID:19925679

  4. Gene expression profiling in zebrafish embryos exposed to diclofenac, an environmental toxicant.

    Science.gov (United States)

    De Felice, Bruna; Copia, Luisa; Guida, Marco

    2012-03-01

    Pharmaceuticals are continually released in the environment and therefore pollution from drugs is a pressing problem in the environment. Diclofenac, 2-[(2,6-dichlorophenyl)amino]phenylacetic acid is a FDA approved non-steroidal anti-inflammatory drug (NSAID) for the treatment of inflammation. This pharmaceutical has been found as pollutant in superficial waters. Danio rerio (zebrafish) embryo has been used as a model organism for acute pollutant toxicity tests in order to identify morphological alterations in development and death rate. Through the combination of mRNA differential display and quantitative Real Time experiments, we analyzed the alterations of gene expression in zebrafish embryos left to develop in the presence of diclofenac and thereby assess the molecular mechanism involved in ecotoxicity of diclofenac polluted waters. This approach, in embryos exposed to 1.25 mg/l drug for 48 h, allowed identifying 36 different genes, with both known and unknown functions, whose transcription is differentially regulated. The identity and ontological classification of these genes is presented. The wide variety of functional classes of transcripts isolated in this screen reflects the diverse spectrum of influences operating across diclofenac exposure. Of these 36 genes, several have been selected for detailed quantitative Real Time analysis to validate the screen. Our results, for the first time, provide an insight into some of the varied and novel molecular networks following zebrafish exposure to diclofenac polluted waters.

  5. [Concepts for the regulation of mixtures of toxic pollutants in environmental hygiene].

    Science.gov (United States)

    Csicsaky, M J

    1998-06-01

    In view of the increasing accumulation of large-scale livestock production facilities in the western parts of Lower Saxony the question rises how ecology and economy can be conciliated and how the protection of human health can be assured. Based on existing legislation this is hard to achieve because of the weak legal position of the administration when trying to prohibit the further expansion of livestock production as opposed to the strong legal position of owners and investors. Presently there is no agreement within the scientific community on safe limits for airborne pathogens and it is quite obvious that thresholds for peak concentrations do not solve the problem of background level exposures. Apart from the unsatisfactory current practise to licence farm animal units in the outskirts of existing villages only, in future the introduction of the EC Environmental Management and Auditing Scheme (EMAS) in animal production may improve the situation. This management system is intended to permanently reduce the environmental impact of a production site and implements the ALARA-PRINCIPLE (as low as reasonably achievable) which is known from protection measures against radiation. As the implementation of the EMAS so far works only on a voluntary basis, an incentive is needed. If dealers and consumers give preference to products from producers having adopted the EMAS, this would be a very efficient incentive. Before this could be put into practise, however, the EMAS criteria originally designed for industrial production sites will have to be adapted to the special conditions of animal production.

  6. The interaction of genetics and environmental toxicants in amyotrophic lateral sclerosis: results from animal models

    Institute of Scientific and Technical Information of China (English)

    Roger B. Sher

    2017-01-01

    Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that results in the progres-sive death of motor neurons, leading to paralysis and eventual death. There is presently no cure for ALS, and only two drugs are available, neither of which provide significant extension of life. The wide variation in onset and progression of the disease, both in sporadic and even in strongly penetrant monogenic famil-ial forms of ALS, indicate that in addition to background genetic variation impacting the disease process, environmental exposures are likely contributors. Epidemiological evidence worldwide implicates exposures to bacterial toxins, heavy metals, pesticides, and trauma as probable environmental factors. Here, we review current advances in gene-environment interactions in ALS animal models. We report our recent discov-eries in a zebrafish model of ALS in relation to exposure to the cyanobacterial toxin BMAA, and discuss several results from mouse models that show interactions with exposure to mercury and statin drugs, both leading to acceleration of the disease process. The increasing research into this combinatorial gene-environ-ment process is just starting, but shows early promise to uncover the underlying biochemical pathways that instigate the initial motor neuron defects and lead to their rapidly progressive dysfunction.

  7. The effect of environmental hypercapnia and size on nitrite toxicity in the striped catfish (Pangasianodon hypophthalmus)

    DEFF Research Database (Denmark)

    Hvas, Malthe; Damsgaard, Christian; Gam, Le Thi Hong

    2016-01-01

    Striped catfish (Pangasianodon hypophthalmus) are farmed intensively at high stocking densities in Vietnam where they are likely to encounter environmental hypercapnia as well as occasional high levels of aquatic nitrite. Nitrite competes with Cl- for uptake at the branchial HCO3-/Cl- exchanger, ...... the ambient concentration, while small fish did not. Small P. hypophthalmus instead had significantly higher plasma [nitrate], and haemoglobin concentrations, revealing greater capacity for detoxifying nitrite by oxidising it to nitrate.......Striped catfish (Pangasianodon hypophthalmus) are farmed intensively at high stocking densities in Vietnam where they are likely to encounter environmental hypercapnia as well as occasional high levels of aquatic nitrite. Nitrite competes with Cl- for uptake at the branchial HCO3-/Cl- exchanger...... to a reduced nitrite uptake. To assess the effect of hypercapnia on nitrite uptake, fish were cannulated in the dorsal aorta, allowing repeated blood sampling for measurements of haemoglobin derivatives, plasma ions and acid-base status during exposure to 0.9 mM nitrite alone and in combination with acute...

  8. Safflower oil: an integrated assessment of phytochemistry, antiulcerogenic activity, and rodent and environmental toxicity

    Directory of Open Access Journals (Sweden)

    Walber Toma

    Full Text Available Gastric ulcers are a significant medical problem and the development of complications lead to significant mortality rates worldwide. In Brazil, Carthamus tinctorius L., Asteraceae, seeds essential oil, the safflower oil, is currently used as a thermogenic compound and as treatment for problems related to the cardiovascular system. In this study, by Raman spectroscopy, it was shown that oleic and linoleic acids are the compounds present in higher concentrations in the safflower oil. We demonstrated that safflower oil (750 mg/kg, p.o. decrease the ulcerogenic lesions in mice after the administration of hydrochloric acid-ethanol. The gastric ulcers induced by non-steroidal anti-inflammatory drug (NSAID in mice treated with cholinomimetics were treated with four different doses of safflower oil, of which, the dose of 187.5 mg/kg (p.o. showed significant antiulcerogenic properties (**p < 0.01. Moreover, the safflower oil at doses of 187.5 mg/kg (i.d. increased the pH levels, gastric volume (**p < 0.01 and gastric mucus production (***p < 0.001, and decreased the total gastric acid secretion (***p < 0.001. The acute toxicity tests showed that safflower oil (5.000 mg/kg, p.o. had no effect on mortality or any other physiological parameter. Ecotoxicological tests performed using Daphnia similis showed an EC50 at 223.17 mg/l, and therefore safflower oil can be considered “non-toxic” based on the directive 93/67/EEC on risk assessment for new notified substances by European legislation. These results indicate that the antiulcer activity of Safflower oil may be due to cytoprotective effects, which serve as support for new scientific studies related to this pathology.

  9. Intracellular conversion of environmental nitrate and nitrite to nitric oxide with resulting developmental toxicity to the crustacean Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Bethany R Hannas

    2010-08-01

    Full Text Available Nitrate and nitrite (jointly referred to herein as NO(x are ubiquitous environmental contaminants to which aquatic organisms are at particularly high risk of exposure. We tested the hypothesis that NO(x undergo intracellular conversion to the potent signaling molecule nitric oxide resulting in the disruption of endocrine-regulated processes.These experiments were performed with insect cells (Drosophila S2 and whole organisms Daphnia magna. We first evaluated the ability of cells to convert nitrate (NO(3(- and nitrite (NO(2(- to nitric oxide using amperometric real-time nitric oxide detection. Both NO(3(- and NO(2(- were converted to nitric oxide in a substrate concentration-dependent manner. Further, nitric oxide trapping and fluorescent visualization studies revealed that perinatal daphnids readily convert NO(2(- to nitric oxide. Next, daphnids were continuously exposed to concentrations of the nitric oxide-donor sodium nitroprusside (positive control and to concentrations of NO(3(- and NO(2(-. All three compounds interfered with normal embryo development and reduced daphnid fecundity. Developmental abnormalities were characteristic of those elicited by compounds that interfere with ecdysteroid signaling. However, no compelling evidence was generated to indicate that nitric oxide reduced ecdysteroid titers.Results demonstrate that nitrite elicits developmental and reproductive toxicity at environmentally relevant concentrations due likely to its intracellular conversion to nitric oxide.

  10. Occurrences of the toxic dinoflagellate Ostreopsis ovata in relation with environmental factors in Kerkennah Island (Southern coast of Tunisia

    Directory of Open Access Journals (Sweden)

    Mounir Ben brahim

    2015-08-01

    Full Text Available Objective: To study the seasonal and monthly variability of the toxic dinoflagellate Ostreopsis ovata (O. ovata in relation to environmental parameters in Kerkennah Island. Methods: Three water samples replicate of one-litter were taken daily for ten consecutive days on 12 months. All sampling water was kept in the dark at ambient temperature until their microscopic observation. Environmental variables such as salinity and temperature were measured in the field concomitantly as phytoplankton sampling. Nutrients (ammonium, nitrite, nitrate, phosphate and silicate were analysed in laboratory with Auto-analyser Luebbe type. Cell identification and enumeration in water samples were performed with an inverted microscope after the sedimentation. Results: The highest abundance of O. ovata was recorded in summer. Analysis of variance showed significant difference of abundance between seasons, whereas no significant difference for month was detected. Factorial analysis ordination showed a positive correlation of Ostreopsis mainly with temperature and low correlation with nitrite and nitrate whereas the second axis (with 26.30% of variance showed that Ostreopsis was correlated with temperature and salinity. Conclusions: The maximum abundance of Ostreopsis was reached in summer when temperature was high and a low relationship between O. ovata and nutrient was detected.

  11. TetrakisHydroxymethylPhosphonium Sulfate (THPS), a new industrial biocide with low environmental toxicity

    International Nuclear Information System (INIS)

    Downward, B.L.; Talbot, R.E.; Haack, T.K.

    1997-01-01

    THPS is a new biocide active designed for use in a variety of environmentally sensitive applications such as industrial cooling systems and oilfield situations. EPA registration has recently been achieved thus permitting, for the first time, the use of THPS based biocides in the US. This paper reviews the chemistry of THPS and reports a variety of case histories where THPS has successfully been used for the control of bacteria, algae and fungi in industrial cooling systems in Western Europe. An extensive data package, including field applications and laboratory studies, is available for THPS providing many exciting opportunities for this product in the US. Case studies are presented for a cooling system in a fuel reprocessing plant, a process water system for a textile plant, and cooling systems for a chemical plant and a confectionary site

  12. Temporal assessment of copper speciation, bioavailability and toxicity in UK freshwaters using chemical equilibrium and biotic ligand models: Implications for compliance with copper environmental quality standards.

    Science.gov (United States)

    Lathouri, Maria; Korre, Anna

    2015-12-15

    Although significant progress has been made in understanding how environmental factors modify the speciation, bioavailability and toxicity of metals such as copper in aquatic environments, the current methods used to establish water quality standards do not necessarily consider the different geological and geochemical characteristics of a given site and the factors that affect copper fate, bioavailability potential and toxicity. In addition, the temporal variation in the concentration and bioavailable metal fraction is also important in freshwater systems. The work presented in this paper illustrates the temporal and seasonal variability of a range of water quality parameters, and Cu speciation, bioavailability and toxicity at four freshwaters sites in the UK. Rivers Coquet, Cree, Lower Clyde and Eden (Kent) were selected to cover a broad range of different geochemical environments and site characteristics. The monitoring data used covered a period of around six years at almost monthly intervals. Chemical equilibrium modelling was used to study temporal variations in Cu speciation and was combined with acute toxicity modelling to assess Cu bioavailability for two aquatic species, Daphnia magna and Daphnia pulex. The estimated copper bioavailability, toxicity levels and the corresponding ecosystem risks were analysed in relation to key water quality parameters (alkalinity, pH and DOC). Although copper concentrations did not vary much during the sampling period or between the seasons at the different sites; copper bioavailability varied markedly. In addition, through the chronic-Cu BLM-based on the voluntary risk assessment approach, the potential environmental risk in terms of the chronic toxicity was assessed. A much higher likelihood of toxicity effects was found during the cold period at all sites. It is suggested that besides the metal (copper) concentration in the surface water environment, the variability and seasonality of other important water quality

  13. Introducing Environmental Toxicology in Instructional Labs: The Use of a Modified Amphibian Developmental Toxicity Assay to Support Inquiry-Based Student Projects

    Science.gov (United States)

    Sauterer, Roger; Rayburn, James R.

    2012-01-01

    Introducing students to the process of scientific inquiry is a major goal of high school and college labs. Environmental toxins are of great concern and public interest. Modifications of a vertebrate developmental toxicity assay using the frog Xenopus laevis can support student-initiated toxicology experiments that are relevant to humans. Teams of…

  14. Notification: Background Investigation Services New Assignment Notification: EPA’s Efforts to Incorporate Environmental Justice Into Clean Air Act Inspections for Air Toxics

    Science.gov (United States)

    The purpose of this memorandum is to notify you that the EPA OIG plans to begin the preliminary research phase of an evaluation of the U.S. EPA's efforts to incorporate environmental justice into Clean Air Act inspections for air toxics.

  15. Zebrafish transgenic line huORFZ is an effective living bioindicator for detecting environmental toxicants.

    Directory of Open Access Journals (Sweden)

    Hung-Chieh Lee

    Full Text Available Reliable animal models are invaluable for monitoring the extent of pollution in the aquatic environment. In this study, we demonstrated the potential of huORFZ, a novel transgenic zebrafish line that harbors a human upstream open reading frame of the chop gene fused with GFP reporter, as an animal model for monitoring environmental pollutants and stress-related cellular processes. When huORFZ embryos were kept under normal condition, no leaked GFP signal could be detected. When treated with hazardous chemicals, including heavy metals and endocrine-disrupting chemicals near their sublethal concentrations (LC50, huORFZ embryos exhibited different tissue-specific GFP expression patterns. For further analysis, copper (Cu2+, cadmium (Cd2+ and Chlorpyrifos were applied. Cu2+ triggered GFP responses in skin and muscle, whereas Cd2+ treatment triggered GFP responses in skin, olfactory epithelium and pronephric ducts. Moreover, fluorescence intensity, as exhibited by huORFZ embryos, was dose-dependent. After surviving treated embryos were returned to normal condition, survival rates, as well as TUNEL signals, returned to pretreatment levels with no significant morphological defects observed. Such results indicated the reversibility of treatment conditions used in this study, as long as embryos survived such conditions. Notably, GFP signals decreased along with recovery, suggesting that GFP signaling of huORFZ embryos likely reflected the overall physiological condition of the individual. To examine the performance of the huORFZ line under real-world conditions, we placed huORFZ embryos in different river water samples. We found that the huORFZ embryos correctly detected the presence of various kinds of pollutants. Based on these findings, we concluded that such uORFchop-based system can be integrated into a first-line water alarm system monitoring the discharge of hazardous pollutants.

  16. Zebrafish Transgenic Line huORFZ Is an Effective Living Bioindicator for Detecting Environmental Toxicants

    Science.gov (United States)

    Chu, Chien; Li, Hong-Ping; Tsai, Huai-Jen

    2014-01-01

    Reliable animal models are invaluable for monitoring the extent of pollution in the aquatic environment. In this study, we demonstrated the potential of huORFZ, a novel transgenic zebrafish line that harbors a human upstream open reading frame of the chop gene fused with GFP reporter, as an animal model for monitoring environmental pollutants and stress-related cellular processes. When huORFZ embryos were kept under normal condition, no leaked GFP signal could be detected. When treated with hazardous chemicals, including heavy metals and endocrine-disrupting chemicals near their sublethal concentrations (LC50), huORFZ embryos exhibited different tissue-specific GFP expression patterns. For further analysis, copper (Cu2+), cadmium (Cd2+) and Chlorpyrifos were applied. Cu2+ triggered GFP responses in skin and muscle, whereas Cd2+ treatment triggered GFP responses in skin, olfactory epithelium and pronephric ducts. Moreover, fluorescence intensity, as exhibited by huORFZ embryos, was dose-dependent. After surviving treated embryos were returned to normal condition, survival rates, as well as TUNEL signals, returned to pretreatment levels with no significant morphological defects observed. Such results indicated the reversibility of treatment conditions used in this study, as long as embryos survived such conditions. Notably, GFP signals decreased along with recovery, suggesting that GFP signaling of huORFZ embryos likely reflected the overall physiological condition of the individual. To examine the performance of the huORFZ line under real-world conditions, we placed huORFZ embryos in different river water samples. We found that the huORFZ embryos correctly detected the presence of various kinds of pollutants. Based on these findings, we concluded that such uORFchop-based system can be integrated into a first-line water alarm system monitoring the discharge of hazardous pollutants. PMID:24594581

  17. Switching slips. Building blocks for a robust environmental policy for the 21st century; Wissels omzetten. Bouwstenen voor een robuust milieubeleid voor de 21e eeuw

    Energy Technology Data Exchange (ETDEWEB)

    Hoogervorst, N.; Hajer, M.; Dietz, F.; Timmerhuis, J.; Kruitwagen, S.

    2013-06-15

    With this 'signal report', PBL (Netherlands Environmental Assessment Agency) offers building blocks for a robust environmental policy for the twentyfirst century, such as changes in consumer behavior, new coalitions of interests and stakeholders, and the establishment of an investment fund for eco-innovation. Which track does the Netherlands want to follow? With this essay, PBL is calling for a broad public debate on this issue [Dutch] In dit signalenrapport reikt het PBL (Planbureau voor de Leefomgeving) bouwstenen aan voor een robuust milieubeleid voor de eenentwintigste eeuw, zoals gedragsverandering van consumenten, nieuwe coalities van belangen en betrokkenen, en de oprichting van een investeringsfonds voor eco-innovatie. Welk spoor wil Nederland bewandelen? Met dit essay roept het PBL op tot een breed maatschappelijk debat over deze vraag.

  18. Switching slips. Building blocks for a robust environmental policy for the 21st century; Wissels omzetten. Bouwstenen voor een robuust milieubeleid voor de 21e eeuw

    Energy Technology Data Exchange (ETDEWEB)

    Hoogervorst, N.; Hajer, M.; Dietz, F.; Timmerhuis, J.; Kruitwagen, S.

    2013-06-15

    With this 'signal report', PBL (Netherlands Environmental Assessment Agency) offers building blocks for a robust environmental policy for the twentyfirst century, such as changes in consumer behavior, new coalitions of interests and stakeholders, and the establishment of an investment fund for eco-innovation. Which track does the Netherlands want to follow? With this essay, PBL is calling for a broad public debate on this issue [Dutch] In dit signalenrapport reikt het PBL (Planbureau voor de Leefomgeving) bouwstenen aan voor een robuust milieubeleid voor de eenentwintigste eeuw, zoals gedragsverandering van consumenten, nieuwe coalities van belangen en betrokkenen, en de oprichting van een investeringsfonds voor eco-innovatie. Welk spoor wil Nederland bewandelen? Met dit essay roept het PBL op tot een breed maatschappelijk debat over deze vraag.

  19. Acute environmental toxicity and persistence of DEM, a chemical agent simulant: Diethyl malonate. [Diethyl malonate

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, Shu-mei W.; Van Voris, P.; Wentsel, R.S.

    1990-05-01

    The purpose of the following chemical simulant studies is to assess the potential acute environmental effects and persistence of diethyl malonate (DEM). Deposition velocities for DEM to soil surfaces ranged from 0.04 to 0.2 cm/sec. For foliar surfaces, deposition velocities ranged from 0.0002 cm/sec at low air concentrations to 0.05 cm/sec for high dose levels. The residence times or half-lives of DEM deposited to soils was 2 h for the fast component and 5 to 16 h for the residual material. DEM deposited to foliar surfaces also exhibited biphasic depuration. The half-life of the short residence time component ranged from 1 to 3 h, while the longer time component had half-times of 16 to 242 h. Volatilization and other depuration mechanisms reduce surface contaminant levels in both soils and foliage to less than 1% of initial dose within 96 h. DEM is not phytotoxic at foliar mass loading levels of less than 10 {mu}m/cm{sup 2}. However, severe damage is evident at mass loading levels in excess of 17 {mu}g/cm{sup 2}. Tall fescue and sagebrush were more affected than was short-needle pine, however, mass loading levels were markedly different. Regrowth of tall fescue indicated that the effects of DEM are residual, and growth rates are affected only at higher mass loadings through the second harvest. Results from in vitro testing of DEM indicated concentrations below 500 {mu}g/g dry soil generally did not negatively impact soil microbial activity. Short-term effects of DEM were more profound on soil dehydrogenase activity than on soil phosphatase activity. No enzyme inhibition or enhancement was observed after 28 days in incubation. Results of the earthworm bioassay indicate survival to be 86 and 66% at soil doses of 107 and 204 {mu}g DEM/cm{sup 2}, respectively. At higher dose level, activity or mobility was judged to be affected in over 50% of the individuals. 21 refs., 10 figs., 15 tabs.

  20. Optimization of organic contaminant and toxicity testing analytical procedures for estimating the characteristics and environmental significance of natural gas processing plant waste sludges

    International Nuclear Information System (INIS)

    Novak, N.

    1990-10-01

    The Gas Plant Sludge Characterization Phase IIB program is a continuation of the Canadian Petroleum Association's (CPA) initiatives to characterize sludge generated at gas processing plants. The objectives of the Phase IIB project were to develop an effective procedure for screening waste sludges or centrifuge/leachate generated from sludge samples for volatile, solvent-soluble and water-soluble organics; verify the reproducibility of the three aquatic toxicity tests recommended as the battery of tests for determining the environmental significance of sludge centrifugates or leachates; assess the performance of two terrestrial toxicity tests in determining the environmental significance of whole sludge samples applied to soil; and to assess and discuss the reproducibility and cost-effectiveness of the sampling and analytical techniques proposed for the overall sludge characterization procedure. Conclusions and recommendations are provided for sludge collection, preparation and distribution, organic analyses, toxicity testing, project management, and procedure standardization. The three aquatic and two terrestrial toxicity tests proved effective in indicating the toxicity of complex mixtures. 27 refs., 3 figs., 59 tabs

  1. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  2. Evaluation on subcellular partitioning and biodynamics of pulse copper toxicity in tilapia reveals impacts of a major environmental disturbance.

    Science.gov (United States)

    Ju, Yun-Ru; Yang, Ying-Fei; Tsai, Jeng-Wei; Cheng, Yi-Hsien; Chen, Wei-Yu; Liao, Chung-Min

    2017-07-01

    Fluctuation exposure of trace metal copper (Cu) is ubiquitous in aquatic environments. The purpose of this study was to investigate the impacts of chronically pulsed exposure on biodynamics and subcellular partitioning of Cu in freshwater tilapia (Oreochromis mossambicus). Long-term 28-day pulsed Cu exposure experiments were performed to explore subcellular partitioning and toxicokinetics/toxicodynamics of Cu in tilapia. Subcellular partitioning linking with a metal influx scheme was used to estimate detoxification and elimination rates. A biotic ligand model-based damage assessment model was used to take into account environmental effects and biological mechanisms of Cu toxicity. We demonstrated that the probability causing 50% of susceptibility risk in response to pulse Cu exposure in generic Taiwan aquaculture ponds was ~33% of Cu in adverse physiologically associated, metabolically active pool, implicating no significant susceptibility risk for tilapia. We suggest that our integrated ecotoxicological models linking chronic exposure measurements with subcellular partitioning can facilitate a risk assessment framework that provides a predictive tool for preventive susceptibility reduction strategies for freshwater fish exposed to pulse metal stressors.

  3. Latex peptidases of Calotropis procera for dehairing of leather as an alternative to environmentally toxic sodium sulfide treatment.

    Science.gov (United States)

    Lopéz, Laura M I; Viana, Carolina A; Errasti, María E; Garro, María L; Martegani, José E; Mazzilli, Germán A; Freitas, Cléverson D T; Araújo, Ídila M S; da Silva, Rafaela O; Ramos, Márcio V

    2017-09-01

    Dehairing of crude leather is a critical stage performed at the beginning of its processing to obtain industrially useful pieces. Tanneries traditionally apply a chemical process based on sodium sulfide. Since this chemical reactive is environmentally toxic and inefficiently recycled, innovative protocols for reducing or eliminating its use in leather depilation are welcomed. Therefore, latex peptidases from Calotropis procera (CpLP) and Cryptostegia grandiflora (CgLP) were assayed for this purpose. Enzyme activity on substrates representative of skin such as hide powder azure (U HPA ), elastin (U E ), azocollagen (U AZOCOL ), keratin (U K ), and epidermis (U EP ) was determined, while depilation activity was assayed on cow hide. Only CpLP was active against keratin (13.4 U K ) and only CgLP was active against elastin (0.12 U E ). CpLP (93.0 U HPA , 403.6 U AZOCOL , 36.3 U EP ) showed higher activity against the other substrates than CgLP (47.6 U HPA , 261.5 U AZOCOL , 8.5 U EP ). In pilot assays, CpLP (0.05% w/v with sodium sulfite 0.6% w/v as activator) released hairs from cow hide pieces. Macroscopic and microscopic analyses of the hide revealed that the dehairing process was complete and the leather structure was preserved. The proteolytic system of C. procera is a suitable bioresources to be exploited by tanneries.

  4. Critical comparison of intravenous injection of TiO2 nanoparticles with waterborne and dietary exposures concludes minimal environmentally-relevant toxicity in juvenile rainbow trout Oncorhynchus mykiss

    International Nuclear Information System (INIS)

    Boyle, David; Al-Bairuty, Genan A.; Henry, Theodore B.; Handy, Richard D.

    2013-01-01

    A critical comparison of studies that have investigated tissue accumulation and toxicity of TiO 2 -NPs in fish is necessary to resolve inconsistencies. The present study used identical TiO 2 -NPs, toxicological endpoints, and fish (juvenile rainbow trout Oncorhynchus mykiss) as previous studies that investigated waterborne and dietary toxicity of TiO 2 -NPs, and conducted a critical comparison of results after intravenous caudal-vein injection of 50 μg of TiO 2 -NPs and bulk TiO 2 . Injected TiO 2 -NPs accumulated only in kidney (94% of measured Ti) and to a lesser extent in spleen; and injected bulk TiO 2 was found only in kidney. No toxicity of TiO 2 was observed in kidney, spleen, or other tissues. Critical comparison of these data with previous studies indicates that dietary and waterborne exposures to TiO 2 -NPs do not lead to Ti accumulation in internal tissues, and previous reports of minor toxicity are inconsistent or attributable to respiratory distress resulting from gill occlusion during waterborne exposure. -- Highlights: •Critical comparison of TiO 2 -NP toxicity studies in rainbow trout. •No evidence of TiO 2 -NP absorption in internal tissues. •Conclude minimal environmentally relevant toxicity of TiO 2 -NPs in rainbow trout. -- Critical evaluation of directly comparable investigations of TiO 2 -NP toxicity by waterborne, dietary, and intravenous injection exposures conclude minimal toxicity in juvenile rainbow trout

  5. Epidural block

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000484.htm Epidural block - pregnancy To use the sharing features on this page, please enable JavaScript. An epidural block is a numbing medicine given by injection (shot) ...

  6. Host Response to Environmental Hazards: Using Literature, Bioinformatics, and Computation to Derive Candidate Biomarkers of Toxic Industrial Chemical Exposure

    Science.gov (United States)

    2015-10-01

    military threat chemicals with adverse health effects and clinical outcomes to improve diagnostic potential after exposure to toxic industrial...end organ injury following chemical exposures in the field. Markers of end-organ injury and toxicity and other health effects markers, particularly...Biomarkers of Toxic Industrial Chemical Exposure Major Jonathan D. Stallings *1 , Danielle L. Ippolito 1 , Anders Wallqvist 2 , B. Claire McDyre 3 , and

  7. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  8. Scenario-targeted toxicity assessment through multiple endpoint bioassays in a soil posing unacceptable environmental risk according to regulatory screening values.

    Science.gov (United States)

    Rodriguez-Ruiz, A; Etxebarria, J; Boatti, L; Marigómez, I

    2015-09-01

    Lanestosa is a chronically polluted site (derelict mine) where the soil (Lanestosa (LA) soil) exceeds screening values (SVs) of regulatory policies in force (Basque Country; Europe) for Zn, Pb and Cd. A scenario-targeted toxicity assessment was carried out on the basis of a multi-endpoint bioassay approach. Acute and chronic toxicity bioassays were conducted with selected test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates and with bioaccumulation studies in earthworms. Besides, the toxicity profile was compared with that of the mine runoff (RO) soil and of a fresh artificially polluted soil (LAAPS) resembling LA soil pollutant profile. Extractability studies in LA soil revealed that Pb, Zn and Cd were highly available for exchange and/or release into the environment. Indeed, Pb and Zn were accumulated in earthworms and LA soil resulted to be toxic. Soil respiration, V. fischeri, vegetative and developmental cycles of D. discoideum and survival and juvenile production of E. fetida were severely affected. These results confirmed that LA soil had unacceptable environmental risk and demanded intervention. In contrast, although Pb and Zn concentrations in RO soil revealed also unacceptable risk, both metal extractability and toxicity were much lower than in LA soil. Thus, within the polluted site, the need for intervention varied between areas that posed dissimilar risk. Besides, since LAAPS, with a high exchangeable metal fraction, was the most toxic, ageing under in situ natural conditions seemingly contributed to attenuate LA soil risk. As a whole, combining multi-endpoint bioassays with scenario-targeted analysis (including leaching and ageing) provides reliable risk assessment in soils posing unacceptable environmental risk according to SVs, which is useful to optimise the required intervention measures.

  9. Ecological impacts of environmental toxicants and radiation on the microbial ecosystem: a model simulation of computational microbiology

    International Nuclear Information System (INIS)

    Doi, Masahiro; Sakashita, Tetsuya; Ishii, Nobuyoshi; Fuma, Shoichi; Takeda, Hiroshi; Miyamoto, Kiriko; Yanagisawa, K.; Nakamura, Yuji; Kawabata, Zenichiro

    2000-01-01

    stochasticities according to time since inoculation, and their population showed a non-linear dynamics. When SIM-COSM is stressed by environmental toxicants and radiation, it shows systematic adaptive response to a certain level. When the impacts exceeded the tolerable level, extinction risk of the ecosystem was significant. More computer-based simulation trials are left open as our future assignment. (author)

  10. Phase 2 environmental site assessment SW corner of plan 954 GV, block 7 : Main Street, Turner Valley, AB

    International Nuclear Information System (INIS)

    Reinson, E.; Harvey, K.; Brooks, N.; Burton, K.; Reinson, K.; Cropley, K.

    2010-05-01

    This document described the second phase of an environmental site assessment (ESA) at a parking lot in front of the Flare and Derrik on Main Street in Turner Valley, Alberta. The objective of this ESA was to confirm the presence of any substances of concern. The site has been occupied by an outdoor ice rink, and there is pipeline right-of-way along the east portion of the site. There is also an abandoned crude oil pipeline along the east portion of the property and an abandoned natural gas pipeline on the west side of the property. This ESA investigated the impact of the pipelines, the underground storage tanks on the adjacent sites, and the oil and gas lease on the adjacent site. Seven exploratory testholes were drilled and 3 monitoring wells were installed. The study involved soil inspection and field VOC measurements every 60 centimeters, or as required. Groundwater sampling and surveying was also performed. Groundwater and soil samples were analyzed for hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), salinity and metals. All the results for soil were below Tier 1 guidelines. There appeared to be a layer of clay fill which had some hydrocarbons, PAHs and barium present, but they were below the applicable criteria. In terms of groundwater, PAHs and selenium exceeded the Tier 1 guidelines in monitoring well no. 4 (MW4). In another well, manganese exceeded the Tier 1 guidelines. Copper exceeded the Tier 1 guidelines in all three wells. All the results were below the Tier 2 guidelines in all 3 wells with the exception of carcinogenic PAHs (B(a)P TPE) in MW4. Due to the minor presence of hydrocarbons (below criteria) located in the surficial soil layer, Ballast Environmental Consultants recommended that an environmental professional be present during the excavation and that further soil samples be taken from the suspect layer to confirm all the soils in the area of the library are below the applicable criteria. refs., tabs., figs.

  11. Phase 2 environmental site assessment SW corner of plan 954 GV, block 7 : Main Street, Turner Valley, AB

    Energy Technology Data Exchange (ETDEWEB)

    Reinson, E.; Harvey, K.; Brooks, N.; Burton, K.; Reinson, K.; Cropley, K. [Ballast Environmental Consultants Ltd., Calgary, AB (Canada)

    2010-05-15

    This document described the second phase of an environmental site assessment (ESA) at a parking lot in front of the Flare and Derrik on Main Street in Turner Valley, Alberta. The objective of this ESA was to confirm the presence of any substances of concern. The site has been occupied by an outdoor ice rink, and there is pipeline right-of-way along the east portion of the site. There is also an abandoned crude oil pipeline along the east portion of the property and an abandoned natural gas pipeline on the west side of the property. This ESA investigated the impact of the pipelines, the underground storage tanks on the adjacent sites, and the oil and gas lease on the adjacent site. Seven exploratory testholes were drilled and 3 monitoring wells were installed. The study involved soil inspection and field VOC measurements every 60 centimeters, or as required. Groundwater sampling and surveying was also performed. Groundwater and soil samples were analyzed for hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), salinity and metals. All the results for soil were below Tier 1 guidelines. There appeared to be a layer of clay fill which had some hydrocarbons, PAHs and barium present, but they were below the applicable criteria. In terms of groundwater, PAHs and selenium exceeded the Tier 1 guidelines in monitoring well no. 4 (MW4). In another well, manganese exceeded the Tier 1 guidelines. Copper exceeded the Tier 1 guidelines in all three wells. All the results were below the Tier 2 guidelines in all 3 wells with the exception of carcinogenic PAHs (B(a)P TPE) in MW4. Due to the minor presence of hydrocarbons (below criteria) located in the surficial soil layer, Ballast Environmental Consultants recommended that an environmental professional be present during the excavation and that further soil samples be taken from the suspect layer to confirm all the soils in the area of the library are below the applicable criteria. refs., tabs., figs.

  12. Transition to non-toxic gunshot use in Olympic shooting: policy implications for IOC and UNEP in resolving an environmental problem.

    Science.gov (United States)

    Thomas, Vernon George; Guitart, Raimon

    2013-10-01

    Olympic shooters discharge, annually, thousands of tons of lead shot which pose toxic risks to animals and may pollute both surface and ground waters. Non-toxic steel shot is an acceptable and effective substitute, but International Shooting Sports Federation (ISSF) rules prevent its adoption. The present policy and rules of the ISSF on lead shot use contravene the International Olympic Committee (IOC) Charter position on environmental protection. The United Nations Environment Programme (UNEP), a formal Olympic partner on environmental protection, has no stated policy on contamination from lead ammunition, despite having declared lead a Priority Area for remedial action, and is pressing to remove lead from the global human environment. The IOC Sport and Environment Commission and UNEP could examine the continued use of lead shot ammunition and advise the IOC Executive Board on appropriate changes in policy and rules that could halt the massive lead shot contamination of shooting range environments world-wide.

  13. Toxics Release Inventory (TRI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) is a dataset compiled by the U.S. Environmental Protection Agency (EPA). It contains information on the release and waste...

  14. Implementation of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Health Authority by the Agency for Toxic Substances and Disease Registry

    International Nuclear Information System (INIS)

    Siegel, M.R.

    1990-01-01

    The Superfund Amendments and Reauthorization Act (SARA) of 1986 greatly expanded the health authority of the Comprehensive Environmental Response, Compensation, and Liability Act. One of the federal agencies most affected by SARA is the Agency for Toxic Substances and Disease Registry (ATSDR) of the U.S. Public Health Service. Among other responsibilities, ATSDR was mandated to conduct health assessments within strict time frames for each site on or proposed for the U.S. Environmental Protection Agency's National Priorities List. The author will review ATSDR's efforts to address this new statutory mandate, especially for federal facilities, and will focus on different conceptual frameworks for implementing the health assessment program

  15. Effects of Environmental Contamination and Acute Toxicity of N-Nitrate on Early Life Stages of Endemic Arboreal Frog, Polypedates cruciger (Blyth, 1852).

    Science.gov (United States)

    Balangoda, Anusha; Deepananda, K H M Ashoka; Wegiriya, H C E

    2018-02-01

    This study investigated the potential toxic effects of environmentally relevant nitrate concentrations on development, growth, and mortality of early life stages of common hour-glass tree frog, Polypedates cruciger. Tadpoles from hatchlings through pre-adult were exposed to environmentally relevant nitrate concentrations detected in Mirissa, Sri Lanka. Newly hatched, external gill stage, and internal gill stage tadpoles were exposed to potassium nitrate for bioassay tests. No behavioral changes or abnormalities were observed in control and nitrate-induced group. However, detected environmental nitrate concentration significantly increased (p nitrate pollution than internal gill stage. The results suggest that environmentally relevant nitrate can cause mortality on the amphibian population in ecosystems associated with agro-pastoral activities through altering the growth and direct toxicological effects on the survivorship.

  16. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  17. Environmental pollution control through geo - botanical means - a case study of Manikpur block, Korba coalfield, M.P., India

    Energy Technology Data Exchange (ETDEWEB)

    Sikarwar, S.S.; Guha, S.; Singh, K.N. [Vikram Univ., Ujjain (India). School of Studies in Geology

    1999-09-01

    In the present paper, an environmental analysis of Manikpur area, Korba coalfield, Bilaspur, M.P., India is undertaken. The area lies in the Geological Survey of India Toposheet no. 64J/11 Latitude 82 42'54''-82 45'10'' North; Longitude 22 18'46''-22 19'46'' East. The paper deals with pollution and its control measures through the natural plants found in the vicinity of the coalmines, namely Mangifera indica, Eucalyptus spp., Cassia siamea, Delbergia sissoo, etc. The plants control the Suspended Particulate Matter (SPM), Nitrous Oxides (NOx), Sulphur Oxides (SOx) of the mines and mining site. Therefore, plantation in the mining site should be encouraged. (orig.)

  18. Estimating the gasoline components and formulations toxicity to microalgae (Tetraselmis chuii) and oyster (Crassostrea rhizophorae) embryos: An approach to minimize environmental pollution risk

    International Nuclear Information System (INIS)

    Paixao, J.F.; Nascimento, I.A.; Pereira, S.A.; Leite, M.B.L.; Carvalho, G.C.; Silveira, J.S.C.; Reboucas, M.; Matias, G.R.A.; Rodrigues, I.L.P.

    2007-01-01

    Even though petrochemical contamination frequently occurs in the form of oil spills, it is thought that a greater danger to coastal habitats is posed by chronic petrochemical toxicity associated with urban run-off, in which gasoline water-soluble-fraction (WSF) plays an important role. The hypothesis of the entrepreneurs, who were associated to the scientists uncharged of this research, was that recycled petrochemical waste may provide different gasoline formulations, having different toxic properties; the correlation between the gasoline formulations and their components' toxicological effects might contribute to the reformulation of the products, in such a way that the gasoline generated could be less toxic and less harmful to the environment. The aim of this research was to determine the toxic effects of 14 different types of gasoline (formulated, in accordance with National Petroleum Agency standards, from petrochemical waste), on Tetraselmis chuii (microalgae culture) and Crassostrea rhizophorae (embryos). Microalgae and oyster embryos were exposed to different gasoline formulations water-soluble fractions (WSF) at a range of concentrations (0%, 4.6%, 10.0%, 22.0%, 46.0%, and 100%), for 96 and 24 h, respectively. The tests were carried out under controlled conditions. End-points have been CI50-96h (concentration causing 50% growth inhibition in microalgae cultures) and EC50-24h (concentration causing abnormalities on 50% of the exposed embryos). Through these procedures, gasoline formulations, which represent the lowest environmental risk, were selected. Bioassays carried out on the 8 different gasoline components aimed to correlate gasoline toxicity with the toxic potential of its components. The analysis of principal components showed that the C9DI, a mixture of aromatic hydrocarbons of 9 carbon atoms, had the highest level of toxic potential, followed by C9S (a mixture of aromatics with 9-11 carbon atoms) and heavy naphtha. The results showed gasoline

  19. Guidelines for the disposal of dangerous and toxic wastes so as to minimize or prevent environmental and water pollution

    CSIR Research Space (South Africa)

    Rudd, RT

    1978-01-01

    Full Text Available Modern society is producing ever increasing quantities of dangerous and/or toxic wastes, which require safe and effective disposal if they are not to pose a threat to our water supplies or the environment in general....

  20. Exploratory study using proton induced X-ray emission analysis and histopathological techniques to determine the toxic burden of environmental pollutants

    International Nuclear Information System (INIS)

    Ejaz, Sohail; Ashraf, Muhammad; Shakir, Lubna; Ahmad, Nisar

    2012-01-01

    The aim of this novel research was to determine the toxic burden of increased elements in water resources on the inhabitant wild animals (squirrels, turtles, bats), using particle induced x-ray emission (PIXE) and histopathological approaches. PIXE analysis of skin, muscle, lung, liver and kidney revealed significant increase in Al, Cl, Fe, Mg, Mn, Si and V. Moreover, data clearly reflect a significant (P < 0.001) deposition of toxic elements (Al, Cl, Fe and K) in the lung producing interstitial/proliferative pneumonitis, intra-alveolar hemorrhages, and thickening of alveolar capillary walls. The results obtained from the liver samples emphasized that majority of the animals were intoxicated with Cl, Mg, S, Si and V, which have produced profound deterioration and swelling of the hepatocytes. Likewise, histopathology of the kidney sections spotlighted severe nephritis and degenerative changes, which could be associated with the elevated amount of Al, Cl and Mg. This data undoubtedly provide relevant information on the heavy burden of toxic elements and their pathological outcomes in wild animals and highlight their potential risks for human exposure. Thus, the information provided is critical for developing effective strategies in dealing with health hazards associated with elemental exposures. Highlights: ► The aim of this study was to determine environmental burden on wild animals. ► Elemental load was determined by PIXE and histological techniques. ► Lungs and liver were most affected organs. ► Environmental pollution is the main cause of different degenerative changes. - Toxic burden of environmental pollutants on wild animals

  1. Effects of Cd and Ni toxicity to Ceratophyllum demersum under environmentally relevant conditions in soft and hard water including a German lake

    Energy Technology Data Exchange (ETDEWEB)

    Andresen, Elisa, E-mail: Elisa.Andresen@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Opitz, Judith, E-mail: Daniela.Opitz@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Thomas, George, E-mail: George.Thomas@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); Stärk, Hans-Joachim, E-mail: Ha-Jo.Staerk@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, D-04318 Leipzig (Germany); Dienemann, Holger, E-mail: Holger.Dienemann@smul.sachsen.de [Saxon State Company for Environment and Agriculture, Business Domain 5 (Laboratory), Department 53, Bitterfelder Str. 25, D-04849 Bad Düben (Germany); Jenemann, Kerstin, E-mail: Kerstin.Jenemann@smul.sachsen.de [Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, Abteilung Wasser, Boden, Wertstoffe, Zur Wetterwarte 11, D-01109 Dresden (Germany); Dickinson, Bryan C., E-mail: Bryan.Dickinson@gmail.com [Harvard University, Department of Chemistry and Chemical Biology, 12 Oxford Street, Cambridge, MA 02138 (United States); Küpper, Hendrik, E-mail: Hendrik.Kuepper@uni-konstanz.de [University of Konstanz, Department of Biology, D-78457 Konstanz (Germany); University of South Bohemia, Faculty of Biological Sciences and Institute of Physical Biology, Branišovská 31, CZ-370 05 České Budejovice (Czech Republic)

    2013-10-15

    Highlights: •Hardly any macrophytic growth occurred in an oligotrophic hard water lake in Germany. •All parameters were optimal, besides elevated, nanomolar concentrations of Ni and Cd. •We cultivated submerged macrophytes in real and simulated hard and soft lake water. •Nanomolar Cd and Ni inhibited the plants’ photosynthetic light reactions in soft water. •The inhibition was synergistic, i.e. stronger than the addition of Cd and Ni effects. -- Abstract: Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant conditions like sinusoidal light and temperature cycles and a low plant biomass to water volume ratio. Experiments lasted for six weeks and were analysed by detailed measurements of photosynthetic biophysics, pigment content and hydrogen peroxide production. We established that individually non-toxic cadmium (3 nM) and slightly toxic nickel (300 nM) concentrations became highly toxic when applied together in soft water, severely inhibiting photosynthetic light reactions. Toxicity was further enhanced by phosphate limitation (75 nM) in soft water as present in many freshwater habitats. In the investigated lake, however, high water hardness limited the toxicity of these metal concentrations, thus the inhibition of macrophytic growth in the lake must have additional reasons. The results showed that synergistic heavy metal toxicity may change ecosystems in many more cases than estimated so far.

  2. Effects of Cd and Ni toxicity to Ceratophyllum demersum under environmentally relevant conditions in soft and hard water including a German lake

    International Nuclear Information System (INIS)

    Andresen, Elisa; Opitz, Judith; Thomas, George; Stärk, Hans-Joachim; Dienemann, Holger; Jenemann, Kerstin; Dickinson, Bryan C.; Küpper, Hendrik

    2013-01-01

    Highlights: •Hardly any macrophytic growth occurred in an oligotrophic hard water lake in Germany. •All parameters were optimal, besides elevated, nanomolar concentrations of Ni and Cd. •We cultivated submerged macrophytes in real and simulated hard and soft lake water. •Nanomolar Cd and Ni inhibited the plants’ photosynthetic light reactions in soft water. •The inhibition was synergistic, i.e. stronger than the addition of Cd and Ni effects. -- Abstract: Even essential trace elements are phytotoxic over a certain threshold. In this study, we investigated whether heavy metal concentrations were responsible for the nearly complete lack of submerged macrophytes in an oligotrophic lake in Germany. We cultivated the rootless aquatic model plant Ceratophyllum demersum under environmentally relevant conditions like sinusoidal light and temperature cycles and a low plant biomass to water volume ratio. Experiments lasted for six weeks and were analysed by detailed measurements of photosynthetic biophysics, pigment content and hydrogen peroxide production. We established that individually non-toxic cadmium (3 nM) and slightly toxic nickel (300 nM) concentrations became highly toxic when applied together in soft water, severely inhibiting photosynthetic light reactions. Toxicity was further enhanced by phosphate limitation (75 nM) in soft water as present in many freshwater habitats. In the investigated lake, however, high water hardness limited the toxicity of these metal concentrations, thus the inhibition of macrophytic growth in the lake must have additional reasons. The results showed that synergistic heavy metal toxicity may change ecosystems in many more cases than estimated so far

  3. Non-toxic and environmentally friendly route for preparation of copper indium sulfide based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sankir, Nurdan Demirci, E-mail: nsankir@etu.edu.tr; Aydin, Erkan; Ugur, Esma; Sankir, Mehmet

    2015-08-15

    Highlights: • Substrate structure of spray pyrolyzed CuInS{sub 2}/In{sub 2}S{sub 3} heterojunction solar cells. • Low cost and environmentally friendly fabrication of CuInS{sub 2} based solar cells. • Low RF power deposition of TCO layer. • AZO–Ag–AZO sandwich structure. • Effect of the thickness of buffer layer on the photovoltaic performance. - Abstract: In this study, copper based thin film solar cells with substrate structure have been built via spray pyrolysis method. Toxic material usage was avoided during the material deposition and the post-treatment steps. Novel device configuration of Mo/CuInS{sub 2}/In{sub 2}S{sub 3}/ZnO/AZO–Ag–AZO was studied as a function of the In{sub 2}S{sub 3} buffer layer thickness. In order to utilize the zinc oxide (ZnO) and aluminum doped zinc oxide (AZO) transparent conductive layers, deposited by physical vapor deposition (PVD), on top of the spray pyrolyzed thin films, the RF power was lowered to 30 W. Although this minimized the unwanted penetration of the highly energetic particles, created during PVD process, sheet resistivity of the AZO films increased enormously. Hence very thin silver layer has been deposited between two AZO films. This resulted the decrease in the sheet resistivity more than 10{sup 6} times. Electrical measurements under illumination revealed that short circuit current density (J{sub sc}), open circuit voltage (V{sub oc}), fill factor (FF) and efficiency (η) of the Mo/CuInS{sub 2}/In{sub 2}S{sub 3}/ZnO/AZO–Ag–AZO type solar cells increased with increasing the thickness of the In{sub 2}S{sub 3} layer. The maximum J{sub sc} of 9.20 mA/cm{sup 2}, V{sub oc} of 0.43 V, FF of 0.44 have been observed for the 0.94 μm-thick In{sub 2}S{sub 3} layer. Extraordinarily thick buffer layer provided better diffusion barrier between the absorber and the TCO layers and also resulted better photosensitivity. These could be the key factors to produce substrate configuration of the spray pyrolyzed

  4. The toxicity of cationic surfactant HDTMA-Br, desorbed from surfactant modified zeolite, towards faecal indicator and environmental microorganisms.

    Science.gov (United States)

    Reeve, Peter J; Fallowfield, Howard J

    2017-10-05

    Surfactant Modified Zeolite (SMZ) represents a versatile, cost-effective permeable reactive material, capable of treating multiple classes of contaminants. The potential for HDTMA-Br, a cationic surfactant commonly used to modify zeolite, to desorb from the zeolite surface has been identified as a potential issue for the ongoing use of SMZ in water remediation contexts. This paper investigates the toxicity of HDTMA-Br towards enteric virus surrogates, F-RNA bacteriophage MS2 and E. coli, Bacillus subtilis, and soil microflora. The concentration of surfactant desorbing from SMZ was quantified through a bioassay using E. coli. Results showed HDTMA-Br concentrations of ≥10 -5 M were toxic to MS2, ≥10 -4 M were toxic to E. coli and ≥10 -6 M were toxic to B. subtilis. No toxic relationship was established between HDTMA-Br and soil microflora. Desorption of ≥10 -4 M of HDTMA-Br was shown for the two SMZ samples under the mixing conditions used. Effects of this surfactant on total soil microflora were ambiguous since no toxic relationship could be established, however, HDTMA-Br, at concentrations desorbing from SMZ, were shown to impact the soil bacterium B. subtilis. Further research is required to determine the effect of this surfactant on microbial populations and species diversity in soils. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Marine toxic substance and other data from the Gulf of Alaska from the MOANA WAVE as part of the Outer Continental Shelf Environmental Assessment Program from 1976-06-25 to 078 July 1976 (NCEI Accession 7601849)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine toxic substance and other data were collected in the Gulf of Alaska from the MOANA WAVE. Data were collected by Pacific Marine Environmental Laboratory (PMEL)...

  6. Linking high resolution mass spectrometry data with exposure and toxicity forecasts to advance high-throughput environmental monitoring

    Data.gov (United States)

    U.S. Environmental Protection Agency — There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and...

  7. COMPUTER-BASED PREDICTION OF TOXICITY USING THE ELECTRON-CONFORMATIONAL METHOD. APPLICATION TO FRAGRANCE ALLERGENS AND OTHER ENVIRONMENTAL POLLUTANTS

    Directory of Open Access Journals (Sweden)

    Natalia N. Gorinchoy

    2012-06-01

    Full Text Available The electron-conformational (EC method is employed for the toxicophore (Tph identification and quantitative prediction of toxicity using the training set of 24 compounds that are considered as fragrance allergens. The values of a=LD50 in oral exposure of rats were chosen as a measure of toxicity. EC parameters are evaluated on the base of conformational analysis and ab initio electronic structure calculations (including solvent influence. The Tph consists of four sites which in this series of compounds are represented by three carbon and one oxygen atoms, but may be any other atoms that have the same electronic and geometric features within the tolerance limits. The regression model taking into consideration the Tph flexibility, anti-Tph shielding, and influence of out-of-Tph functional groups predicts well the experimental values of toxicity (R2 = 0.93 with a reasonable leaveone- out cross-validation.

  8. Keratinocyte-derived IL-24 plays a role in the positive feedback regulation of epidermal inflammation in response to environmental and endogenous toxic stressors.

    Science.gov (United States)

    Jin, Sun Hee; Choi, Dalwoong; Chun, Young-Jin; Noh, Minsoo

    2014-10-15

    Keratinocytes are the major cellular components of human epidermis and play a key role in the modulating cutaneous inflammation and toxic responses. In human chronic skin diseases, the common skin inflammatory phenotypes like skin barrier disruption and epidermal hyperplasia are manifested in epidermal keratinocytes by interactions with T helper (Th) cells. To find a common gene expression signature of human keratinocytes in chronic skin diseases, we performed a whole genome microarray analysis on normal human epidermal keratinocytes (NHKs) treated with IFNγ, IL-4, IL-17A or IL-22, major cytokines from Th1, Th2, Th17 or Th22 cells, respectively. The microarray results showed that the four genes, IL-24, PDZK1IP1, H19 and filaggrin, had common expression profiles in NHKs exposed to Th cell cytokines. In addition, the acute phase pro-inflammatory cytokines, IL-1β, IL-6 and TNFα, also change the gene transcriptional profile of IL-24, PDZK1IP1, H19, and filaggrin in NHKs as those of Th cytokines. Therefore, the signature gene set, consisting of IL-24, PDZK1IP1, H19, and filaggrin, provides essential insights for understanding the process of cutaneous inflammation and toxic responses. We demonstrate that environmental toxic stressors, such as chemical irritants and ultraviolet irradiation stimulate the production of IL-24 in NHKs. IL-24 stimulates the JAK1-STAT3 and MAPK pathways in NHKs, and promotes the secretion of pro-inflammatory mediators IL-8, PGE2, and MMP-1. These results suggest that keratinocyte-derived IL-24 participates in the positive feedback regulation of epidermal inflammation in response to both endogenous and environmental toxic stressors. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, Jos; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In

  10. Keratinocyte-derived IL-24 plays a role in the positive feedback regulation of epidermal inflammation in response to environmental and endogenous toxic stressors

    International Nuclear Information System (INIS)

    Jin, Sun Hee; Choi, Dalwoong; Chun, Young-Jin; Noh, Minsoo

    2014-01-01

    Keratinocytes are the major cellular components of human epidermis and play a key role in the modulating cutaneous inflammation and toxic responses. In human chronic skin diseases, the common skin inflammatory phenotypes like skin barrier disruption and epidermal hyperplasia are manifested in epidermal keratinocytes by interactions with T helper (Th) cells. To find a common gene expression signature of human keratinocytes in chronic skin diseases, we performed a whole genome microarray analysis on normal human epidermal keratinocytes (NHKs) treated with IFNγ, IL-4, IL-17A or IL-22, major cytokines from Th1, Th2, Th17 or Th22 cells, respectively. The microarray results showed that the four genes, IL-24, PDZK1IP1, H19 and filaggrin, had common expression profiles in NHKs exposed to Th cell cytokines. In addition, the acute phase pro-inflammatory cytokines, IL-1β, IL-6 and TNFα, also change the gene transcriptional profile of IL-24, PDZK1IP1, H19, and filaggrin in NHKs as those of Th cytokines. Therefore, the signature gene set, consisting of IL-24, PDZK1IP1, H19, and filaggrin, provides essential insights for understanding the process of cutaneous inflammation and toxic responses. We demonstrate that environmental toxic stressors, such as chemical irritants and ultraviolet irradiation stimulate the production of IL-24 in NHKs. IL-24 stimulates the JAK1-STAT3 and MAPK pathways in NHKs, and promotes the secretion of pro-inflammatory mediators IL-8, PGE2, and MMP-1. These results suggest that keratinocyte-derived IL-24 participates in the positive feedback regulation of epidermal inflammation in response to both endogenous and environmental toxic stressors. - Highlights: • Cutaneous inflammatory gene signature consists of PDZK1IP1, IL-24, H19 and filaggrin. • Pro-inflammatory cytokines increase IL-24 production in human keratinocytes. • Environmental toxic stressors increase IL-24 production in human keratinocytes. • IL-24 stimulates human keratinocytes to

  11. Keratinocyte-derived IL-24 plays a role in the positive feedback regulation of epidermal inflammation in response to environmental and endogenous toxic stressors

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Sun Hee [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 151-742 (Korea, Republic of); Choi, Dalwoong [Department of Public Health Science, Korea University, Seoul 136-701 (Korea, Republic of); Chun, Young-Jin [College of Pharmacy, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Noh, Minsoo, E-mail: minsoo@alum.mit.edu [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2014-10-15

    Keratinocytes are the major cellular components of human epidermis and play a key role in the modulating cutaneous inflammation and toxic responses. In human chronic skin diseases, the common skin inflammatory phenotypes like skin barrier disruption and epidermal hyperplasia are manifested in epidermal keratinocytes by interactions with T helper (Th) cells. To find a common gene expression signature of human keratinocytes in chronic skin diseases, we performed a whole genome microarray analysis on normal human epidermal keratinocytes (NHKs) treated with IFNγ, IL-4, IL-17A or IL-22, major cytokines from Th1, Th2, Th17 or Th22 cells, respectively. The microarray results showed that the four genes, IL-24, PDZK1IP1, H19 and filaggrin, had common expression profiles in NHKs exposed to Th cell cytokines. In addition, the acute phase pro-inflammatory cytokines, IL-1β, IL-6 and TNFα, also change the gene transcriptional profile of IL-24, PDZK1IP1, H19, and filaggrin in NHKs as those of Th cytokines. Therefore, the signature gene set, consisting of IL-24, PDZK1IP1, H19, and filaggrin, provides essential insights for understanding the process of cutaneous inflammation and toxic responses. We demonstrate that environmental toxic stressors, such as chemical irritants and ultraviolet irradiation stimulate the production of IL-24 in NHKs. IL-24 stimulates the JAK1-STAT3 and MAPK pathways in NHKs, and promotes the secretion of pro-inflammatory mediators IL-8, PGE2, and MMP-1. These results suggest that keratinocyte-derived IL-24 participates in the positive feedback regulation of epidermal inflammation in response to both endogenous and environmental toxic stressors. - Highlights: • Cutaneous inflammatory gene signature consists of PDZK1IP1, IL-24, H19 and filaggrin. • Pro-inflammatory cytokines increase IL-24 production in human keratinocytes. • Environmental toxic stressors increase IL-24 production in human keratinocytes. • IL-24 stimulates human keratinocytes to

  12. Detection block

    International Nuclear Information System (INIS)

    Bezak, A.

    1987-01-01

    A diagram is given of a detection block used for monitoring burnup of nuclear reactor fuel. A shielding block is an important part of the detection block. It stabilizes the fuel assembly in the fixing hole in front of a collimator where a suitable gamma beam is defined for gamma spectrometry determination of fuel burnup. The detector case and a neutron source case are placed on opposite sides of the fixing hole. For neutron measurement for which the water in the tank is used as a moderator, the neutron detector-fuel assembly configuration is selected such that neutrons from spontaneous fission and neutrons induced with the neutron source can both be measured. The patented design of the detection block permits longitudinal travel and rotation of the fuel assembly to any position, and thus more reliable determination of nuclear fuel burnup. (E.S.). 1 fig

  13. Does the recommended lymphocyte cytokinesis-block micronucleus assay for human biomonitoring actually detect DNA damage induced by occupational and environmental exposure to genotoxic chemicals?

    Science.gov (United States)

    Speit, Günter

    2013-07-01

    This commentary challenges the paradigm that the cytokinesis-block micronucleus assay (CBMN assay) with cultured human lymphocytes, as it is performed currently, is a sensitive and useful tool for detecting genotoxic effects in populations exposed occupationally or environmentally to genotoxic chemicals. Based on the principle of the assay and the available data, increased micronucleus (MN) frequencies in binucleated cells (BNC) are mainly due to MN produced in vitro during the cultivation period (i.e. MN produced in vivo do not substantially contribute to the MN frequency measured in BNC). The sensitivity of the assay for the detection of induced MN in BNC after an in vivo exposure to a genotoxic chemical is limited because cytochalasin B (Cyt-B) is added relatively late during the culture period and, therefore, the BNC that are scored do not always represent cells that have completed one cell cycle only. Furthermore, this delay means that damaged cells can be eliminated by apoptosis and/or that DNA damage induced in vivo can be repaired prior to the production of a MN in the presence of Cyt-B. A comparison with the in vitro CBMN assay used for genotoxicity testing leads to the conclusion that it is highly unlikely that DNA damage induced in vivo is the cause for increased MN frequencies in BNC after occupational or environmental exposure to genotoxic chemicals. This commentary casts doubt on the usefulness of the CBMN assay as an indicator of genotoxicity in human biomonitoring and questions the relevance of many published data for hazard identification and risk assessment. Thus, it seems worthwhile to reconsider the use of the CBMN assay as presently conducted for the detection of genotoxic exposure in human biomonitoring.

  14. Mercapturic acids: recent advances in their determination by liquid chromatography/mass spectrometry and their use in toxicant metabolism studies and in occupational and environmental exposure studies

    Science.gov (United States)

    Mathias, Patricia I.; B’Hymer, Clayton

    2016-01-01

    This review describes recent selected HPLC/MS methods for the determination of urinary mercapturates that are useful as non-invasive biomarkers in characterizing human exposure to electrophilic industrial chemicals in occupational and environmental studies. High performance liquid chromatography/mass spectrometry is a sensitive and specific method for analysis of small molecules found in biological fluids. In this review, recent selected mercapturate quantification methods are summarized and specific cases are presented. The biological formation of mercapturates is introduced and their use indicators of metabolic processing of reactive toxicants is discussed, as well as future trends and limitations in this area of research. PMID:26900903

  15. Toxicity and disruption of quorum sensing in Aliivibrio fisheri by environmental chemicals: Impacts of selected contaminants and microplastics

    Directory of Open Access Journals (Sweden)

    François Gagné

    2017-11-01

    Full Text Available The purpose of this study was to examine the effects of dissolved and particulate compounds on quorum sensing in the marine luminescent bacterium Aliivibrio fisheri. Bacteria were exposed to increasing concentrations of CuSO4 (Cu2+, gadolinium chloride (Gd3+, 20-nm silver nanoparticles (nanoAg and 1-3 μm microplastic polyethylene beads for 250 min. During this period, luminescence measurements were taken at 5-min intervals. Toxicity was first examined by measuring luminescence output at 5-min and 30-min incubation time. Based on the effective concentration that decreases luminescence by 20% (EC20, the compounds were toxic at the following concentrations in decreasing toxicity: Cu2+ (3.2 mg/L < nanoAg (3.4 mg/L, reported < Gd3+ (34 mg/L < microplastics (2.6 g/L. The data revealed that luminescence changed non-linearly over time. In control bacteria, luminescence changed at eight specific major frequencies between 0.04 and 0.27 cycle/min after Fourier transformation of time-dependent luminescence data. The addition of dissolved Cu2+ and Gd3+ eliminated the amplitude changes at these frequencies in a concentration-dependent manner, indicating loss of quorum sensing between bacteria at concentrations below EC20. In the presence of nanoAg and microplastic beads, the decreases in amplitudes were modest but compressed the luminescence profiles, with shorter frequencies appearing at concentrations well below EC20. Thus, loss of communication between bacteria occurs at non-toxic concentrations. In addition, with exposure to a mixture of the above compounds at concentrations that do not produce effects for Gd3+, nanoAg and microplastics, Cu2+ toxicity was significantly enhanced, suggesting synergy. This study revealed for the first time that small microplastic particles and nanoparticles can disrupt quorum sensing in marine bacteria.

  16. National Air Toxic Assessments (NATA) Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Air Toxics Assessment was conducted by EPA in 2002 to assess air toxics emissions in order to identify and prioritize air toxics, emission source types...

  17. Effects of nanomolar copper on water plants—Comparison of biochemical and biophysical mechanisms of deficiency and sublethal toxicity under environmentally relevant conditions

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, George, E-mail: george.thomas@uni.kn [Universität Konstanz, Mathematisch-Naturwissenschaftliche Sektion, Fachbereich Biologie, D-78457 Konstanz (Germany); Stärk, Hans-Joachim, E-mail: ha-jo.staerk@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstr. 15, D-04318 Leipzig (Germany); Wellenreuther, Gerd, E-mail: Gerd.wellenreuther@desy.de [HASYLAB at DESY, Notkestr. 85, 22603 Hamburg (Germany); Dickinson, Bryan C., E-mail: bryan.dickinson@gmail.com [Harvard University, Department of Chemistry and Chemical Biology, 12 Oxford Street, Cambridge, MA 02138 (United States); Küpper, Hendrik, E-mail: hendrik.kuepper@uni-konstanz.de [Universität Konstanz, Mathematisch-Naturwissenschaftliche Sektion, Fachbereich Biologie, D-78457 Konstanz (Germany); University of South Bohemia, Faculty of Biological Sciences and Institute of Physical Biology, Branišovská 31, CZ-370 05 České Budejovice (Czech Republic)

    2013-09-15

    Highlights: •We found different optimal Cu requirement for different physiological mechanisms. •Kinetics and concentration thresholds of damage mechanisms were established. •Cu toxicity caused internal Cu re-distribution and inhibition of Zn uptake. •Cu deficient plants released Cu, indicating lack of high-affinity Cu transporters. •Cu deficiency caused re-distribution of zinc in the plant. -- Abstract: Toxicity and deficiency of essential trace elements like Cu are major global problems. Here, environmentally relevant sub-micromolar concentrations of Cu (supplied as CuSO{sub 4}) and simulations of natural light- and temperature cycles were applied to the aquatic macrophyte Ceratophyllum demersum. Growth was optimal at 10 nM Cu, while PSII activity (F{sub v}/F{sub m}) was maximal around 2 nM Cu. Damage to the PSII reaction centre was the first target of Cu toxicity, followed by disturbed regulation of heat dissipation (NPQ). Only after that, electron transport through PSII (Φ{sub PSII}) was inhibited, and finally chlorophylls decreased. Copper accumulation in the plants was stable until 10 nM Cu in solution, but strongly increased at higher concentrations. The vein was the main storage site for Cu up to physiological concentrations (10 nM). At toxic levels it was also sequestered to the epidermis and mesophyll until export from the vein became inhibited, accompanied by inhibition of Zn uptake. Copper deficiency led to a complete stop of growth at “0” nM Cu after 6 weeks. This was accompanied by high starch accumulation although electron flow through PSII (Φ{sub PSII}) decreased from 2 weeks, followed by decrease in pigments and increase of non photochemical quenching (NPQ). Release of Cu from the plants below 10 nM Cu supply in the nutrient solution indicated lack of high-affinity Cu transporters, and on the tissue level copper deficiency led to a re-distribution of zinc.

  18. Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

    KAUST Repository

    Almuslem, A. S.; Hanna, Amir; Yapici, Tahir; Wehbe, N.; Diallo, Elhadj; Kutbee, Arwa T.; Bahabry, Rabab R.; Hussain, Muhammad Mustafa

    2017-01-01

    , in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured

  19. Reproductive toxicity parameters and biological monitoring in occupationally and environmentally boron-exposed persons in Bandirma, Turkey.

    Science.gov (United States)

    Duydu, Yalçın; Başaran, Nurşen; Üstündağ, Aylin; Aydin, Sevtap; Ündeğer, Ülkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçın; Ickstadt, Katja; Waltrup, Britta Schulze; Golka, Klaus; Bolt, Hermann M

    2011-06-01

    Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. Experimentally, a NOAEL (no observed adverse effect level) of 17.5 mg B/kg-bw/day has been identified for the (male) reproductive effects of boron in a multigeneration study of rats, and a NOAEL for the developmental effects in rats was identified at 9.6 mg B/kg-bw/day. These values are being taken as the basis of current EU safety assessments. The present study was conducted to investigate the reproductive effects of boron exposure in workers employed in boric acid production plant in Bandirma, Turkey. In order to characterize the external and internal boron exposures, boron was determined in biological samples (blood, urine, semen), in workplace air, in food, and in water sources. Unfavorable effects of boron exposure on the reproductive toxicity indicators (concentration, motility, morphology of the sperm cells and blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone) were not observed. The mean calculated daily boron exposure (DBE) of the highly exposed group was 14.45 ± 6.57 (3.32-35.62) mg/day. These human exposures represent worst-case exposure conditions to boric acid/borates in Turkey. These exposure levels are considerably lower than exposures, which have previously led to reproductive effects in experimental animals. In conclusion, this means that dose levels of boron associated with developmental and reproductive toxic effects in animals are by far not reachable for humans under conditions of normal handling and use.

  20. Implications in studies of environmental risk assessments: Does culture medium influence the results of toxicity tests of marine bacteria?

    Science.gov (United States)

    Díaz-García, Alejandra; Borrero-Santiago, Ana R; Riba, Inmaculada

    2018-04-14

    Two marine bacterial populations (Roseobacter sp. and Pseudomonas litoralis) were exposed to different concentrations of zinc (300, 625, 1250, 2000, 2500 and 5000 mg L -1 ) and cadmium (75, 250, 340, 500 and 1000 mg L -1 ) using two culture media (full nutrient Marine Broth 2216 "MB" and 1:10 (vol/vol) dilution with seawater of Marine Broth 2216 "MB SW "), in order to assess population responses depending on the culture medium and also potential adverse effects associated with these two metals. Different responses were found depending on the culture medium (Bacterial abundance (cells·mL -1 ), growth rates (μ, hours -1 ), and production of Extracellular Polysaccharides Substances (EPS) (μg glucose·cells -1 ). Results showed negative effects in both strains after the exposure to Zn treatments. Both strains showed highest metal sensitivity at low concentrations using both culture media. However, different results were found when exposing the bacterial populations to Cd treatments depending on the culture medium. Highest toxicity was observed using MB at low levels of Cd concentrations, whereas MB SW showed toxicity to bacteria at higher concentrations of Cd. Results not only showed adverse effects on Roseobacter sp. and Pseudomonas litoralis associated with the concentration of Zn and Cd, but also confirm that depending on the culture medium results can differ. This work suggests MB SW as an adequate culture medium to study metal toxicity bioassays in order to predict realistic effects on marine bacterial populations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Toxicity Reference Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxicity Reference Database (ToxRefDB) contains approximately 30 years and $2 billion worth of animal studies. ToxRefDB allows scientists and the interested...

  2. Recent Trends in Rapid Environmental Monitoring of Pathogens and Toxicants: Potential of Nanoparticle-Based Biosensor and Applications

    Science.gov (United States)

    Koedrith, Preeyaporn; Thasiphu, Thalisa; Weon, Jong-Il; Boonprasert, Rattana; Tuitemwong, Kooranee; Tuitemwong, Pravate

    2015-01-01

    Of global concern, environmental pollution adversely affects human health and socioeconomic development. The presence of environmental contaminants, especially bacterial, viral, and parasitic pathogens and their toxins as well as chemical substances, poses serious public health concerns. Nanoparticle-based biosensors are considered as potential tools for rapid, specific, and highly sensitive detection of the analyte of interest (both biotic and abiotic contaminants). In particular, there are several limitations of conventional detection methods for water-borne pathogens due to low concentrations and interference with various enzymatic inhibitors in the environmental samples. The increase of cells to detection levels requires long incubation time. This review describes current state of biosensor nanotechnology, the advantage over conventional detection methods, and the challenges due to testing of environmental samples. The major approach is to use nanoparticles as signal reporter to increase output rather than spending time to increase cell concentrations. Trends in future development of novel detection devices and their advantages over other environmental monitoring methodologies are also discussed. PMID:25884032

  3. Toxic effect of chemicals dumped in premises of UCIL, Bhopal leading to environmental pollution: An in silico approach

    Directory of Open Access Journals (Sweden)

    Manish Kumar Tripathi

    2016-04-01

    Full Text Available Objective: To investigate the role of dumped residues in the loss of immunity using human immune proteins, which provides protection against Mycobacterium tuberculosis. Methods: In this study, toxic chemicals were docked with immune proteins using AutoDock 4.0, and further, molecular dynamics simulations were performed for refinement of the docked complexes which were obtained from docking to confirm its stable behaviour over the entire simulation period. Results: Results revealed that alpha-naphthol showed the maximum inhibition with glutathione synthetase protein, while butylated hydroxytoluene and carbaryl showed the maximum inhibition with p38 MAPK14 protein with binding free energy ΔG -5.06, -5.1 and -5.36 kcal/ mol, respectively. Molecular dynamics simulation supported the greater stability of carbaryl and alpha-naphthol complexes with p38 MAPK 14 and glutathione synthetase protein as compared to butylated hydroxytoluene. Conclusions: In summary, findings suggested that toxic exposure of carbaryl and alphanaphthol as compared to butylated hydroxytoluene generated immunotoxicity and disrupted the functioning of immune system thus it may have caused an increase in susceptibility to Mycobacterium tuberculosis infection.

  4. Amperometric screen-printed algal biosensor with flow injection analysis system for detection of environmental toxic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shitanda, Isao [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)], E-mail: shitanda@rs.noda.tus.ac.jp; Takamatsu, Satoshi; Watanabe, Kunihiro; Itagaki, Masayuki [Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2009-08-30

    A screen-printed algal biosensor was fabricated for evaluation of toxicity of chemicals. An algal ink was prepared by mixing unicellular microalga Chlorella vulgaris cells, carbon nanotubes and sodium alginate solution. The algal ink was immobilized directly on a screen-printed carbon electrode surface using screen-printing technique. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU) were evaluated as inhibition ratios of the reduction current. The concentrations that gave 50% inhibition of the oxygen reduction current (IC{sup '}{sub 50}) for atrazine and DCMU were 12 and 1 {mu}mol dm{sup -3}, respectively. In comparison with the conventional algal biosensors, in which the algal cells were entrapped in an alginate gel and immobilized on the surface of a transparent indium tin oxide electrode, the present sensor is much smaller and less expensive, with the shorter assay time.

  5. Amperometric screen-printed algal biosensor with flow injection analysis system for detection of environmental toxic compounds

    International Nuclear Information System (INIS)

    Shitanda, Isao; Takamatsu, Satoshi; Watanabe, Kunihiro; Itagaki, Masayuki

    2009-01-01

    A screen-printed algal biosensor was fabricated for evaluation of toxicity of chemicals. An algal ink was prepared by mixing unicellular microalga Chlorella vulgaris cells, carbon nanotubes and sodium alginate solution. The algal ink was immobilized directly on a screen-printed carbon electrode surface using screen-printing technique. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to four toxic compounds, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4-diamine (atrazine) and 3-(3,4-dichlorophenyl)-1,1-diethylurea (DCMU) were evaluated as inhibition ratios of the reduction current. The concentrations that gave 50% inhibition of the oxygen reduction current (IC ' 50 ) for atrazine and DCMU were 12 and 1 μmol dm -3 , respectively. In comparison with the conventional algal biosensors, in which the algal cells were entrapped in an alginate gel and immobilized on the surface of a transparent indium tin oxide electrode, the present sensor is much smaller and less expensive, with the shorter assay time.

  6. Local anaesthetic toxicity

    African Journals Online (AJOL)

    Local anaesthetic toxicity has been known since the introduction of local anaesthetic drugs into anaesthetic practice more than a hundred ... was the first to think of cocaine as a narcotic. ..... anaesthetics act as Na+ channel-blocking agents, they slow down .... all neurons, leading to global CNS depression, slowing and.

  7. Assessing the environmental hazard of individual and combined pharmaceuticals: acute and chronic toxicity of fluoxetine and propranolol in the crustacean Daphnia magna.

    Science.gov (United States)

    Varano, Valentina; Fabbri, Elena; Pasteris, Andrea

    2017-08-01

    Pharmaceuticals are widespread emerging contaminants and, like all pollutants, are present in combination with others in the ecosystems. The aim of the present work was to evaluate the toxic response of the crustacean Daphnia magna exposed to individual and combined pharmaceuticals. Fluoxetine, a selective serotonin re-uptake inhibitor widely prescribed as antidepressant, and propranolol, a non-selective β-adrenergic receptor-blocking agent used to treat hypertension, were tested. Several experimental trials of an acute immobilization test and a chronic reproduction test were performed. Single chemicals were first tested separately. Toxicity of binary mixtures was then assessed using a fixed ratio experimental design. Five concentrations and 5 percentages of each substance in the mixture (0, 25, 50, 75, and 100%) were tested. The MIXTOX model was applied to analyze the experimental results. This tool is a stepwise statistical procedure that evaluates if and how observed data deviate from a reference model, either concentration addition (CA) or independent action (IA), and provides significance testing for synergism, antagonism, or more complex interactions. Acute EC50 values ranged from 6.4 to 7.8 mg/L for propranolol and from 6.4 to 9.1 mg/L for fluoxetine. Chronic EC50 values ranged from 0.59 to 1.00 mg/L for propranolol and from 0.23 to 0.24 mg/L for fluoxetine. Results showed a significant antagonism between chemicals in both the acute and the chronic mixture tests when CA was adopted as the reference model, while absence of interactive effects when IA was used.

  8. Environmental toxicants cause sperm DNA fragmentation as detected by the Sperm Chromatin Structure Assay (SCSA[reg])

    International Nuclear Information System (INIS)

    Evenson, Donald P.; Wixon, Regina

    2005-01-01

    Studies over the past two decades have clearly shown that reproductive toxicants cause sperm DNA fragmentation. This DNA fragmentation can usually be detected prior to observing alterations of metaphase chromosomes in embryos. Thus, Sperm Chromatin Structure Assay (SCSA)-detected DNA damage is viewed as the molecular precursor to later gross chromosome damage observed under the light microscope. SCSA measurements of animal or human sperm consist of first obtaining a fresh or flash frozen neat semen sample in LN2 or dry ice. Samples are then sent to a SCSA diagnostic laboratory where the samples are thawed, diluted to ∼1-2 x 106 sperm/ml, treated for 30 s with a pH 1.2 detergent buffer and then stained with acridine orange (AO). The low pH partially denatures DNA at the sites of DNA strand breaks and the AO-ssDNA fluoresces red while the AO-dsDNA fluoresces green. Flow cytometry measurements of 5000 sperm/sample provide statistically robust data on the ratio of red to green sperm, the extent of the DNA fragmentation and the standard deviations of measures. Numerous experiments on rodents treated with reproductive toxicants clearly showed that SCSA measures are highly dose responsive and have a very low CV. Different agents that act on germ cells at various stages of development usually showed sperm DNA fragmentation when that germ cell fraction arrived in the epididymis or ejaculate. Some of these treated samples were capable of successful in vitro fertilization but with frequent embryo failure. A 2-year longitudinal study of men living a valley town with a reported abnormal level of infertility and spontaneous miscarriages and also a seasonal atmospheric smog pollution, showed, for the first time, that SCSA measurements of human sperm DNA fragmentation were detectable and correlated with dosage of air pollution while the classical semen measures were not correlated. Also, young men spraying pesticides without protective gear are at an increased risk for elevated

  9. Cultivation of the heart urchin Echinocardium cordatum and validation of its use in marine toxicity testing for environmental risk assessment

    NARCIS (Netherlands)

    Schipper, C.A.; Dubbeldam, M.; Feist, S.W.; Rietjens, I.M.C.M.; Murk, A.J.

    2008-01-01

    To study environmental risk assessment, echinoderms provide a useful model for ecotoxicological testing. However, limited knowledge of the life history of field collected heart urchins is a problem and the use of cultured urchins has been investigated here. The present study describes a culture

  10. Environmental Exposure of Children to Toxic Trace Elements (Hg, Cr, As) in an Urban Area of Yucatan, Mexico: Water, Blood, and Urine Levels.

    Science.gov (United States)

    Arcega-Cabrera, F; Fargher, L; Quesadas-Rojas, M; Moo-Puc, R; Oceguera-Vargas, I; Noreña-Barroso, E; Yáñez-Estrada, L; Alvarado, J; González, L; Pérez-Herrera, N; Pérez-Medina, S

    2018-05-01

    Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.

  11. Water soluble nano-scale transient material germanium oxide for zero toxic waste based environmentally benign nano-manufacturing

    KAUST Repository

    Almuslem, A. S.

    2017-02-14

    In the recent past, with the advent of transient electronics for mostly implantable and secured electronic applications, the whole field effect transistor structure has been dissolved in a variety of chemicals. Here, we show simple water soluble nano-scale (sub-10 nm) germanium oxide (GeO) as the dissolvable component to remove the functional structures of metal oxide semiconductor devices and then reuse the expensive germanium substrate again for functional device fabrication. This way, in addition to transiency, we also show an environmentally friendly manufacturing process for a complementary metal oxide semiconductor (CMOS) technology. Every year, trillions of complementary metal oxide semiconductor (CMOS) electronics are manufactured and billions are disposed, which extend the harmful impact to our environment. Therefore, this is a key study to show a pragmatic approach for water soluble high performance electronics for environmentally friendly manufacturing and bioresorbable electronic applications.

  12. In vitro profiling of toxic effects of prominent environmental lower-chlorinated PCB congeners linked with endocrine disruption and tumor promotion.

    Science.gov (United States)

    Pěnčíková, Kateřina; Svržková, Lucie; Strapáčová, Simona; Neča, Jiří; Bartoňková, Iveta; Dvořák, Zdeněk; Hýžďalová, Martina; Pivnička, Jakub; Pálková, Lenka; Lehmler, Hans-Joachim; Li, Xueshu; Vondráček, Jan; Machala, Miroslav

    2018-06-01

    The mechanisms contributing to toxic effects of airborne lower-chlorinated PCB congeners (LC-PCBs) remain poorly characterized. We evaluated in vitro toxicities of environmental LC-PCBs found in both indoor and outdoor air (PCB 4, 8, 11, 18, 28 and 31), and selected hydroxylated metabolites of PCB 8, 11 and 18, using reporter gene assays, as well as other functional cellular bioassays. We focused on processes linked with endocrine disruption, tumor promotion and/or regulation of transcription factors controlling metabolism of both endogenous compounds and xenobiotics. The tested LC-PCBs were found to be mostly efficient anti-androgenic (within nanomolar - micromolar range) and estrogenic (at micromolar concentrations) compounds, as well as inhibitors of gap junctional intercellular communication (GJIC) at micromolar concentrations. PCB 8, 28 and 31 were found to partially inhibit the aryl hydrocarbon receptor (AhR)-mediated activity. The tested LC-PCBs were also partial constitutive androstane receptor (CAR) and pregnane X receptor (PXR) agonists, with PCB 4, 8 and 18 being the most active compounds. They were inactive towards other nuclear receptors, such as vitamin D receptor, thyroid receptor α, glucocorticoid receptor or peroxisome proliferator-activated receptor γ. We found that only PCB 8 contributed to generation of oxidative stress, while all tested LC-PCBs induced arachidonic acid release (albeit without further modulations of arachidonic acid metabolism) in human lung epithelial cells. Importantly, estrogenic effects of hydroxylated (OH-PCB) metabolites of LC-PCBs (4-OH-PCB 8, 4-OH-PCB 11 and 4'-OH-PCB 18) were higher than those of the parent PCBs, while their other toxic effects were only slightly altered or suppressed. This suggested that metabolism may alter toxicity profiles of LC-PCBs in a receptor-specific manner. In summary, anti-androgenic and estrogenic activities, acute inhibition of GJIC and suppression of the AhR-mediated activity were

  13. Bio- and toxic elements in edible wild mushrooms from two regions of potentially different environmental conditions in eastern Poland.

    Science.gov (United States)

    Brzezicha-Cirocka, Justyna; Mędyk, Małgorzata; Falandysz, Jerzy; Szefer, Piotr

    2016-11-01

    In the present study, the composition of bio-elements (K, Na, Mg, Ca, Fe, Cu, Zn) and toxic elements (Ag, Cd) in seven edible mushrooms from the rural and woodland region of Morąg (north-eastern Poland) and the rural and industrial region of the Tarnobrzeska Upland (south-eastern Poland) were investigated using a validated method. The species examined were Boletus edulis, Cantharellus cibarius, Leccinum aurantiacum, Leccinum versipelle, Lycoperdon perlatum, Suillus luteus, and Xerocomus subtomentosus. Final determination was carried out by flame atomic absorption spectroscopy (FAAS) after microwave-assisted decomposition of sample matrices with solutions of concentrated nitric acid in the pressurized polytetrafluoroethylene vessels. The contents of the alkali elements and alkali earth elements were determined in the species surveyed. The alkali elements, earth alkali elements, and transition metals (Ag, Cu, Zn, Fe, and Mn) were at typical concentrations as was determined for the same or similar species elsewhere in Poland and Europe. The results may suggest a lack of local and regional emissions of those metallic elements from industrialization of some sites in the Tarnobrzeska Plain. Cadmium was at elevated concentrations in L. versipelle from the Tarnobrzeska Plain but the reason-pollution or geogenic source-was unknown, while it was at typical concentrations in other species.

  14. Exposure to Crystal Violet, Its Toxic, Genotoxic and Carcinogenic Effects on Environment and Its Degradation and Detoxification for Environmental Safety.

    Science.gov (United States)

    Mani, Sujata; Bharagava, Ram Naresh

    2016-01-01

    Crystal Violet (CV), a triphenylmethane dye, has been extensively used in human and veterinary medicine as a biological stain, as a textile dye in textile processing industries and also used to provide a deep violet color to paints and printing ink. CV is also used as a mutagenic and bacteriostatic agent in medical solutions and antimicrobial agent to prevent the fungal growth in poultry feed. Inspite of its many uses, CV has been reported as a recalcitrant dye molecule that persists in environment for a long period and pose toxic effects in environment. It acts as a mitotic poison, potent carcinogen and a potent clastogene promoting tumor growth in some species of fish. Thus, CV is regarded as a biohazard substance. Although, there are several physico-chemical methods such as adsorption, coagulation and ion-pair extraction reported for the removal of CV, but these methods are insufficient for the complete removal of CV from industrial wastewaters and also produce large quantity of sludge containing secondary pollutants. However, biological methods are regarded as cost-effective and eco-friendly for the treatment of industrial wastewaters, but these methods also have certain limitations. Therefore, there is an urgent need to develop such eco-friendly and cost-effective biological treatment methods, which can effectively remove the dye from industrial wastewaters for the safety of environment, as well as human and animal health.

  15. Behavior toxicity to Caenorhabditis elegans transferred to the progeny after exposure to sulfamethoxazole at environmentally relevant concentrations

    Institute of Scientific and Technical Information of China (English)

    Zhenyang Yu; Lei Jiang; Daqiang Yin

    2011-01-01

    Sulfamethoxazole (SMX) is one of the most common detected antibiotics in the environment. In order to study whether SMX can affect behavior and growth and whether these effects could be transferred to the progeny, Caenorhabditis elegans was exposed at environmentally relevant concentrations for 24, 48, 72 and 96 hr, respectively. After exposure, the exposed parent generation (Po) was measured for behavior and growth indicators, which were presented as percentage of controls (POC). Then their corresponding unexposed progeny (F1) was separated and measured for the same indicators. The lowest POC for Po after 96 hr-exposure at 100 mg/L were 37.8%, 12.7%, 45.8% and 70.1% for body bending frequency (BBF), reversal movement (RM), Omega turns (OT) and body length (BL), respectively. And F1 suffered defects with the lowest POC as 55.8%, 24.1%, 48.5% and 60.7% for BBF, RM, OT and BL, respectively. Defects in both Po and F1 showed a time- and concentration-dependent fashion and behavior indicators showed better sensitivity than growth indicator. The observed effects on F1 demonstrated the transferable properties of SMX. Defects of SMX at environmental concentrations suggested that it is necessary to perform further systematical studies on its ecological risk in actual conditions.

  16. Toxic hydrogen sulfide and dark caves: phenotypic and genetic divergence across two abiotic environmental gradients in Poecilia mexicana.

    Science.gov (United States)

    Tobler, Michael; Dewitt, Thomas J; Schlupp, Ingo; García de León, Francisco J; Herrmann, Roger; Feulner, Philine G D; Tiedemann, Ralph; Plath, Martin

    2008-10-01

    Divergent natural selection drives evolutionary diversification. It creates phenotypic diversity by favoring developmental plasticity within populations or genetic differentiation and local adaptation among populations. We investigated phenotypic and genetic divergence in the livebearing fish Poecilia mexicana along two abiotic environmental gradients. These fish typically inhabit nonsulfidic surface rivers, but also colonized sulfidic and cave habitats. We assessed phenotypic variation among a factorial combination of habitat types using geometric and traditional morphometrics, and genetic divergence using quantitative and molecular genetic analyses. Fish in caves (sulfidic or not) exhibited reduced eyes and slender bodies. Fish from sulfidic habitats (surface or cave) exhibited larger heads and longer gill filaments. Common-garden rearing suggested that these morphological differences are partly heritable. Population genetic analyses using microsatellites as well as cytochrome b gene sequences indicate high population differentiation over small spatial scale and very low rates of gene flow, especially among different habitat types. This suggests that divergent environmental conditions constitute barriers to gene flow. Strong molecular divergence over short distances as well as phenotypic and quantitative genetic divergence across habitats in directions classic to fish ecomorphology suggest that divergent selection is structuring phenotypic variation in this system.

  17. The environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin disrupts morphogenesis of the rat pre-implantation embryo

    Directory of Open Access Journals (Sweden)

    Albertini David F

    2008-01-01

    Full Text Available Abstract Background Environmental toxicants, whose actions are often mediated through the aryl hydrocarbon receptor (AhR pathway, pose risks to the health and well-being of exposed species, including humans. Of particular concern are exposures during the earliest stages of development that while failing to abrogate embryogenesis, may have long term effects on newborns or adults. The purpose of this study was to evaluate the effect of maternal exposure to the AhR-specific ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD on the development of rat pre-implantation embryos with respect to nuclear and cytoskeletal architecture and cell lineage allocation. Results We performed a systematic 3 dimensional (3D confocal microscopy analysis of rat pre-implantation embryos following maternal exposure to environmentally relevant doses of TCDD. Both chronic (50 ng/kg/wk for 3 months and acute (50 ng/kg and 1 μg/kg at proestrus maternal TCDD exposure disrupted morphogenesis at the compaction stage (8–16 cell, with defects including monopolar spindle formation, f-actin capping and fragmentation due to aberrant cytokinesis. Additionally, the size, shape and position of nuclei were modified in compaction stage pre-implantation embryos collected from treated animals. Notably, maternal TCDD exposure did not compromise survival to blastocyst, which with the exception of nuclear shape, were morphologically similar to control blastocysts. Conclusion We have identified the compaction stage of pre-implantation embryogenesis as critically sensitive to the effects of TCDD, while survival to the blastocyst stage is not compromised. To the best of our knowledge this is the first in vivo study to demonstrate a critical window of pre-implantation mammalian development that is vulnerable to disruption by an AhR ligand at environmentally relevant doses.

  18. Study of whole effluent acute toxicity test (Daphnia magna as an evaluation of Ministry of Environment and Forestry Decree No. 3 In 2014 concerning industrial performance rank in environmental management

    Directory of Open Access Journals (Sweden)

    Rohmah Neng

    2018-01-01

    Full Text Available Only 15% of the industries in Citarum Watershed, specifically in Bandung Regency, West Bandung Regency, Sumedang Regency, Bandung City and Cimahi City, are registered as PROPER industries. They must comply to indicators as set in the Minister of Environment and Forestry Decree No. 3 In 2014 concerning Industrial Performance Rank in Environmental Management, as a requirement to apply for PROPER. Wastewater treatment and management, referencing to Minister of Environment and Forestry Decree No. 5 In 2014 concerning Wastewater Effluent Standards, must be performed to be registered as PROPER industries. Conducting only physical-chemical parameter monitoring of wastewater is insufficient to determine the safety of wastewater discharged into the river, therefore additional toxicity tests involving bioindicator are required to determine acute toxicity characteristic of wastewater. The acute toxicity test quantifies LC50 value based on death response of bioindicators from certain dosage. Daphnia magna was used as bioindicator in the toxicity test and probit software for analysis. In 2015-2016, the number of industries that discharged wastewater exceeding the standard was found greater in non-PROPER industries than in PROPER industries. Based on the toxicity level, both PROPER and non-PROPER industries have toxic properties, however PROPER industries of 2015-2016 is more toxic with LC5096 value reaching 2.79%.

  19. Environmental and human exposure assessment monitoring of communities near an abandoned mercury mine in the Philippines: a toxic legacy.

    Science.gov (United States)

    Maramba, Nelia P C; Reyes, Jose Paciano; Francisco-Rivera, Ana Trinidad; Panganiban, Lynn Crisanta R; Dioquino, Carissa; Dando, Nerissa; Timbang, Rene; Akagi, Hirokatsu; Castillo, Ma Teresa; Quitoriano, Carmela; Afuang, Maredith; Matsuyama, Akito; Eguchi, Tomomi; Fuchigami, Youko

    2006-10-01

    Abandoned mines are an important global concern and continue to pose real or potential threats to human safety and health including environmental damage/s. Very few countries had government mine regulation and reclamation policies until the latter part of the century where legal, financial and technical procedures were required for existing mining operations. Major reasons for mine closure may be mainly due to poor economies of the commodity making mining unprofitable, technical difficulties and national security. If the mine is abandoned, more often than not it is the government that shoulders the burden of clean-up, monitoring and remediation. The topic of abandoned mines is complex because of the associated financial and legal liability implications. Abandoned mercury mines have been identified as one of the major concerns because of their significant long-term environmental problems. Primary mercury production is still ongoing in Spain, Kyrgzystan, China, Algeria, Russia and Slovakia while world production declined substantially in the late 1980s. In the Philippines, the mercury mine located southeast of Manila was in operation from 1955 to 1976, before ceasing operation because of the decline in world market price for the commodity. During this time, annual production of mercury was estimated to be about 140,000 kg of mercury yearly. Approximately 2,000,000 t of mine-waste calcines (retorted ore) were produced during mining and roughly 1,000,000 t of these calcines were dumped into nearby Honda Bay to construct a jetty to facilitate mine operations where about 2000 people reside in the nearby three barangays. In October, 1994 the Department of Health received a request from the Provincial Health Office for technical assistance relative to the investigation of increasing complaints of unusual symptoms (e.g. miscarriages, tooth loss, muscle weakness, paralysis, anemia, tremors, etc.) among residents of three barangays. Initial health reports revealed significant

  20. An efficient, block-by-block algorithm for inverting a block tridiagonal, nearly block Toeplitz matrix

    International Nuclear Information System (INIS)

    Reuter, Matthew G; Hill, Judith C

    2012-01-01

    We present an algorithm for computing any block of the inverse of a block tridiagonal, nearly block Toeplitz matrix (defined as a block tridiagonal matrix with a small number of deviations from the purely block Toeplitz structure). By exploiting both the block tridiagonal and the nearly block Toeplitz structures, this method scales independently of the total number of blocks in the matrix and linearly with the number of deviations. Numerical studies demonstrate this scaling and the advantages of our method over alternatives.

  1. Analysis of Block OMP using Block RIP

    OpenAIRE

    Wang, Jun; Li, Gang; Zhang, Hao; Wang, Xiqin

    2011-01-01

    Orthogonal matching pursuit (OMP) is a canonical greedy algorithm for sparse signal reconstruction. When the signal of interest is block sparse, i.e., it has nonzero coefficients occurring in clusters, the block version of OMP algorithm (i.e., Block OMP) outperforms the conventional OMP. In this paper, we demonstrate that a new notion of block restricted isometry property (Block RIP), which is less stringent than standard restricted isometry property (RIP), can be used for a very straightforw...

  2. Solubilization of trace organics in block copolymer micelles for environmental separation using membrane extraction principles. Progress report, May 1, 1992--December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Hatton, T.A.

    1992-12-01

    The solubilization of a range of polycyclic aromatic hydrocarbons in block copolymer micelles has been studied as a function of polymer composition, architecture, and temperature. Micelle formation is favored at high temperatures, leading to significant enhancements in solubilization capacity. At low temperatures, however, micelles do not form and the solubilization capacity of the block copolymer solution for the organics is low; this provides a convenient method for the regeneration of micellar solutions used as ``solvents`` in the treatment of contaminated feed streams using membrane extraction principles. It has also been shown (in collaboration with K.P. Johnston of University of Texas, Austin) that supercritical CO{sub 2} can be used effectively for micelle regeneration. Theoretical calculations of the structure of block copolymer micelles in the presence and absence of solutes using self-consistent mean-field lattice theories have successfully captured the trends observed with changing polymer composition and architecture, often quantitatively. The temperature and composition dependence of the micellar properties were determined by allowing the individual polymer segments to assume both polar and non-polar conformations.

  3. Environmental interventions based on the Health Belief Model and the Ecological-social model in the continuation of consumption of rice, free from toxic metals

    Science.gov (United States)

    Shafiei, Leili; Maleki, Afshin; Sayehmiri, Kourosh

    2018-01-01

    Background and aim Continuation of healthy nutritional behaviors is one of the important factors in effectiveness of educational intervention programs. The aim of this research is to compare the Health Belief Model and the Ecological-social model in reducing consumption of rice contaminated with toxic metals after completion of environmental intervention and continuation of consumption of healthy rice. Methods This research was the implementation of a six-month randomized controlled trial interventional program in two groups’ interventions along with a control group, with 80 people for each group totally, amounting to 240 women, between 18 and 50 years of age in Ilam, Iran in 2014. The questionnaires of the three groups consisted of demographic information, knowledge, the constructs of the models, performance of rice consumption. Friedman test and repeated measures used for data analysis with SPSS (version 20), and confidence interval of 95% were considered. Results The results of the Friedman test indicated a significant increase in the number of women consuming healthy rice over six months after intervention in both intervention groups (pintervention (pintervention methods caused the altered diet of people regarding consumption of healthy rice over six months after the intervention. Increased social support also probably had a more effective role in continuation of healthy diet among the people. PMID:29588814

  4. Introducing Toxics

    OpenAIRE

    David C. Bellinger

    2013-01-01

    With this inaugural issue, Toxics begins its life as a peer-reviewed, open access journal focusing on all aspects of toxic chemicals. We are interested in publishing papers that present a wide range of perspectives on toxicants and naturally occurring toxins, including exposure, biomarkers, kinetics, biological effects, fate and transport, treatment, and remediation. Toxics differs from many other journals in the absence of a page or word limit on contributions, permitting authors to present ...

  5. Toxic Release Inventory Chemicals by Groupings

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) makes available information for more than 600 toxic chemicals that are being used, manufactured, treated, transported, or released...

  6. Information Search of Toxic-Free Ammunition

    National Research Council Canada - National Science Library

    Adelman, Stephen

    1994-01-01

    Task Order No. 0001, Information Search of Toxic-Free Ammunition addresses issues related to toxic and environmentally harmful effects caused by the use of some of the current small arms ammunition...

  7. Toxic chemicals: risk prevention through use reduction

    National Research Council Canada - National Science Library

    Higgins, Thomas E; Sachdev, Jayanti A; Engleman, Stephen A

    2011-01-01

    ... on the actual toxicity of chemicals currently in use, discusses variables that contribute to the relative toxicity of a substance, compares alternate emphases in existing programs for reducing environmental...

  8. Genetic susceptibility to environmental toxicants

    DEFF Research Database (Denmark)

    2001-01-01

    The toxicological challenges to the chemical industry have in recent years been greatly affected by the rapid innovation and development of analytical, molecular and genetic technologies. ECETOC recognises the importance of developing the technical and intellectual skill bases in academia...... and industrial based laboratories to meet the rapid development of the science base of toxicology. As the technology to determine genetic susceptibility develops, so scientist will be able to describe altered gene expression provoked by chemicals long before they are able to offer valid interpretations...... to take toxicological data and both interpret and extrapolate it in a manner as to cause exaggerated concern. The challenge to the toxicologist is to explain what data means and in a way that inspires the confidence in those who have to apply data to the assessment of hazard and risk management. It seems...

  9. Aircraft Environmental System Mechanic, 2-9. Block II--Air Conditioning Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This publication contains a teaching guide and student instructional materials for conducting a high school or adult vocational education course to train persons to perform duties as an aircraft environmental systems mechanic. Course content has been adapted from a military course. The instructional design for this course is self-pace and/or small…

  10. Dilated cardiomyopathy and left bundle branch block associated with ingestion of colloidal gold and silver is reversed by British antiLewisite and vitamin E: The potential toxicity of metals used as health supplements

    Science.gov (United States)

    Archer, Stephen Lawrence

    2008-01-01

    A case of left bundle branch block and a dilated, nonhypertrophic cardiomyopathy associated with ingestion of colloidal gold and silver as an ‘energy tonic’ is described. The cardiac disease was reversed within two months by a course of dimercaprol (Akorn Inc, USA) (British antiLewisite) and vitamin E. This is the first case of gold and silver cardiomyopathy in humans, and highlights the risks of these colloidal metal ‘health supplements’. PMID:18464946

  11. Primary Prevention of Congenital Anomalies: Special Focus on Environmental Chemicals and other Toxicants, Maternal Health and Health Services and Infectious Diseases.

    Science.gov (United States)

    Taruscio, Domenica; Baldi, Francesca; Carbone, Pietro; Neville, Amanda J; Rezza, Giovanni; Rizzo, Caterina; Mantovani, Alberto

    2017-01-01

    Congenital anomalies (CA) represent an important fraction of rare diseases, due to the critical role of non-genetic factors in their pathogenesis. CA are the main group of rare diseases in which primary prevention measures will have a beneficial impact. Indeed, since 2013 the European Union has endorsed a body of evidence-based recommendations for CA primary prevention; the recommendations aim at facilitating the inclusion of primary prevention actions the National Rare Disease Plans of EU Member States and encompass different public health fields, from environment through to maternal diseases and lifestyles.The chapter overviews and discusses the assessment of main risk factors for CA, such as environmental toxicants, maternal health and lifestyles and infections, with a special attention to issues that are emerging or need more knowledge.Overall, the availability of CA registries is important for estimating the health burden of CA, identifying possible hotspots, assessing the impact of interventions and addressing further, fit-to-purpose research.The integration of relevant public health actions that are already in place (e.g., control of noxious chemicals, vaccination programmes, public health services addressing chronic maternal conditions) can increase the affordability and sustainability of CA primary prevention. In developing countries with less primary prevention in place and limited overall resources, a first recognition phase may be pivotal in order to identify priority targets. In the meanwhile, policy makers should be made aware that primary prevention of RD supports publicly endorsed societal values like the knowledge-based promotion of health, empowerment, equity and social inclusiveness.

  12. Environmental Risk Assessment Based on High-Resolution Spatial Maps of Potentially Toxic Elements Sampled on Stream Sediments of Santiago, Cape Verde

    Directory of Open Access Journals (Sweden)

    Marina M. S. Cabral Pinto

    2014-10-01

    Full Text Available Geochemical mapping is the base knowledge to identify the regions of the planet with critical contents of potentially toxic elements from either natural or anthropogenic sources. Sediments, soils and waters are the vehicles which link the inorganic environment to life through the supply of essential macro and micro nutrients. The chemical composition of surface geological materials may cause metabolic changes which may favor the occurrence of endemic diseases in humans. In order to better understand the relationships between environmental geochemistry and public health, we present environmental risk maps of some harmful elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn in the stream sediments of Santiago, Cape Verde, identifying the potentially harmful areas in this island. The Estimated Background Values (EBV of Cd, Co, Cr, Ni and V were found to be above the Canadian guidelines for any type of use of stream sediments and also above the target values of the Dutch and United States guidelines. The Probably Effect Concentrations (PEC, above which harmful effects are likely in sediment dwelling organisms, were found for Cr and Ni. Some associations between the geological formations of the island and the composition of stream sediments were identified and confirmed by descriptive statistics and by Principal Component Analysis (PCA. The EBV spatial distribution of the metals and the results of PCA allowed us to establish relationships between the EBV maps and the geological formations. The first two PCA modes indicate that heavy metals in Santiago stream sediments are mainly originated from weathering of underlying bedrocks. The first metal association (Co, V, Cr, and Mn; first PCA mode consists of elements enriched in basic rocks and compatible elements. The second association of variables (Zn and Cd as opposed to Ni; second PCA mode appears to be strongly controlled by the composition of alkaline volcanic rocks and pyroclastic rocks. So, the

  13. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  14. Is ozonation environmentally benign for reverse osmosis concentrate treatment? Four-level analysis on toxicity reduction based on organic matter fractionation.

    Science.gov (United States)

    Weng, Jingxia; Jia, Huichao; Wu, Bing; Pan, Bingcai

    2018-01-01

    Ozonation is a promising option to treat reverse osmosis concentrate (ROC). However, a systematic understanding and assessment of ozonation on toxicity reduction is insufficient. In this study, ROC sampled from a typical industrial park wastewater treatment plant of China was fractionated into hydrophobic acid (HOA), hydrophobic base (HOB), hydrophobic neutral (HON), and hydrophilic fraction (HI). Systematic bioassays covering bacteria, algae, fish, and human cell lines were conducted to reveal the role of ozonation in toxicity variation of the four ROC fractions. HOA in the raw ROC exhibited the highest toxicity, followed by HON and HI. Ozonation significantly reduced total organic carbon (TOC) and UV 254 values in HOA, HON, and HI and their toxicity except in HOB. Correlation analysis indicated that chemical data (TOC and UV 254 ) of HOA and HON correlated well with their toxicities; however, poor correlations were observed for HOB and HI, suggesting that a battery of toxicity assays is necessary. This study indicates that TOC reduction during ozonation could not fully reflect the toxicity issue, and toxicity assessment is required in conjunction with the chemical data to evaluate the effectiveness of ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Gulf of Mexico mud toxicity limitations

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, H.E.; Beardmore, D.H. (Phillips Petroleum Co., Bartlesville, OK (USA)); Stewart, W.S. (Drilling Specialties Co. (US))

    1989-10-01

    Because of the Environmental Protection Agency's recent toxicity limits on drilling mud discharges for offshore Gulf of Mexico, Phillips Petroleum conducted a mud toxicity study based on both field and lab tests. The study, discussed in this article, found the polyanionic cellulose-sulfomethylated quebracho-chrome lignosulfonate mud Phillips had been using would comfortably pass the toxicity limitations. The study also found barite and thinners were of low toxicity, and hydrocarbons and surfactants were highly toxic.

  16. Separations chemistry of toxic metals

    International Nuclear Information System (INIS)

    Smith, P.; Barr, M.; Barrans, R.

    1996-01-01

    Sequestering and removing toxic metal ions from their surroundings is an increasingly active area of research and is gaining importance in light of current environmental contamination problems both within the DOE complex and externally. One method of separating metal ions is to complex them to a molecule (a ligand or chelator) which exhibits specific binding affinity for a toxic metal, even in the presence of other more benign metals. This approach makes use of the sometimes subtle differences between toxic and non-toxic metals resulting from variations in size, charge and shape. For example, toxic metals such as chromium, arsenic, and technetium exist in the environment as oxyanions, negatively charged species with a characteristic tetrahedral shape. Other toxic metals such as actinides and heavy metals are positively charged spheres with specific affinities for particular donor atoms such as oxygen (for actinides) and nitrogen (for heavy metals). In most cases the toxic metals are found in the presence of much larger quantities of less toxic metals such as sodium, calcium and iron. The selectivity of the chelators is critical to the goal of removing the toxic metals from their less toxic counterparts. The approach was to build a ligand framework that complements the unique characteristics of the toxic metal (size, charge and shape) while minimizing interactions with non-toxic metals. The authors have designed ligands exhibiting specificity for the target metals; they have synthesized, characterized and tested these ligands; and they have shown that they exhibit the proposed selectivity and cooperative binding effects

  17. 2011 NATA - Air Toxics Monitors

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes annual (2005 - 2013) statistics of measured ambient air toxics concentrations (in micrograms per cubic meter) and associated risk estimates for...

  18. EnviroAtlas - Phoenix, AZ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  19. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  20. EnviroAtlas - Cleveland, OH - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Cleveland, OH EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded...

  1. The delay of the environmental licensing in oil activities and legal implications regarding the oil block; O atraso do licenciamento ambiental nas atividades petroliferas e as implicacoes atinentes ao cumprimento de prazo de bloco licitados

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Hellen Priscilla Marinho; Xavier, Yanko Marcius de Alencar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    This work intends to demonstrate how the delay in issuing environmental licenses by the appropriate bodies affect the correct fulfillment of the exploratory phase of blocks already bid and rendered to the lessees. Thus, it will be conducted a study of the pertaining legislation to the subject, such as Law n. 6.938/81 and its recent amendment by Complementary Law n. 140/2011, as well as the Resolutions issued by the National Environmental Council (CONAMA), addressing the vital importance of the environmental licensing process to the preservation of the environment ante the installation of potentially harmful activities. It is also acknowledged, through the analysis of articles and paragraphs, that there is a legal gap concerning the deadline for issuance of certain documents required to start the licensing procedure by the companies, which ultimately jeopardizes the fulfillment of their exploration activities in due time. Furthermore, there is not a provision regarding the return of the deadline to the lessee when it is suspended or extended due to licensing delays for reasons beyond its control, which cannot lack a reasonable answer. Therefore, as a conclusion, it will be presented a possible solution, so as to ensure the proper accomplishment of the oil activities combined with the preservation of the environment. (author)

  2. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors to h...

  3. Environmental pathology

    International Nuclear Information System (INIS)

    Mottet, N.K.

    1985-01-01

    This book contains 14 selections. Some of the titles are: Injury by Ionizing Radiations; Urinary System; Immune System; Chemical Carcinogenesis; The Molecular Basis of Environmental Mutagenesis; and Reproductive Toxicity

  4. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  5. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

    International Nuclear Information System (INIS)

    Davis, Catherine C.; Baccam, Mekhine; Mantz, Mary J.; Osborn, Thomas W.; Hill, Donna R.; Squier, Christopher A.

    2014-01-01

    Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen—TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ( 3 H 2 O) through porcine vaginal mucosa was determined at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52 °C) did not significantly increase flux of 3 H 2 O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of 3 H 2 O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. - Highlights: • Model assessed local effects of tampon use on vaginal mucosa. • Risks were evaluated using two tracers to assess permeability in an ex vivo model. • Mechanical damage to the epithelial surface increased tracer penetration. • Surfactants increased

  6. Use of porcine vaginal tissue ex-vivo to model environmental effects on vaginal mucosa to toxic shock syndrome toxin-1

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Catherine C.; Baccam, Mekhine [Feminine Care Global Product Stewardship, 6110 Center Hill Road, The Procter and Gamble Company, Cincinnati, OH 45224 (United States); Mantz, Mary J. [Dows Institute for Dental Research, The University of Iowa, Iowa City, IA 52242 (United States); Osborn, Thomas W.; Hill, Donna R. [Feminine Care Product Development, 6110 Center Hill Road, The Procter and Gamble Company, Cincinnati, OH 45224 (United States); Squier, Christopher A. [Dows Institute for Dental Research, The University of Iowa, Iowa City, IA 52242 (United States)

    2014-01-15

    Menstrual toxic shock syndrome (mTSS) is a rare, recognizable, and treatable disease that has been associated with tampon use epidemiologically. It involves a confluence of microbial risk factors (Staphylococcus aureus strains that produce the superantigen—TSST-1), as well as environmental characteristics of the vaginal ecosystem during menstruation and host susceptibility factors. This paper describes a series of experiments using the well-characterized model of porcine vaginal mucosa ex-vivo to assess the effect of these factors associated with tampon use on the permeability of the mucosa. The flux of radiolabeled TSST-1 and tritiated water ({sup 3}H{sub 2}O) through porcine vaginal mucosa was determined at various temperatures, after mechanical disruption of the epithelial surface by tape stripping, after treatment with surfactants or other compounds, and in the presence of microbial virulence factors. Elevated temperatures (42, 47 and 52 °C) did not significantly increase flux of {sup 3}H{sub 2}O. Stripping of the epithelial layers significantly increased the flux of labeled toxin in a dose-dependent manner. Addition of benzalkonium chloride (0.1 and 0.5%) and glycerol (4%) significantly increased the flux of {sup 3}H{sub 2}O but sodium lauryl sulfate at any concentration tested did not. The flux of the labeled toxin was significantly increased in the presence of benzalkonium chloride but not Pluronic® L92 and Tween 20 and significantly increased with addition of α-hemolysin but not endotoxin. These results show that the permeability of porcine vagina ex-vivo to labeled toxin or water can be used to evaluate changes to the vaginal environment and modifications in tampon materials, and thus aid in risk assessment. - Highlights: • Model assessed local effects of tampon use on vaginal mucosa. • Risks were evaluated using two tracers to assess permeability in an ex vivo model. • Mechanical damage to the epithelial surface increased tracer penetration.

  7. Introducing Toxics

    Directory of Open Access Journals (Sweden)

    David C. Bellinger

    2013-04-01

    Full Text Available With this inaugural issue, Toxics begins its life as a peer-reviewed, open access journal focusing on all aspects of toxic chemicals. We are interested in publishing papers that present a wide range of perspectives on toxicants and naturally occurring toxins, including exposure, biomarkers, kinetics, biological effects, fate and transport, treatment, and remediation. Toxics differs from many other journals in the absence of a page or word limit on contributions, permitting authors to present their work in as much detail as they wish. Toxics will publish original research papers, conventional reviews, meta-analyses, short communications, theoretical papers, case reports, commentaries and policy perspectives, and book reviews (Book reviews will be solicited and should not be submitted without invitation. Toxins and toxicants concern individuals from a wide range of disciplines, and Toxics is interested in receiving papers that represent the full range of approaches applied to their study, including in vitro studies, studies that use experimental animal or non-animal models, studies of humans or other biological populations, and mathematical modeling. We are excited to get underway and look forward to working with authors in the scientific and medical communities and providing them with a novel venue for sharing their work. [...

  8. Testing block subdivision algorithms on block designs

    Science.gov (United States)

    Wiseman, Natalie; Patterson, Zachary

    2016-01-01

    Integrated land use-transportation models predict future transportation demand taking into account how households and firms arrange themselves partly as a function of the transportation system. Recent integrated models require parcels as inputs and produce household and employment predictions at the parcel scale. Block subdivision algorithms automatically generate parcel patterns within blocks. Evaluating block subdivision algorithms is done by way of generating parcels and comparing them to those in a parcel database. Three block subdivision algorithms are evaluated on how closely they reproduce parcels of different block types found in a parcel database from Montreal, Canada. While the authors who developed each of the algorithms have evaluated them, they have used their own metrics and block types to evaluate their own algorithms. This makes it difficult to compare their strengths and weaknesses. The contribution of this paper is in resolving this difficulty with the aim of finding a better algorithm suited to subdividing each block type. The proposed hypothesis is that given the different approaches that block subdivision algorithms take, it's likely that different algorithms are better adapted to subdividing different block types. To test this, a standardized block type classification is used that consists of mutually exclusive and comprehensive categories. A statistical method is used for finding a better algorithm and the probability it will perform well for a given block type. Results suggest the oriented bounding box algorithm performs better for warped non-uniform sites, as well as gridiron and fragmented uniform sites. It also produces more similar parcel areas and widths. The Generalized Parcel Divider 1 algorithm performs better for gridiron non-uniform sites. The Straight Skeleton algorithm performs better for loop and lollipop networks as well as fragmented non-uniform and warped uniform sites. It also produces more similar parcel shapes and patterns.

  9. Poly(ferrocenylsilane)-block-Polylactide Block Copolymers

    NARCIS (Netherlands)

    Roerdink, M.; van Zanten, Thomas S.; Hempenius, Mark A.; Zhong, Zhiyuan; Feijen, Jan; Vancso, Gyula J.

    2007-01-01

    A PFS/PLA block copolymer was studied to probe the effect of strong surface interactions on pattern formation in PFS block copolymer thin films. Successful synthesis of PFS-b-PLA was demonstrated. Thin films of these polymers show phase separation to form PFS microdomains in a PLA matrix, and

  10. Antimony Toxicity

    Directory of Open Access Journals (Sweden)

    Shyam Sundar

    2010-12-01

    Full Text Available Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically.

  11. Real-time environmental monitoring system: drilling campaign BM-CAL-4 Block, Camanu-Almada Basin, Bahia, Brazil; Sistema de monitoramento ambiental em tempo-real: Bloco BM-CAL-4, Bacia de Camamu-Almada, Bahia, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Pedro [El Paso Oleo e Gas, Natal, RN (Brazil); Cabral, Alexandre P. [Fugro OceansatPeg (Brazil)

    2008-07-01

    Between February and November 2007, the El Paso Oleo e Gas do Brasil Ltda. carried out a second exploratory campaign at the BM-CAL-4 Block (Camamu-Almada Basin), installing a real-time transmission metocean data monitoring system. Two metocean Wavescan (WS) buoys from Fugro were installed, transmitting current, wave and wind data to the El Paso crises room. The WS1 was positioned near the oil (10,5 km from the shore, at 22m depth), and the WS2 was located near the entrance of Barra Grande area (4,w km from the coast, at 10m depth). The real rime data fed the mathematical simulation using an oil spill model from Fugro Oceansatpeg. The metocean data Real-Time Environmental Monitoring System proved to be an important tool in the environmental management of the drilling activity located near the coastline. The sampling and real-time transmission of the current, wind and wave data allowed a better decision making regarding the selection of the best response strategies, saving time and resources in the simulation exercises, a vital issue in case of a real oil spill accident. (author)

  12. Antimony Toxicity

    OpenAIRE

    Sundar, Shyam; Chakravarty, Jaya

    2010-01-01

    Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The...

  13. Oxygen toxicity

    Directory of Open Access Journals (Sweden)

    C. A. van der Westhuizen

    1990-07-01

    Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

  14. The toxicity of plutonium

    International Nuclear Information System (INIS)

    Crouse, P.L.

    1994-01-01

    Shipments of plutonium occasionally pass around the Cape coastal waters on its way to Japan from Europe. This invariably leads to a great deal of speculation of the dangers involved and of the extreme toxicity of plutonium, with the media and environmental groups claiming that (a) plutonium is the most toxic substance known to man, and that (b) a few kilograms of plutonium ground finely and dispersed in the atmosphere could kill every human being on earth. Comparisons with other poisons are drawn, e.g. common inorganic chemicals and biological agents. The original scare around the extraordinary toxicity of Pu seems to have started in 1974 with the claims of Tamplin and Cochran's hot particle theory about plutonium lodging in the sensitive portions of the lungs in small concentrated aggregates where they are much more effective in producing cancers. This theory, however, is regarded as thoroughly discredited by the experts in the field of radiotoxicity. 8 refs

  15. Block That Pain!

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Block That Pain! Past Issues / Fall 2007 Table of ... contrast, most pain relievers used for surgical procedures block activity in all types of neurons. This can ...

  16. Bundle Branch Block

    Science.gov (United States)

    ... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

  17. The transferability from rat subacute 4-week oral toxicity study to translational research exemplified by two pharmaceutical immunosuppressants and two environmental pollutants with immunomodulating properties

    NARCIS (Netherlands)

    Kemmerling, J.; Fehlert, E.; Kuper, C.F.; Rühl-Fehlert, C.; Stropp, G.; Vogels, J.; Krul, C.; Vohr, H.W.

    2015-01-01

    Exposure to chemicals may have an influence on the immune system. Often, this is an unwanted effect but in some pharmaceuticals, it is the intended mechanism of action. Immune function tests and in depth histopathological investigations of immune organs were integrated in rodent toxicity studies

  18. FLUORIDE TOXICITY – A HARSH REALITY

    OpenAIRE

    Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

    2011-01-01

    There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...

  19. EnviroAtlas - Milwaukee, WI - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,175 block groups in Milwaukee, Wisconsin. Carbon attributes, temperature reduction,...

  20. EnviroAtlas - Portland, ME - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 146 block groups in Portland, Maine. Carbon attributes, temperature reduction,...

  1. EnviroAtlas - Austin, TX - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 750 block groups in Austin, Texas. Carbon attributes, temperature reduction,...

  2. EnviroAtlas - Memphis, TN - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 703 block groups in Memphis, Tennessee. Carbon attributes, temperature reduction,...

  3. EnviroAtlas - Paterson, NJ - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 107 block groups in Paterson, New Jersey. Carbon attributes, temperature reduction,...

  4. EnviroAtlas - Woodbine, IA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1 block group in Woodbine, Iowa. Carbon attributes, temperature reduction, pollution...

  5. EnviroAtlas - Durham, NC - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 193 block groups in Durham, North Carolina. Carbon attributes, temperature reduction,...

  6. EnviroAtlas - Pittsburgh, PA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,089 block groups in Pittsburgh, Pennsylvania. Carbon attributes, temperature...

  7. EnviroAtlas - Tampa, FL - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,833 block groups in Tampa Bay, Florida. Carbon attributes, temperature reduction,...

  8. EnviroAtlas - Portland, OR - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1176 block groups in Portland, Oregon. Carbon attributes, temperature reduction,...

  9. EnviroAtlas - Fresno, CA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 405 block groups in Fresno, California. Carbon attributes, temperature reduction,...

  10. EnviroAtlas - Cleveland, OH - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,442 block groups in Cleveland, Ohio. Carbon attributes, temperature reduction,...

  11. EnviroAtlas - Phoenix, AZ - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset presents environmental benefits of the urban forest in 2,434 block groups in Phoenix, Arizona. Carbon attributes, pollution removal and value, and...

  12. Lead toxicity: current concerns.

    OpenAIRE

    Goyer, R A

    1993-01-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has be...

  13. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes....

  14. JPRS Report. Environmental Issues

    National Research Council Canada - National Science Library

    1991-01-01

    ... Spieces, Forest COnservation, Toxic Waste, Wildlife, Chernobyl Trial, Industrial, International Environmental,Hydroelectric plants, Fire Extinguished, Cleanup, Chemical Pollution, Ecological Disaster...

  15. The studies on the toxicity mechanism of environmentally hazardous natural (IAA) and synthetic (NAA) auxin--The experiments on model Arabidopsis thaliana and rat liver plasma membranes.

    Science.gov (United States)

    Hąc-Wydro, Katarzyna; Flasiński, Michał

    2015-06-01

    This paper concerns the studies towards membrane-damage effect of two auxins: indole-3-acetic acid - IAA and 1-naphthaleneacetic acid - NAA on plant (Arabidopsis thaliana) and animal (rat liver) model membranes. The foregoing auxins are plant growth regulators widely used in agriculture to control the quality of the crop. However, their accumulation in the environment makes them hazardous for the living organisms. The aim of our investigations was to compare the effect of natural (IAA) vs. synthetic (NAA) auxin on the organization of plant and animal model membranes and find a possible correlation between membrane-disturbing effect of these compounds and their toxicity. The collected data evidenced that auxins cause destabilization of membranes, decrease their condensation and weakens interactions of molecules. The alterations in the morphology of model systems were also noticed. The foregoing effects of auxins are concentration-dependent and additionally NAA was found to act on animal vs. plant membranes more selectively than IAA. Interestingly, both IAA and NAA induce the strongest disordering in model lipid system at the concentration, which is frequently reported as toxic to animal and plants. Based on the above findings it was proposed that membrane-damage effect induced by IAA and NAA may be important from the point of view of the mechanism of toxicity of these compounds and cannot be ignored in further investigations in this area. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Toxic releases from power plants

    International Nuclear Information System (INIS)

    Rubin, E.S.

    1999-01-01

    Beginning in 1998, electric power plants burning coal or oil must estimate and report their annual releases of toxic chemicals listed in the Toxics Release Inventory (TRI) published by the US Environmental Protection Agency (EPA). This paper identifies the toxic chemicals of greatest significance for the electric utility sector and develops quantitative estimates of the toxic releases reportable to the TRI for a representative coal-fired power plant. Key factors affecting the magnitude and types of toxic releases for individual power plants also are discussed. A national projection suggests that the magnitude of electric utility industry releases will surpass those of the manufacturing industries which current report to the TRI. Risk communication activities at the community level will be essential to interpret and provide context for the new TRI results

  17. The Toxicity of Depleted Uranium

    OpenAIRE

    Briner, Wayne

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  18. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  19. 31 CFR 595.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

  20. Data for Barron et al. "Photoenhanced toxicity of weathered crude oil in sediment and water to larval zebrafish" submitted to the Bulletin of Environmental Contamination and Toxicology

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset contains fish mortality associated with various treatment of oil and dispersants in water accommodated fractions and sediment. The dataset also contains...

  1. Predicting refinery effluent toxicity on the basis of hydrocarbon composition determined by GCxGC analysis

    Energy Technology Data Exchange (ETDEWEB)

    Whale, G. [and others

    2013-04-15

    A high resolution analytical method for determining hydrocarbon blocks in petroleum products by comprehensive two-dimensional gas chromatography (GCxGC) was used for the analysis of petroleum hydrocarbons extracted from refinery effluents. From 105 CONCAWE refineries in Europe 111 refinery effluents were collected in the period June 2008 to March 2009 (CONCAWE, 2010). The effluents were analysed for metals, standard effluent parameters (including Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), oil in water (OiW), GCxGC speciated hydrocarbons, BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) and volatile organic compounds. This report describes the subsequent analysis of the GCxGC data, as described in hydrocarbon blocks, and uses the PETROTOX model, to predict the environmental toxicity (i.e. ecotoxicity) of the discharged effluents. A further analysis was undertaken to address the potential environmental impact of these predicted effects initially using default dilution factors and then,when necessary site specific factors. The report describes all the methods used to arrive at the predictions, and shows that for the majority of refinery effluents direct toxicity effects in the effluents are not anticipated. Furthermore, when applying either the EU Risk Assessment Technical Guidance Document (TGD) default dilution factors or site specific dilution factors, none of the refineries are predicted to exerting either acute or chronic toxicity to organisms in the receiving aquatic environment, based on their hydrocarbon composition present in the effluent samples.

  2. Block Cipher Analysis

    DEFF Research Database (Denmark)

    Miolane, Charlotte Vikkelsø

    ensurethat no attack violatesthe securitybounds specifiedbygeneric attack namely exhaustivekey search and table lookup attacks. This thesis contains a general introduction to cryptography with focus on block ciphers and important block cipher designs, in particular the Advanced Encryption Standard(AES...... on small scale variants of AES. In the final part of the thesis we present a new block cipher proposal Present and examine its security against algebraic and differential cryptanalysis in particular....

  3. The role of social toxicity in responses to a slowly-evolving environmental disaster: the case of amphibole asbestos exposure in Libby, Montana, USA.

    Science.gov (United States)

    Cline, Rebecca J W; Orom, Heather; Chung, Jae Eun; Hernandez, Tanis

    2014-09-01

    Experiencing a disaster has significant negative effects on psychological adjustment. Case study accounts point to two consistent trends in slowly-evolving environmental disasters: (a) patterns of negative social dynamics, and (b) relatively worse psychological outcomes than in natural disasters. Researchers have begun to explicitly postulate that the social consequences of slowly-evolving environmental disasters (e.g., community conflict) have their own effects on victims' psychological outcomes. This study tested a model of the relationship between those social consequences and psychological adjustment of victims of a slowly-evolving environmental disaster, specifically those whose health has been compromised by the amphibole asbestos disaster in Libby, MT. Results indicate that experiencing greater community conflict about the disaster was associated with greater family conflict about the disaster which, in turn, was associated with greater social constraints on talking with others about their disease, both directly and indirectly through experiencing stigmatization. Experiencing greater social constraints was associated with worse psychological adjustment, both directly and indirectly through failed social support. Findings have implications for understanding pathways by which social responses create negative effects on mental health in slowly-evolving environmental disasters. These pathways suggest points for prevention and response (e.g., social support, stigmatization of victims) for communities experiencing slowly-evolving environmental disasters.

  4. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix.

  5. Designers Block 2002

    DEFF Research Database (Denmark)

    Dickson, Thomas

    2002-01-01

    Artiklen indleder med: ved siden aaf Londons etablerede designmesse '100% Design', er der vokset et undergrundsmiljø af designudstillinger op. Det dominerende og mest kendte initiativ er Designers Block, der i år udstillede to steder i byen. Designers Block er et mere uformelt udstillingsforum...

  6. Microcystis aeruginosa : source of toxic microcystins in drinking water

    African Journals Online (AJOL)

    , which is the most common toxic cyanobacterium in eutrophic freshwater. The association of environmental parameters with cyanobacterial blooms and the toxicity of microcystin are discussed. Also, the synthesis of the microcystins, as well as ...

  7. Toxic shock syndrome

    Science.gov (United States)

    Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

  8. Human Toxicity

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Fantke, Peter

    2015-01-01

    all chemicals and impact pathways characterizes the contribution of each factor to the total variation of 10–12 orders of magnitude in impacts per kg across all chemicals. This large variation between characterisation factors for different chemicals as well as the 3 orders of magnitude uncertainty....... As a whole, the assessment of toxicity in LCA has progressed on a very sharp learning curve during the past 20 years. This rapid progression is expected to continue in the coming years, focusing more on direct exposure of workers to chemicals during manufacturing and of consumers during product use...

  9. Control of air toxics

    International Nuclear Information System (INIS)

    Livengood, C.D.

    1995-01-01

    For more than 10 years, Argonne National Laboratory has supported the US DOE's Flue Gas Cleanup Program objective by developing new or improved environmental controls for industries that use fossil fuels. Argonne's pollutant emissions research has ranged from experiments in the basic chemistry of pollution-control systems, through laboratory-scale process development and testing, to pilot-scale field tests of several technologies. The work on air toxics is currently divided into two components: Investigating measures to improve the removal of mercury in existing pollution-control systems applied to coal combustion; and, Developing sensors and control techniques for emissions found in the textile industry

  10. Predictability of blocking

    International Nuclear Information System (INIS)

    Tosi, E.; Ruti, P.; Tibaldi, S.; D'Andrea, F.

    1994-01-01

    Tibaldi and Molteni (1990, hereafter referred to as TM) had previously investigated operational blocking predictability by the ECMWF model and the possible relationships between model systematic error and blocking in the winter season of the Northern Hemisphere, using seven years of ECMWF operational archives of analyses and day 1 to 10 forecasts. They showed that fewer blocking episodes than in the real atmosphere were generally simulated by the model, and that this deficiency increased with increasing forecast time. As a consequence of this, a major contribution to the systematic error in the winter season was shown to derive from the inability of the model to properly forecast blocking. In this study, the analysis performed in TM for the first seven winter seasons of the ECMWF operational model is extended to the subsequent five winters, during which model development, reflecting both resolution increases and parametrisation modifications, continued unabated. In addition the objective blocking index developed by TM has been applied to the observed data to study the natural low frequency variability of blocking. The ability to simulate blocking of some climate models has also been tested

  11. Assessment of darkling beetle fauna after implementation of an environmental restoration program in the southern Iberian Peninsula affected by the Aznalcóllar toxic spill.

    Science.gov (United States)

    Cárdenas, Ana M; Bujalance, José L; Hidalgo, Juan M

    2011-01-01

    This study is part of the Follow up Restoration Program of animal communities that colonize the Guadiamar River Basin. In 1998, the area was affected by a release of toxic sludge after the retention walls of the Aznalcóllar Mines (southern Iberian Peninsula) broke. The main objective of this study was to assess the current state of the population of Tenebrionidae, one of the most representative groups of edaphic Coleoptera inhabiting the Guadiamar River Basin. This paper analyses the progress made by the darkling beetle community six years after the disaster occurred and the Restoration Program was implemented. The study is based on faunistic data from systematic sampling carried out for six years to monitor plots distributed across the damaged area. To make an overall assessment of the tenebrionid fauna in relation to adjacent areas qualitative and quantitative ecological indices were applied, and temporal follow up and biogeographical comparisons were also made. The results indicate that, on the whole, tenebrionid fauna was somewhat affected by the Aznalcóllar Mine spill, and that a greater loss of fauna was detected closer to the accident site. The analysis of the temporal population dynamic suggests that the most affected zones are undergoing a process of re-colonization. However, this process varies widely by species and has not yet reached the expected levels of a non-affected river basin in the southern Iberian Peninsula.

  12. 31 CFR 594.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY GLOBAL TERRORISM SANCTIONS REGULATIONS General Definitions § 594.301 Blocked account; blocked property. The terms blocked account and...

  13. RX for Writer's Block.

    Science.gov (United States)

    Tompkins, Gail E.; Camp, Donna J.

    1988-01-01

    Describes four prewriting techniques that elementary and middle grade students can use to gather and organize ideas for writing, and by so doing, cure writer's block. Techniques discussed are: (1) brainstorming; (2) clustering; (3) freewriting; and (4) cubing.

  14. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  15. Toxicity Assessment for EPA's Hydraulic Fracturing Study

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains data used to develop multiple manuscripts on the toxicity of chemicals associated with the hydraulic fracturing industry. These manuscripts...

  16. Mobile source air toxics mitigation measures.

    Science.gov (United States)

    2013-10-01

    In accordance with the Federal Highway Administration (FHWA) Interim Guidance Update on Mobile Source Air Toxic Analysis in NEPA Documents (September 30, 2009), transportation projects subject to the National Environmental Policy Act (NEPA) mus...

  17. Anaerobic Toxicity of Cationic Silver Nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — Toxicity data for the impact of nano-silver on anaerobic degradation. This dataset is associated with the following publication: Gitipour, A., S. Thiel, K. Scheckel,...

  18. Blocking in Category Learning

    OpenAIRE

    Bott, Lewis; Hoffman, Aaron B.; Murphy, Gregory L.

    2007-01-01

    Many theories of category learning assume that learning is driven by a need to minimize classification error. When there is no classification error, therefore, learning of individual features should be negligible. We tested this hypothesis by conducting three category learning experiments adapted from an associative learning blocking paradigm. Contrary to an error-driven account of learning, participants learned a wide range of information when they learned about categories, and blocking effe...

  19. Betaine-based heat transfer fluids as a natural solution for environmental, toxic and corrosion problems in heating and cooling systems; Betaine gebaseerde koudedragers als natuurlijke oplossing voor milieu-, toxiciteit- en corrosieproblemen in verwarming- en koelsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, J. [Fortum Oil and Gas Oy, Porvoo (Finland); Willems, B.P.M. [Marketing and Technology Consult, Rijen (Netherlands)

    2005-02-01

    The reason for the study on the title subject was the environmental risk and toxicity of many conventional heat transfer fluids like glycols. Fluid toxicity and environmental risk in building systems and industrial use is becoming less acceptable. Alternative fluids have been sought from among salt solutions and vegetable oils. Still, those alternative materials are not very attractive. Main technical problems have been high viscosity and corrosion. A new possible alternative, a betaine-water solution was tested and developed for heat transfer purposes. Betaine (trimethyl glycine) is a by-product of the sugar industry. Therefore, betaine is completely non-toxic and also not harmful to the environment. Betaine is a renowned substance in the pharmaceutical, cosmetic, food and medical industry. Adequate freezing protection is achieved with betaine concentration of 20-55% by weight. This solution was found to have other good qualities also; it has good heat transfer abilities, is not harmful to materials used in systems and has natural corrosion protection properties. The development work consisted of carefully measuring freeze protection and pipe burst protection with different betaine concentrations, measuring physical properties in the same circumstances and developing the additive package for enhanced corrosion protection. Field-testing was carried out for four years. Testing showed that a betaine-water solution has good thermodynamic properties to be used as a heat transfer fluid in the HVAC industry, with additional environmental-, non-toxic and corrosion properties. The concrete result was a trademark and patent protected new product for the industry. [Dutch] Warmteoverdracht wordt heden ten dage veelvuldig toegepast in zowel de industrie als in kantoren en gebouwen. Hoewel de warmteoverdrachttechnologie enorm is vooruitgegaan worden het potentieel en de voordelen van een zorgvuldig gekozen koudedrager vaak over het hoofd gezien. De selectie van de juiste

  20. Molecular toxicity mechanism of nanosilver

    Directory of Open Access Journals (Sweden)

    Danielle McShan

    2014-03-01

    Full Text Available Silver is an ancient antibiotic that has found many new uses due to its unique properties on the nanoscale. Due to its presence in many consumer products, the toxicity of nanosilver has become a hot topic. This review summarizes recent advances, particularly the molecular mechanism of nanosilver toxicity. The surface of nanosilver can easily be oxidized by O2 and other molecules in the environmental and biological systems leading to the release of Ag+, a known toxic ion. Therefore, nanosilver toxicity is closely related to the release of Ag+. In fact, it is difficult to determine what portion of the toxicity is from the nano-form and what is from the ionic form. The surface oxidation rate is closely related to the nanosilver surface coating, coexisting molecules, especially thiol-containing compounds, lighting conditions, and the interaction of nanosilver with nucleic acids, lipid molecules, and proteins in a biological system. Nanosilver has been shown to penetrate the cell and become internalized. Thus, nanosilver often acts as a source of Ag+ inside the cell. One of the main mechanisms of toxicity is that it causes oxidative stress through the generation of reactive oxygen species and causes damage to cellular components including DNA damage, activation of antioxidant enzymes, depletion of antioxidant molecules (e.g., glutathione, binding and disabling of proteins, and damage to the cell membrane. Several major questions remain to be answered: (1 the toxic contribution from the ionic form versus the nano-form; (2 key enzymes and signaling pathways responsible for the toxicity; and (3 effect of coexisting molecules on the toxicity and its relationship to surface coating.

  1. Environmental cadmium and lead concentrations in the Bahía Blanca Estuary (Argentina. Potential toxic effects of Cd and Pb on crab larvae

    Directory of Open Access Journals (Sweden)

    Laura Ferrer

    2000-12-01

    Full Text Available The Bahía Blanca Estuary includes a large tidal plain with an area close to 1150 km2. Mud is predominant in its sediments, where a significant population of the crab Chasmagnathus granulata lives during the whole year. Moreover, there are important urban and industrial discharges into this environment. Cd and Pb concentrations were determined in samples of water (for both dissolved and suspended particulate matter and surface sediments (total and 63 µm fractions. Organic matter was analysed in the sediments, while temperature, salinity, pH and dissolved oxygen were measured in the estuarine water. The metal concentrations determined in this study were: 1.47 ± 1.08 µg Cd g–1 and 14.68 ± 4.31 µg Pb g–1 in surface sediments; 2.21 ± 1.33 µg Cd g–1 and 25.70 ± 7.09 µg Pb g–1 in the –1 and below the analytical detection limit of Pb in suspended particulate matter. Furthermore, dissolved Cd and Pb were lower than the norms for marine and estuarine waters (2 µg dm–3 for Cd and 5 µg dm–3 for Pb, E.P.A.. Simultaneously, the effects of Cd and Pb were studied on recently hatched larvae of Ch. granulata, through 96-hour semi-static acute assays. Viability was the criterion assessed in the assays. LC50 (96 h for Cd was 46.43 µg dm–3 (36.92 - 56.34 µg dm–3, whilst that for Pb was 1.00 mg m–3 (0.79 - 1.23 mg dm–3, which demonstrates that Cd is more toxic towards larvae. Finally, both LC50 values determined for Cd and Pb were higher than the corresponding metal concentrations measured in the Bahía Blanca environment.

  2. Bioavailability of potentially toxic elements in soil-grapevine (leaf, skin, pulp and seed) system and environmental and health risk assessment.

    Science.gov (United States)

    Milićević, Tijana; Urošević, Mira Aničić; Relić, Dubravka; Vuković, Gordana; Škrivanj, Sandra; Popović, Aleksandar

    2018-06-01

    Monitoring of potentially toxic elements in agricultural soil represents the first measure of caution regarding food safety, while research into element bioavailability should be a step forward in understanding the element transportation chain. This study was conducted in the grapevine growing area ("Oplenac Wine Route") for investigating element bioavailability in the soil-grapevine system accompanied by an assessment of the ecological implications and human health risk. Single extraction procedures (CH 3 COOH, Na 2 EDTA, CaCl 2 , NH 4 NO 3 and deionised H 2 O) and digestion were performed to estimate the bioavailability of 22 elements (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Sr, V and Zn) from the topsoil (0-30 cm) and subsoil (30-60 cm) to the grapevine parts (leaf, skin, pulp and seed) and wine. The extractants were effective comparing to the pseudo-total concentrations in following order Na 2 EDTA ˃ CH 3 COOH ˃ NH 4 NO 3  ˃ CaCl 2 , H 2 O 2 h and 16 h. The most suitable extractants for assessing the bioavailability of the elements from the soil to the grapevine parts were CaCl 2 , NH 4 NO 3 and Na 2 EDTA, but deionised H 2 O could be suitable, as well. The results showed that Ba was the most bioavailable element in the soil-grapevine system. Contamination factor implied a moderate contamination (1  1), the influence of atmospheric deposition on the aerial grapevine parts (leaves and grape skin) was observed. Nevertheless, low adverse health risk effects (HI wine consumers. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Toxicity of TiO2 nanoparticles on soil nitrification at environmentally relevant concentrations: Lack of classical dose-response relationships.

    Science.gov (United States)

    Simonin, Marie; Martins, Jean M F; Le Roux, Xavier; Uzu, Gaëlle; Calas, Aude; Richaume, Agnès

    2017-03-01

    Titanium-dioxide nanoparticles (TiO 2 -NPs) are increasingly released in agricultural soils through, e.g. biosolids, irrigation or nanoagrochemicals. Soils are submitted to a wide range of concentrations of TiO 2 -NPs depending on the type of exposure. However, most studies have assessed the effects of unrealistically high concentrations, and the dose-response relationships are not well characterized for soil microbial communities. Here, using soil microcosms, we assessed the impact of TiO 2 -NPs at concentrations ranging from 0.05 to 500 mg kg -1  dry-soil, on the activity and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nitrite-oxidizing bacteria (Nitrobacter and Nitrospira). In addition, aggregation and oxidative potential of TiO 2 -NPs were measured in the spiking suspensions, as they can be important drivers of TiO 2 -NPs toxicity. After 90 days of exposure, non-classical dose-response relationships were observed for nitrifier abundance or activity, making threshold concentrations impossible to compute. Indeed, AOA abundance was reduced by 40% by TiO 2 -NPs whatever the concentration, while Nitrospira was never affected. Moreover, AOB and Nitrobacter abundances were decreased mainly at intermediate concentrations nitrification was reduced by 25% at the lowest (0.05 mg kg -1 ) and the highest (100 and 500 mg kg -1 ) TiO 2 -NPs concentrations. Path analyses indicated that TiO 2 -NPs affected nitrification through an effect on the specific activity of nitrifiers, in addition to indirect effects on nitrifier abundances. Altogether these results point out the need to include very low concentrations of NPs in soil toxicological studies, and the lack of relevance of classical dose-response tests and ecotoxicological dose metrics (EC50, IC50…) for TiO 2 -NPs impact on soil microorganisms.

  4. Portable, accurate toxicity testing

    International Nuclear Information System (INIS)

    Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L.; Hinds, A.A.; Vieaux, G.J.

    1994-01-01

    Ever tightening environmental regulations, severe penalties for non-compliance, and expensive remediation costs have stimulated development of methods to detect and measure toxins. Most of these methods are bioassays that must be performed in the laboratory; none previously devised has been truly portable. The US Army, through the Small Business Innovative Research program, has developed a hand-held, field deployable unit for testing toxicity of battlefield water supplies. This patented system employs the measurable quenching, in the presence of toxins, of the natural bioluminescence produced by the marine dinoflagellate alga Pyrocystis lunula. The procedure's inventor used it for years to measure toxicity concentrations of chemical warfare agents actually, their simulants, primarily in the form of pesticides and herbicides plus assorted toxic reagents, waterbottom samples, drilling fluids, even blood. While the procedure is more precise, cheaper, and faster than most bioassays, until recently it was immobile. Now it is deployable in the field. The laboratory apparatus has been proven to be sensitive to toxins in concentrations as low as a few parts per billion, repeatable within a variation of 10% or less, and unlike some other bioassays effective in turbid or colored media. The laboratory apparatus and the hand-held tester have been calibrated with the EPA protocol that uses the shrimplike Mysidopsis bahia. The test organism tolerates transportation well, but must be rested a few hours at the test site for regeneration of its light-producing powers. Toxicity now can be measured confidently in soils, water columns, discharge points, and many other media in situ. Most significant to the oil industry is that drilling fluids can be monitored continuously on the rig

  5. Contaminant mixtures and repoductive health: Developmental toxicity effects in rats after mixed exposure to environmentally relevant endocrine disrupting chemicals, with focus on effects in females

    DEFF Research Database (Denmark)

    Jacobsen, Pernille Rosenskjold; Christiansen, Sofie; Hass, Ulla

    proposed that a similar syndrome, called the ovarian dysgenesis syndrome (ODS), exists for females. This syndrome encompasses alterations in reproductive development caused by chemical exposure in sensitive windows of development that may result in fecundity impairments, gravid diseases, gynecological...... disorders or later onset adult diseases. However, experimental evidence on the effects of developmental exposure to environmentally relevant endocrine disrupting chemicals in females has been missing attention. Since chemical exposure can affect female reproductive development it is important to investigate......, mixtures were modeled based on high end human intakes, and the project involved two developmental mixture studies in rats, called Contamed 1 and 2. In these studies 13 chemicals where data on in vivo endocrine disrupting effects and information on human exposures was available, were selected. The tested...

  6. EnviroAtlas - Portland, OR - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  7. EnviroAtlas - Green Bay, WI - Residents with Potential Window Views of Trees by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the total block group population and the percentage of the block group population that has little access to potential window views of...

  8. EnviroAtlas - Portland, ME - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  9. EnviroAtlas - Austin, TX - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  10. EnviroAtlas - Pittsburgh, PA - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  11. EnviroAtlas - New Bedford, MA - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  12. EnviroAtlas - Paterson, NJ - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  13. EnviroAtlas - Durham, NC - Residents with Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  14. EnviroAtlas - Des Moines, IA - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  15. EnviroAtlas - Woodbine, IA - Residents with Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  16. EnviroAtlas - Phoenix, AZ - Residents with Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  17. EnviroAtlas - Green Bay, WI - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  18. EnviroAtlas - Milwaukee, WI - Residents with Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  19. EnviroAtlas - Tampa, FL - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of waterbodies. A potential...

  20. EnviroAtlas - Fresno, CA - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  1. EnviroAtlas - New York, NY - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  2. EnviroAtlas - Minneapolis/St. Paul, MN - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  3. EnviroAtlas - Memphis, TN - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  4. EnviroAtlas - Paterson, NJ - Residents with Potential Window Views of Trees by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the total block group population and the percentage of the block group population that has little access to potential window views of...

  5. EnviroAtlas - Cleveland, OH - Potential Window Views of Water by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the block group population and the percentage of the block group population that has potential views of water bodies. A potential...

  6. Toxicological effects of chemical constituents from Piper against the environmental burden Aedes aegypti Liston and their impact on non-target toxicity evaluation against biomonitoring aquatic insects.

    Science.gov (United States)

    Vasantha-Srinivasan, Prabhakaran; Thanigaivel, Annamalai; Edwin, Edward-Sam; Ponsankar, Athirstam; Senthil-Nathan, Sengottayan; Selin-Rani, Selvaraj; Kalaivani, Kandaswamy; Hunter, Wayne B; Duraipandiyan, Veeramuthu; Al-Dhabi, Naif Abdullah

    2018-04-01

    Dengue is the most rapidly spreading mosquito-borne viral disease in the world. The mosquito, Aedes aegypti, also spreads Yellow fever, Chikungunya, and Zika virus. As the primary vector for dengue, Ae. aegypti now occurs in over 20 countries and is a serious concern with reports of increasing insecticide resistance. Developing new treatments to manage mosquitoes are needed. Formulation of crude volatile oil from Piper betle leaves (Pb-CVO) was evaluated as a potential treatment which showed larvicidal, ovipositional, and repellency effects. Gut-histology and enzyme profiles were analyzed post treatment under in-vitro conditions. The Pb-CVO from leaves of field collected plants was obtained by steam distillation and separated through rotary evaporation. The Pb-CVO were evaluated for chemical constituents through GC-MS analyses revealed 20 vital compounds. The peak area was establish to be superior in Eudesm-7(11)-en-4-ol (14.95%). Pb-CVO were determined and tested as four different concentrations (0.25, 0.5, 1.0, and 1.5 mg/L) of Pb-CVO towards Ae. aegypti. The larvicidal effects exhibited dose dependent mortality being greatest at 1.5 mg Pb-CVO/10 g leaves. The LC 50 occurred at 0.63 mg Pb-CVO/L. Larva of Ae. aegypti exposed to Pb-CVO showed significantly reduced digestive enzyme actions of α- and β-carboxylesterases. In contrast, GST and CYP450 enzyme levels increased significantly as concentration increased. Correspondingly, oviposition deterrence index and egg hatch of Ae. aegypti exposed to sub-lethal doses of Pb-CVO demonstrated a strong effect suitable for population suppression. Repellency at 0.6 mg Pb-CVO applied as oil had a protection time of 15-210 min. Mid-gut histological of Ae. aegypti larvae showed severe damage when treated with 0.6 mg of Pb-CVO treatment compared to the control. Non-toxic effects against aquatic beneficial insects, such as Anisops bouvieri and Toxorhynchites splendens, were observed at the highest concentrations, exposed

  7. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  8. Impression block with orientator

    International Nuclear Information System (INIS)

    Brilin, V I; Ulyanova, O S

    2015-01-01

    Tool review, namely the impression block, applied to check the shape and size of the top of fish as well as to determine the appropriate tool for fishing operation was realized. For multiple application and obtaining of the impress depth of 3 cm and more, the standard volumetric impression blocks with fix rods are used. However, the registered impress of fish is not oriented in space and the rods during fishing are in the extended position. This leads to rods deformation and sinking due to accidental impacts of impression block over the borehole irregularity and finally results in faulty detection of the top end of fishing object in hole. The impression blocks with copy rods and fixed magnetic needle allow estimating the object configuration and fix the position of magnetic needle determining the position of the top end of object in hole. However, the magnetic needle fixation is realized in staged and the rods are in extended position during fishing operations as well as it is in standard design. The most efficient tool is the impression block with copy rods which directs the examined object in the borehole during readings of magnetic needles data from azimuth plate and averaging of readings. This significantly increases the accuracy of fishing toll direction. The rods during fishing are located in the body and extended only when they reach the top of fishing object

  9. Modeling Aquatic Toxicity through Chromatographic Systems.

    Science.gov (United States)

    Fernández-Pumarega, Alejandro; Amézqueta, Susana; Farré, Sandra; Muñoz-Pascual, Laura; Abraham, Michael H; Fuguet, Elisabet; Rosés, Martí

    2017-08-01

    Environmental risk assessment requires information about the toxicity of the growing number of chemical products coming from different origins that can contaminate water and become toxicants to aquatic species or other living beings via the trophic chain. Direct toxicity measurements using sensitive aquatic species can be carried out but they may become expensive and ethically questionable. Literature refers to the use of chromatographic measurements that correlate to the toxic effect of a compound over a specific aquatic species as an alternative to get toxicity information. In this work, we have studied the similarity in the response of the toxicity to different species and we have selected eight representative aquatic species (including tadpoles, fish, water fleas, protozoan, and bacteria) with known nonspecific toxicity to chemical substances. Next, we have selected four chromatographic systems offering good perspectives for surrogation of the eight selected aquatic systems, and thus prediction of toxicity from the chromatographic measurement. Then toxicity has been correlated to the chromatographic retention factor. Satisfactory correlation results have been obtained to emulate toxicity in five of the selected aquatic species through some of the chromatographic systems. Other aquatic species with similar characteristics to these five representative ones could also be emulated by using the same chromatographic systems. The final aim of this study is to model chemical products toxicity to aquatic species by means of chromatographic systems to reduce in vivo testing.

  10. EnviroAtlas - Portland, ME - Park Access by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the block group population that is within and beyond an easy walking distance (500m) of a park entrance. Park entrances were included...

  11. EnviroAtlas - Austin, TX - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, and agriculture. Forest is defined as...

  12. EnviroAtlas - Memphis, TN - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, agriculture, and wetlands. Forest is...

  13. EnviroAtlas - Portland, OR - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...

  14. EnviroAtlas - Fresno, CA - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...

  15. EnviroAtlas - Tampa, FL - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, wetland, and agriculture. Impervious is...

  16. EnviroAtlas - Portland, ME - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, wetland, and agriculture. Impervious is...

  17. EnviroAtlas - New York, NY - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the New York, NY EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded based...

  18. EnviroAtlas - Woodbine, IA - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...

  19. EnviroAtlas - Cleveland, OH - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, green space, and wetlands. In this community, forest...

  20. EnviroAtlas - Paterson, NJ - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is just trees and forest....

  1. EnviroAtlas - Phoenix, AZ - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, agriculture, and green space. Forest is combination...

  2. EnviroAtlas - Pittsburgh, PA - Land Cover by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of each block group that is classified as impervious, forest, and green space. Forest is combination of trees and...

  3. Environmental microbiology

    Science.gov (United States)

    Briški, Felicita; Vuković Domanovac, Marija

    2017-10-01

    For most people, microorganisms are out of sight and therefore out of mind but they are large, extremely diverse group of organisms, they are everywhere and are the dominant form of life on planet Earth. Almost every surface is colonized by microorganisms, including our skin; however most of them are harmless to humans. Some microorganisms can live in boiling hot springs, whereas others form microbial communities in frozen sea ice. Among their many roles, microorganisms are necessary for biogeochemical cycling, soil fertility, decomposition of dead plants and animals and biodegradation of many complex organic compounds present in the environment. Environmental microbiology is concerned with the study of microorganisms in the soil, water and air and their application in bioremediation to reduce environmental pollution through the biological degradation of pollutants into non-toxic or less toxic substances. Field of environmental microbiology also covers the topics such as microbially induced biocorrosion, biodeterioration of constructing materials and microbiological quality of outdoor and indoor air.

  4. Surviving in a toxic world: transcriptomics and gene expression profiling in response to environmental pollution in the critically endangered European eel

    Directory of Open Access Journals (Sweden)

    Pujolar Jose

    2012-09-01

    Full Text Available Abstract Background Genomic and transcriptomic approaches have the potential for unveiling the genome-wide response to environmental perturbations. The abundance of the catadromous European eel (Anguilla anguilla stock has been declining since the 1980s probably due to a combination of anthropogenic and climatic factors. In this paper, we explore the transcriptomic dynamics between individuals from high (river Tiber, Italy and low pollution (lake Bolsena, Italy environments, which were measured for 36 PCBs, several organochlorine pesticides and brominated flame retardants and nine metals. Results To this end, we first (i updated the European eel transcriptome using deep sequencing data with a total of 640,040 reads assembled into 44,896 contigs (Eeelbase release 2.0, and (ii developed a transcriptomic platform for global gene expression profiling in the critically endangered European eel of about 15,000 annotated contigs, which was applied to detect differentially expressed genes between polluted sites. Several detoxification genes related to metabolism of pollutants were upregulated in the highly polluted site, including genes that take part in phase I of the xenobiotic metabolism (CYP3A, phase II (glutathione-S-transferase and oxidative stress (glutathione peroxidase. In addition, key genes in the mitochondrial respiratory chain and oxidative phosphorylation were down-regulated at the Tiber site relative to the Bolsena site. Conclusions Together with the induced high expression of detoxification genes, the suggested lowered expression of genes supposedly involved in metabolism suggests that pollution may also be associated with decreased respiratory and energy production.

  5. Tartaric Acid as a Non-toxic and Environmentally-Friendly Anti-scaling Material for Using in Cooling Water Systems: Electrochemical and Surface Studies

    Science.gov (United States)

    Asghari, Elnaz; Gholizadeh-Khajeh, Maryam; Ashassi-Sorkhabi, Habib

    2016-10-01

    Because of the major limitations in drinking water resources, the industries need to use unprocessed water sources for their cooling systems; these water resources contain major amount of hardening cations. So, mineral scales are formed in cooling water systems during the time and cause major problems. The use of green anti-scaling materials such as carboxylic acids is considered due to their low risks of environmental pollution. In the present work, the scale inhibition performance of tartaric acid as a green organic material was evaluated. Chemical screening tests, cathodic and anodic voltammetry measurements and electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FESEM), energy-dispersive x-ray and x-ray diffraction, were used for the evaluation of the scale inhibition performance. The results showed that tartaric acid can prevent calcium carbonate precipitation significantly. The hard water solution with 2.0 mM of tartaric acid indicated the highest scale inhibition efficiency (ca. 68%). The voltammetry, EIS and FESEM results verified that tartaric acid can form smooth and homogeneous film on steel surface through formation of Fe(III)-tartrate complexes and retard the local precipitation of calcium carbonate deposits.

  6. Integral-fuel blocks

    International Nuclear Information System (INIS)

    Cunningham, C.; Simpkin, S.D.

    1975-01-01

    A prismatic moderator block is described which has fuel-containing channels and coolant channels disposed parallel to each other and to edge faces of the block. The coolant channels are arranged in rows on an equilateral triangular lattice pattern and the fuel-containing channels are disposed in a regular lattice pattern with one fuel-containing channel between and equidistant from each of the coolant channels in each group of three mutually adjacent coolant channels. The edge faces of the block are parallel to the rows of coolant channels and the channels nearest to each edge face are disposed in two rows parallel thereto, with one of the rows containing only coolant channels and the other row containing only fuel-containing channels. (Official Gazette)

  7. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included...... in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.......5%/2.3% in women, P block was associated with significantly...

  8. Harmonizing human exposure and toxicity characterization

    DEFF Research Database (Denmark)

    Fantke, Peter; Jolliet, O.; McKone, T.E.

    2017-01-01

    The UNEP-SETAC Life Cycle Initiative has launched a project to provide global guidance and build consensus on environmental life cycle impact assessment (LCIA) indicators. Human health effects from exposure to toxic chemicals was selected as impact category due to high relevance of human toxicity...... and harmonizing human toxicity characterization in LCIA. Building on initial work for the far-field and indoor air environments, and combining it with latest work on near-field consumer and occupational exposure assessment, dose-response and severity data, we aim at providing revised guidance on the development...... and use of impact factors for toxic chemicals. We propose to couple fate processes in consumer and occupational environments with existing environmental compartments and processes via a consistent and mass balance-based set of transfer fractions to quantify overall aggregated exposure to toxic substances...

  9. ["Habitual" left branch block alternating with 2 "disguised" bracnch block].

    Science.gov (United States)

    Lévy, S; Jullien, G; Mathieu, P; Mostefa, S; Gérard, R

    1976-10-01

    Two cases of alternating left bundle branch block and "masquerading block" (with left bundle branch morphology in the stnadard leads and right bundle branch block morphology in the precordial leads) were studied by serial tracings and his bundle electrocardiography. In case 1 "the masquerading" block was associated with a first degree AV block related to a prolongation of HV interval. This case is to our knowledge the first cas of alternating bundle branch block in which his bundle activity was recorded in man. In case 2, the patient had atrial fibrilation and His bundle recordings were performed while differents degrees of left bundle branch block were present: The mechanism of the alternation and the concept of "masquerading" block are discussed. It is suggested that this type of block represents a right bundle branch block associated with severe lesions of the "left system".

  10. (Environmental technology)

    Energy Technology Data Exchange (ETDEWEB)

    Boston, H.L.

    1990-10-12

    The traveler participated in a conference on environmental technology in Paris, sponsored by the US Embassy-Paris, US Environmental Protection Agency (EPA), the French Environmental Ministry, and others. The traveler sat on a panel for environmental aspects of energy technology and made a presentation on the potential contributions of Oak Ridge National Laboratory (ORNL) to a planned French-American Environmental Technologies Institute in Chattanooga, Tennessee, and Evry, France. This institute would provide opportunities for international cooperation on environmental issues and technology transfer related to environmental protection, monitoring, and restoration at US Department of Energy (DOE) facilities. The traveler also attended the Fourth International Conference on Environmental Contamination in Barcelona. Conference topics included environmental chemistry, land disposal of wastes, treatment of toxic wastes, micropollutants, trace organics, artificial radionuclides in the environment, and the use biomonitoring and biosystems for environmental assessment. The traveler presented a paper on The Fate of Radionuclides in Sewage Sludge Applied to Land.'' Those findings corresponded well with results from studies addressing the fate of fallout radionuclides from the Chernobyl nuclear accident. There was an exchange of new information on a number of topics of interest to DOE waste management and environmental restoration needs.

  11. E-Block: A Tangible Programming Tool with Graphical Blocks

    OpenAIRE

    Danli Wang; Yang Zhang; Shengyong Chen

    2013-01-01

    This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transfer...

  12. Toxicity of environmental chemicals and their mixtures to selected aquatic organisms. Behaviour, development and biochemistry; Toxizitaet von Umweltchemikalien und deren Mischungen auf ausgewaehlte aquatische Organismen. Verhalten, Entwicklung und Biochemie

    Energy Technology Data Exchange (ETDEWEB)

    Kienle, Cornelia

    2009-04-28

    In this work, the effects of various single substances (pesticides and metals) as well as binary mixtures of them on zebrafish (Danio rerio) embryos and larvae were assessed on biochemical, developmental, and organism levels. The influence of oxygen depletion on the toxicity of substances was included as an additional interacting factor. To analyse complex interactions, the predator-prey behaviour between zebrafish and chironomid larvae (Chironomus riparius) was investigated. Another aspect of this work were studies on complex mixtures of hydrocarbons such as the water accommodated fraction of crude oil, and their effects on the behaviour of marine amphipods (Corophium volutator), as well as semi-field experiments with freshwater amphipods (Gammarus pulex). My investigations showed that effects of various substances in environmentally relevant concentration ranges are exerted on different levels of biological organisation, both in amphipods and fish. It could be shown that abiotic parameters modify the effects of pollutants. When investigating mixtures of substances with similar or different modes of action, additivity occurred in the majority of cases which usually were consistent for all investigated parameters (enzyme activity, locomotor activity, developmental impairment, mortality). Effects of the neurotoxic insecticide chlorpyrifos on the interactions between fish and chironomids could be detected in environmentally relevant concentration ranges. The effects of the water accommodated fraction of crude oil which represents a great risk for aquatic organisms in costal habitats were displayed by alterations in the behaviour of the marine amphipod Corophium volutator. For a continuous monitoring of water quality in monitoring stations, the resident amphipod Gammarus pulex proved to be a suitable and relevant test organism, as it responds sensitive to complex mixtures of pollutants in surface waters. In summary, behavioural parameters proved to be integrative

  13. Linoleum Block Printing Revisited.

    Science.gov (United States)

    Chetelat, Frank J.

    1980-01-01

    The author discusses practical considerations of teaching linoleum block printing in the elementary grades (tool use, materials, motivation) and outlines a sequence of design concepts in this area for the primary, intermediate and junior high grades. A short list of books and audiovisual aids is appended. (SJL)

  14. Spice Blocks Melanoma Growth

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Curcumin, the pungent yellow spice found in both turmeric and curry powders, blocks a key biological pathway needed for development of melanoma and other cancers, according to a study that appears in the journal Cancer. Researchers from The University of Texas M. D. Anderson Cancer Center demonstrate how curcumin stops laboratory strains of…

  15. Los tóxicos ambientales y su impacto en la salud de los niños Environmental toxics and their impact on the child´s health

    Directory of Open Access Journals (Sweden)

    Roberto Zayas Mujica

    2007-06-01

    Full Text Available La relación entre los seres humanos y el ambiente ha variado desde los tiempos remotos hasta la actualidad, y se ha hecho crítica a partir de la segunda mitad del siglo XX. La niñez es el grupo más vulnerable, a causa de su inmadurez anatomofisiológica y su dependencia psicosocial. La contaminación del aire y del agua, las emisiones químicas, el agotamiento del ozono y las consecuencias del cambio climático son los principales problemas relacionados con la salud. Los pediatras deben estar plenamente informados al respecto, puesto que los niños tienen una especial sensibilidad, vulnerabilidad y, en algunos casos, una oportuna capacidad de recuperación ante la acción de diferentes tóxicos ambientales. Nos propusimos revisar en diferentes bases de datos los planteamientos más recientes sobre los efectos de diferentes contaminantes ambientales que amenazan la salud y el desarrollo futuro de los niños.The relationship between human beings and the environment has changed from ancient times to the present, being more critical since the second half of the 20th century. Children are the most vulnerable group due to their anatomic and physiological immaturity and psychosocial dependence. Air and water pollution, chemical emissions, ozone depletion and the consequences of climate change are the main problems related to it. Pediatricians should be duly informed about it because children have special sensitivity, vulnerability and, in some cases, timely recovery capability in the face of the action by different environmental toxics. We intended to review in a number of databases the most recent statements on the effects of various environmental pollutants that threaten health and future development of children.

  16. Toxicity of tritium

    International Nuclear Information System (INIS)

    Dobson, R.L.

    1979-01-01

    Among radionuclides of importance in atomic energy, 3 H has relatively low toxicity. The main health and environmental worry is the possibility that significant biological effects may follow from protracted exposure to low concentrations in water. To examine this possible hazard and measure toxicity at low tritium concentrations, chronic exposure studies were done on mice and monkeys. During vulnerable developmental periods animals were exposed to 3 HOH, and mice were exposed also to 60 Co gamma irradiation and energy-related chemical agents. The biological endpoint measured was the irreversible loss of female germ cells. Effects from tritium were observed at surprisingly low concentrations where 3 H was found more damaging than previously thought. Comparisons between tritium and gamma radiation showed the relative biological effectiveness (RBE) to be greater than 1 and to reach approximately 3 at very low exposures. For perspective, other comparisons were made: between radiation and chemical agents, which revealed parallels in action on germ cells, and between pre- and postnatal exposure, which warn of possible special hazard to the fetus from both classes of energy-related byproducts

  17. Thallium toxicity in humans.

    Science.gov (United States)

    Cvjetko, Petra; Cvjetko, Ivan; Pavlica, Mirjana

    2010-03-01

    Thallium is a naturally occurring trace element, widely distributed in the earth's crust, but at very low concentrations. It does not have a known biological use and does not appear to be an essential element for life. It has been considered one of the most toxic heavy metals.Occasionally, there are reports on thallium poisoning as results of suicide or murder attempt or accident. The main threat to humans is through occupational exposure, environmental contamination, and accumulation in food, mainly in vegetables grown on contaminated soil. Increasing use in emerging new technologies and demanding high-tech industry constantly raise concern about exposure risk to all living organisms. Thallium is considered a cumulative poison that can cause adverse health effects and degenerative changes in many organs. The effects are the most severe in the nervous system. The exact mechanism of thallium toxicity still remains unknown, although impaired glutathione metabolism, oxidative stress, and disruption of potassium-regulated homeostasis may play a role. The lack of data about mutagenic, carcinogenic, or teratogenic effects of thallium compounds in humans calls for further research.

  18. The Acute Toxicity of Major Ion Salts to Ceriodaphnia dubia. III. Mathematical models for mixture toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset concerns the development of models for describing the acute toxicity of major ions to Ceriodaphnia dubia using data from single salt tests and binary...

  19. Environmental biochemistry of chromium.

    Science.gov (United States)

    Losi, M E; Amrhein, C; Frankenberger, W T

    1994-01-01

    Chromium is a d-block transitional element with many industrial uses. It occurs naturally in various crustal materials and is discharged to the environment as industrial waste. Although it can occur in a number of oxidation states, only 3+ and 6+ are found in environmental systems. The environmental behavior of Cr is largely a function of its oxidation state. Hexavalent Cr compounds (mainly chromates and dichromates) are considered toxic to a variety of terrestrial and aquatic organisms and are mobile in soil/water systems, much more so than trivalent Cr compounds. This is largely because of differing chemical properties: Hexavalent Cr compounds are strong oxidizers and highly soluble, while trivalent Cr compounds tend to form relatively inert precipitates at near-neutral pH. The trivalent state is generally considered to be the stable form in equilibrium with most soil/water systems. A diagram of the Cr cycle in soils and water is given in Fig. 6 (Bartlett 1991). This illustration provides a summary of environmentally relevant reactions. Beginning with hexavalent Cr that is released into the environment as industrial waste, there are a number of possible fates, including pollution of soil and surface water and leaching into groundwater, where it may remain stable and, in turn, can be taken up by plants or animals, and adsorption/precipitation, involving soil colloids and/or organic matter. Herein lies much of the environmental concern associated with the hexavalent form. A portion of the Cr(VI) will be reduced to the trivalent form by inorganic electron donors, such as Fe2+ and S2-, or by bioprocesses involving organic matter. Following this conversion, Cr3+ can be expected to precipitate as oxides and hydroxides or to form complexes with numerous ligands. This fraction includes a vast majority of global Cr reserves. Soluble Cr3+ complexes, such as those formed with citrate, can undergo oxidation when they come in contact with manganese dioxide, thus reforming

  20. Classification of baseline toxicants for QSAR predictions to replace fish acute toxicity studies.

    Science.gov (United States)

    Nendza, Monika; Müller, Martin; Wenzel, Andrea

    2017-03-22

    Fish acute toxicity studies are required for environmental hazard and risk assessment of chemicals by national and international legislations such as REACH, the regulations of plant protection products and biocidal products, or the GHS (globally harmonised system) for classification and labelling of chemicals. Alternative methods like QSARs (quantitative structure-activity relationships) can replace many ecotoxicity tests. However, complete substitution of in vivo animal tests by in silico methods may not be realistic. For the so-called baseline toxicants, it is possible to predict the fish acute toxicity with sufficient accuracy from log K ow and, hence, valid QSARs can replace in vivo testing. In contrast, excess toxicants and chemicals not reliably classified as baseline toxicants require further in silico, in vitro or in vivo assessments. Thus, the critical task is to discriminate between baseline and excess toxicants. For fish acute toxicity, we derived a scheme based on structural alerts and physicochemical property thresholds to classify chemicals as either baseline toxicants (=predictable by QSARs) or as potential excess toxicants (=not predictable by baseline QSARs). The step-wise approach identifies baseline toxicants (true negatives) in a precautionary way to avoid false negative predictions. Therefore, a certain fraction of false positives can be tolerated, i.e. baseline toxicants without specific effects that may be tested instead of predicted. Application of the classification scheme to a new heterogeneous dataset for diverse fish species results in 40% baseline toxicants, 24% excess toxicants and 36% compounds not classified. Thus, we can conclude that replacing about half of the fish acute toxicity tests by QSAR predictions is realistic to be achieved in the short-term. The long-term goals are classification criteria also for further groups of toxicants and to replace as many in vivo fish acute toxicity tests as possible with valid QSAR

  1. Arterial and venous plasma levels of bupivacaine following peripheral nerve blocks.

    Science.gov (United States)

    Moore, D C; Mather, L E; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G

    1976-01-01

    Mean arterial plasma (MAP) and peripheral mean venous plasma (MVP) levels of bupivacaine were ascertained in 3 groups of 10 patients each for: (1) intercostal nerve block, 400 mg; (2) block of the sciatic, femoral, and lateral femoral cutaneous nerves, with or without block of the obturator nerve, 400 mg; and (3) supraclavicular brachial plexus block, 300 mg. MAP levels were consistently higher than simultaneously sampled MVP levels, the highest levels occurring from bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine has a much wider margin of safety in humans than is now stated.

  2. Abdominal wall blocks in adults

    DEFF Research Database (Denmark)

    Børglum, Jens; Gögenür, Ismail; Bendtsen, Thomas F

    2016-01-01

    been introduced with success. Future research should also investigate the effect of specific abdominal wall blocks on neuroendocrine and inflammatory stress response after surgery.  Summary USG abdominal wall blocks in adults are commonplace techniques today. Most abdominal wall blocks are assigned......Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.......  Recent findings Ultrasound guidance is now considered the golden standard for abdominal wall blocks in adults, even though some landmark-based blocks are still being investigated. The efficiency of USG transversus abdominis plane blocks in relation to many surgical procedures involving the abdominal wall...

  3. SNUPPS power block engineering

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C A [Bechtel Power Corp., San Francisco, Calif. (USA)

    1975-11-01

    The Standard Power Block is based on a modular concept and consists of the following: turbine building, auxiliary building, fuel building, control building, radwaste building, diesel generators building, and outside storage tanks and transformers. Each power block unit includes a Westinghouse pressurized water reactor and has a thermal power rating of 3425 MW(t). The corresponding General Electric turbine generator net electrical output is 1188 MW(e). This standardization approach results in not only a reduction in the costs of engineering, licensing, procurement, and project planning, but should also result in additional savings by the application of experience gained in the construction of the first unit to the following units and early input of construction data to design.

  4. Air toxics research in Finland

    International Nuclear Information System (INIS)

    Hahkala, M.

    1994-01-01

    Air toxics research in Finland has developed rapidly in recent years. Though they have no enormous environmental problems in Finland, the author feels that they have to increase their knowledge of more efficient energy production and control technology. Enormous emission sources are around them, but there are also huge markets for know-how and technology in the energy sector. Two Finnish national research programs will ensure the continuity of the development efforts concerning combustion technology and environmental aspects at both theoretical and practical levels

  5. Methylmercury-induced toxicity is mediated by enhanced intracellular calcium through activation of phosphatidylcholine-specific phospholipase C

    International Nuclear Information System (INIS)

    Kang, Mi Sun; Jeong, Ju Yeon; Seo, Ji Heui; Jeon, Hyung Jun; Jung, Kwang Mook; Chin, Mi-Reyoung; Moon, Chang-Kiu; Bonventre, Joseph V.; Jung, Sung Yun; Kim, Dae Kyong

    2006-01-01

    Methylmercury (MeHg) is a ubiquitous environmental toxicant to which humans can be exposed by ingestion of contaminated food. MeHg has been suggested to exert its toxicity through its high reactivity to thiols, generation of arachidonic acid and reactive oxygen species (ROS), and elevation of free intracellular Ca 2+ levels ([Ca 2+ ] i ). However, the precise mechanism has not been fully defined. Here we show that phosphatidylcholine-specific phospholipase C (PC-PLC) is a critical pathway for MeHg-induced toxicity in MDCK cells. D609, an inhibitor of PC-PLC, significantly reversed the toxicity in a time- and dose-dependent manner with concomitant inhibition of the diacylglycerol (DAG) generation and the phosphatidylcholine (PC)-breakdown. MeHg activated the group IV cytosolic phospholipase A 2 (cPLA 2 ) and acidic form of sphingomyelinase (A-SMase) downstream of PC-PLC, but these enzymes as well as protein kinase C (PKC) were not linked to the toxicity by MeHg. Furthermore, MeHg produced ROS, which did not affect the toxicity. Addition of EGTA to culture media resulted in partial decrease of [Ca 2+ ] i and partially blocked the toxicity. In contrast, when the cells were treated with MeHg in the presence of Ca 2+ in the culture media, D609 completely prevented cell death with parallel decrease in [Ca 2+ ] i . Our results demonstrated that MeHg-induced toxicity was linked to elevation of [Ca 2+ ] i through activation of PC-PLC, but not attributable to the signaling pathways such as cPLA 2 , A-SMase, and PKC, or to the generation of ROS

  6. Change Around the Block?

    Science.gov (United States)

    Berlin, Joey

    2017-04-01

    Proponents of a block grant or per-capita cap trumpet them as vehicles for the federal government to give the states a capped amount of funding for Medicaid that legislatures would effectively distribute how they see fit. Questions abound as to what capped Medicaid funding would look like, and what effect it would have on the current Medicaid-eligible population, covered services, and physician payments.

  7. SUPERFICIAL CERVICAL PLEXUS BLOCK

    Directory of Open Access Journals (Sweden)

    Komang Mega Puspadisari

    2014-01-01

    Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

  8. E-Block: A Tangible Programming Tool with Graphical Blocks

    Directory of Open Access Journals (Sweden)

    Danli Wang

    2013-01-01

    Full Text Available This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transferred to computer by microcomputers and then translated into semantic information. The system applies wireless and infrared technologies and provides user with feedbacks on both screen and programming blocks. Preliminary user studies using observation and user interview methods are shown for E-Block's prototype. The test results prove that E-Block is attractive to children and easy to learn and use. The project also highlights potential advantages of using single chip microcomputer (SCM technology to develop tangible programming tools for children.

  9. The Effects of Temperature and Hydrostatic Pressure on Metal Toxicity: Insights into Toxicity in the Deep Sea.

    Science.gov (United States)

    Brown, Alastair; Thatje, Sven; Hauton, Chris

    2017-09-05

    Mineral prospecting in the deep sea is increasing, promoting concern regarding potential ecotoxicological impacts on deep-sea fauna. Technological difficulties in assessing toxicity in deep-sea species has promoted interest in developing shallow-water ecotoxicological proxy species. However, it is unclear how the low temperature and high hydrostatic pressure prevalent in the deep sea affect toxicity, and whether adaptation to deep-sea environmental conditions moderates any effects of these factors. To address these uncertainties we assessed the effects of temperature and hydrostatic pressure on lethal and sublethal (respiration rate, antioxidant enzyme activity) toxicity in acute (96 h) copper and cadmium exposures, using the shallow-water ecophysiological model organism Palaemon varians. Low temperature reduced toxicity in both metals, but reduced cadmium toxicity significantly more. In contrast, elevated hydrostatic pressure increased copper toxicity, but did not affect cadmium toxicity. The synergistic interaction between copper and cadmium was not affected by low temperature, but high hydrostatic pressure significantly enhanced the synergism. Differential environmental effects on toxicity suggest different mechanisms of action for copper and cadmium, and highlight that mechanistic understanding of toxicity is fundamental to predicting environmental effects on toxicity. Although results infer that sensitivity to toxicants differs across biogeographic ranges, shallow-water species may be suitable ecotoxicological proxies for deep-sea species, dependent on adaptation to habitats with similar environmental variability.

  10. Environmental physiology

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Summaries of research projects conducted during 1978 and 1979 are presented. Subject areas include: the effects of environmental pollutants on homeostasis of the hematopoietic system; pollutant effects on steroid metabolism; pollutant effects on pulmonary macrophages; effects of toxic gases on lung cells; the development of immunological methods for assessing lung damage at the cellular level; the response of erythropoietin concentration to various physiological changes; and the study of actinide metabolism in monkey skeletons

  11. Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

    2014-01-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

  12. Block and sub-block boundary strengthening in lath martensite

    NARCIS (Netherlands)

    Du, C.; Hoefnagels, J.P.M.; Vaes, R.; Geers, M.G.D.

    2016-01-01

    Well-defined uniaxial micro-tensile tests were performed on lath martensite single block specimens and multi-block specimens with different number of block boundaries parallel to the loading direction. Detailed slip trace analyses consistently revealed that in the {110}<111> slip system with the

  13. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  14. Atrioventricular block, ECG tracing (image)

    Science.gov (United States)

    ... an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the ... wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).

  15. 78 FR 20032 - Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-04-03

    ...-Ethylene-Propylene Block Copolymer; Tolerance Exemption AGENCY: Environmental Protection Agency (EPA... for residues of styrene-ethylene-propylene block copolymer (CAS Reg. No. 108388-87-0) when used as an...-ethylene-propylene block copolymer on food or feed commodities. DATES: This regulation is effective April 3...

  16. Fermion-scalar conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Iliesiu, Luca [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Kos, Filip [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); Poland, David [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Simmons-Duffin, David [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Yacoby, Ran [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States)

    2016-04-13

    We compute the conformal blocks associated with scalar-scalar-fermion-fermion 4-point functions in 3D CFTs. Together with the known scalar conformal blocks, our result completes the task of determining the so-called ‘seed blocks’ in three dimensions. Conformal blocks associated with 4-point functions of operators with arbitrary spins can now be determined from these seed blocks by using known differential operators.

  17. EnviroAtlas - New York, NY - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 6,378 block groups in New York City, New York. Carbon attributes, temperature...

  18. EnviroAtlas - Green Bay, WI - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 155 block groups in Green Bay, Wisconsin. Carbon attributes, temperature reduction,...

  19. EnviroAtlas - Des Moines, IA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 312 block groups in Des Moines, IA. Carbon attributes, temperature reduction,...

  20. EnviroAtlas - Minneapolis/St. Paul, MN - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 1,772 block groups in Minneapolis/St. Paul, Minnesota. Carbon attributes, temperature...

  1. EnviroAtlas - New Bedford, MA - Ecosystem Services by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset presents environmental benefits of the urban forest in 128 block group in New Bedford, Massachusetts. Carbon attributes, temperature...

  2. Powder wastes confinement block and manufacturing process of this block

    International Nuclear Information System (INIS)

    Dagot, L.; Brunel, G.

    1996-01-01

    This invention concerns a powder wastes containment block and a manufacturing process of this block. In this block, the waste powder is encapsulated in a thermo hardening polymer as for example an epoxy resin, the encapsulated resin being spread into cement. This block can contain between 45 and 55% in mass of wastes, between 18 and 36% in mass of polymer and between 14 and 32% in mass of cement. Such a containment block can be used for the radioactive wastes storage. (O.M.). 4 refs

  3. Toxicities of selected substances to freshwater biota

    Energy Technology Data Exchange (ETDEWEB)

    Hohreiter, D.W.

    1980-05-01

    The amount of data available concerning the toxicity of various substances to freshwater biota is so large that it is difficult to use in a practical situation, such as environmental impact assessment. In this document, summary tables are presented showing acute and/or chronic toxicity of selected substances for various groups of aquatic biota. Each entry is referenced to its original source so that details concerning experimental conditions may be consulted. In addition, general information concerning factors modifying toxicity, synergisms, evidence of bioaccumulation, and water quality standards and criteria for the selected substances is given. The final table is a general toxicity table designed to provide an easily accessible and general indication of toxicity of selected substances in aquatic systems.

  4. Building Curriculum during Block Play

    Science.gov (United States)

    Andrews, Nicole

    2015-01-01

    Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

  5. Isotope heating block

    International Nuclear Information System (INIS)

    Wenk, E.

    1976-01-01

    A suggestion is made not to lead the separated nuclear 'waste' from spent nuclear fuel elements directly to end storage, but to make use of the heat produced from the remaining radiation, e.g. for seawater desalination. According to the invention, the activated fission products are to be processed, e.g. by calcination or vitrification, so that one can handle them. They should then be arranged in layers alternately with plate-shaped heat conducting pipes to form a homogeneous block; the heat absorbed by the thermal plates should be further passed on to evaporators or heat exchangers. (UWI) [de

  6. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  7. Simple and sensitive determination of atrazine and its toxic metabolites in environmental water by carboxyl modified polyacrylonitrile nanofibers mat-based solid-phase extraction coupled with liquid chromatography-diode array detection.

    Science.gov (United States)

    Cao, Weixin; Yang, Biyi; Qi, Feifei; Qian, Liangliang; Li, Jian; Lu, Lingeng; Xu, Qian

    2017-03-31

    Carboxyl modified polyacrylonitrile nanofibers mat (COOH-PAN NFsM) was prepared as a novel solid-phase extraction (SPE) adsorbent for the rapid and effective extraction of atrazine (ATZ) and its toxic metabolites deisopropylatrazine (DIA) and deethylatrazine (DEA) from environmental water samples. Without any pre-treatment but only with the simple filter, water samples passed through pre-conditioned COOH-PAN NFsM, which integrated extraction, purification and concentration into one single step, and the eluent was directly analyzed by high performance liquid chromatography-diode array detection (HPLC-DAD). Under the optimized conditions, the target analytes in 10mL of water sample could be completely extracted by only 4mg of COOH-PAN NFsM, and easily eluted using 400μL of methanol, indicating a high efficiency in both adsorption and desorption. Satisfactory linearity was achieved in the range of 0.4-40.0ngmL -1 for DIA, and 0.3-40.0ngmL -1 for DEA and ATZ. The limit of detection (LODs) were 0.12, 0.09 and 0.09ngmL -1 for DIA, DEA and ATZ, respectively. The recoveries ranged from 81.35 to 120.32%, with the intra-day and inter-day relative standard deviations of 4.03-9.81% even after the 6-cycle usage of NFsM. And, using just 10mL loading sample, the LOD had already satisfied the demand of surface water quality monitoring levels, revealing the good sensitivity of the proposed method. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Toxicity alarm: Case history

    International Nuclear Information System (INIS)

    Hogan, D.; Retallack, J.

    1993-01-01

    In late fall 1991, the Novacor petrochemical plant near Joffre, Alberta experienced a toxicity alarm, the first since its startup 14 years ago. Fish exposed to a normal toxicity test were stressed within 2 h and showed 100% mortality after 24 h. A history of the events leading up to, during, and after the toxicity alarm is presented. The major effluent sources were three cooling water systems. Although these sources are well characterized, the event causes were not immediately clear. Initial toxic screening indicated that one was very toxic, another moderately toxic, and the third not toxic at all. All three systems utilized the same chemical treatment program to avoid fouling: stabilized phosphates with minor variants. The most toxic of the cooling systems operated at 10-12 cycles, had three chemicals for biocide control, and had three makeup streams. Toxic and nontoxic system characteristics were compared. An in-depth modified toxicity identification and evaluation program was then performed to identify and evaluate the cause of the toxicity alarm for future prevention. The most probable causes of toxicity were identified by elimination. The combination of high numbers of cycles, hydrocarbons in the makeup water, and bromine added as an antifoulant resulted in formation of aromatic bromamines which are capable of causing the toxic condition experienced. 2 tabs

  9. A standard graphite block

    Energy Technology Data Exchange (ETDEWEB)

    Ivkovic, M; Zdravkovic, Z; Sotic, O [Department of Reactor Physics and Dynamics, Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1966-04-15

    A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 {+-}3.1 cm for the following graphite characteristics: density = 1.7 g/cm{sup 3}; boron content = 0.1 ppm; absorption cross section = 3.7 mb.

  10. A standard graphite block

    International Nuclear Information System (INIS)

    Ivkovic, M.; Zdravkovic, Z.; Sotic, O.

    1966-04-01

    A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 ±3.1 cm for the following graphite characteristics: density = 1.7 g/cm 3 ; boron content = 0.1 ppm; absorption cross section = 3.7 mb

  11. Toxic substances handbook

    Science.gov (United States)

    Junod, T. L.

    1979-01-01

    Handbook, published in conjunction with Toxic Substances Alert Program at NASA Lewis Research Center, profiles 187 toxic chemicals in their relatively pure states and include 27 known or suspected carcinogens.

  12. Baltimore Air Toxics Study (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D.A. [Sullivan Environmental Consulting, Inc., Alexandria, VA (United States)

    1996-12-31

    The Baltimore Air Toxics Study is one of the three urban air toxics initiatives funded by EPA to support the development of the national air toxics strategy. As part of this project, the Air Quality Integrated Management System (AIMS) is under development. AIMS is designed to bring together the key components of urban air quality management into an integrated system, including emissions assessment, air quality modeling, and air quality monitoring. Urban area source emissions are computed for a wide range of pollutants and source categories, and are joined with existing point source emissions data. Measured air quality data are used to evaluate the adequacy of the emissions data and model treatments as a function of season, meteorological parameters, and daytime/nighttime conditions. Based on tested model performance, AIMS provides the potential to improve the ability to predict air quality benefits of alternative control options for criteria and toxic air pollutants. This paper describes the methods used to develop AIMS, and provides examples from its application in the Baltimore metropolitan area. The use of AIMS in the future to enhance environmental management of major industrial facilities also will be addressed in the paper.

  13. Evaluation of nano-specific toxicity of zinc oxide, copper oxide, and silver nanoparticles through toxic ratio

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weicheng; Liu, Xiawei; Bao, Shaopan; Xiao, Bangding; Fang, Tao, E-mail: fangt@ihb.ac.cn [Chinese Academy of Sciences, Institute of Hydrobiology (China)

    2016-12-15

    For safety and environmental risk assessments of nanomaterials (NMs) and to provide essential toxicity data, nano-specific toxicities, or excess toxicities, of ZnO, CuO, and Ag nanoparticles (NPs) (20, 20, and 30 nm, respectively) to Escherichia coli and Saccharomyces cerevisiae in short-term (6 h) and long-term (48 h) bioassays were quantified based on a toxic ratio. ZnO NPs exhibited no nano-specific toxicities, reflecting similar toxicities as ZnO bulk particles (BPs) (as well as zinc salt). However, CuO and Ag NPs yielded distinctly nano-specific toxicities when compared with their BPs. According to their nano-specific toxicities, the capability of these NPs in eliciting hazardous effects on humans and the environment was as follows: CuO > Ag > ZnO NPs. Moreover, long-term bioassays were more sensitive to nano-specific toxicity than short-term bioassays. Overall, nano-specific toxicity is a meaningful measurement to evaluate the environmental risk of NPs. The log T{sub e}{sup particle} value is a useful parameter for quantifying NP nano-specific toxicity and enabling comparisons of international toxicological data. Furthermore, this value could be used to determine the environmental risk of NPs.

  14. The wild tapered block bootstrap

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...... of the series first, the applying the standard wild bootstrap for independent and heteroscedastic distrbuted observations to overlapping tapered blocks in an appropriate way. Its perserves the favorable bias and mean squared error properties of the tapered block bootstrap, which is the state-of-the-art block......-order asymptotic validity of the tapered block bootstrap as well as the wild tapered block bootstrap approximation to the actual distribution of the sample mean is also established when data are assumed to satisfy a near epoch dependent condition. The consistency of the bootstrap variance estimator for the sample...

  15. Photovoltaic building blocks

    DEFF Research Database (Denmark)

    Hanberg, Peter Jesper; Jørgensen, Anders Michael

    2014-01-01

    efficiency of about 15% for commercial Silicon solar cells there is still much to gain. DTU Danchip provides research facilities, equipment and expertise for the building blocks that comprises fabricating the efficient solar cell. In order to get more of the sun light into the device we provide thin film......Photovoltaics (PV), better known as solar cells, are now a common day sight on many rooftops in Denmark.The installed capacity of PV systems worldwide is growing exponentially1 and is the third most importantrenewable energy source today. The cost of PV is decreasing fast with ~10%/year but to make...... it directcompetitive with fossil energy sources a further reduction is needed. By increasing the efficiency of the solar cells one gain an advantage through the whole chain of cost. So that per produced Watt of power less material is spent, installation costs are lower, less area is used etc. With an average...

  16. Celiac ganglia block

    International Nuclear Information System (INIS)

    Akinci, Devrim; Akhan, Okan

    2005-01-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation

  17. Atomic Basic Blocks

    Science.gov (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  18. Some Blocks from Heliopolis

    Directory of Open Access Journals (Sweden)

    dr.Nageh Omar

    2005-01-01

    Full Text Available These group of Architectural Fragments have been discovered during Excavations at Souq el – Khamees Site at the end of Mostorod Street in el – Matarya Area by the Supreme Council of Antiquities Mission Season 2003 and none published before . The Site of Excavations is Situated about 500 metres to the west Obelisk of the King Senusert I According to the inscriptions on the block (pl.1.a,fig.1 represents the coronation name of the king Senusret III, the fifth king of the twelfth dynasty within the cartouche .Through This recent discover and his Sphinx statue we Suggest that the king Senusret III built a shrine or Temple at Heliopols which was possibly a part of the great Temple of the universal God of Heliopolis . For block dating to the king Akhenaten and many monuments are discovered in Heliopolis at the same period emphasized that the king Akhenaten built temple for the god Aten in Heliopolis and through Studies about the king Akhenaten, we suggest that the king Akhenaten take his new principles from Heliopolis . The king Ramesses II mentioned from stela which discovered at Manshyt el- Sader, in the second horizontal line that he erected oblesk and some statues at the great Temple in Heliopolis , this recent Discover about Statue of the king Ramesses II emphasized site of excavations perhaps a shrine or open court from temple of the king Ramesses II at the great Temple in Heliopolis For nbt – htpt, we could show that the goddess Hathor take a forward position in Heliopolis and become the Lady of Hetepet in Heliopolis since Eighteenth dynasty at least

  19. Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m{sup 2}). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper.

  20. Photocatalytic pavement blocks. Air purification by pavement blocks. Final results of the research at BRRC

    International Nuclear Information System (INIS)

    2009-01-01

    The use of materials can influence to a large extent the environmental impact of traffic and of road infrastructure. Especially in urban areas, where the risk on smog formation during hot summer days is high, the use of photocatalytic pavement blocks can reduce the air pollution significantly. A project on environmental friendly concrete pavement blocks is conducted at the Belgian Road Research Centre. The use of photocatalytic material in the surface of pavement blocks to obtain air purifying materials is investigated. In contact with light, TiO2 as photocatalyst, is able to reduce the NO and NO2 content in the air, caused by the exhaust of traffic. The efficiency is tested on pavement blocks, but the technique can as well be applied on other road elements (e.g. noise reducing walls, linear elements) or as a coating on new materials or existing structures. At the previous TRA conference in Gotenborgh, Sweden, the principle of photocatalysis was presented. In this paper, emphasis will be put on the final results of the 4-year project obtained in laboratory as well as on site at the Leien of Antwerp (10,000 m 2 ). The results indicate a durable efficiency towards NOx reduction, which is in favour for the diminishing of the risk on ozone formation. However, the precise translation from the laboratory towards the site is still in question. The results obtained during the project are discussed in this paper

  1. 2015 TRI National Analysis: Toxics Release Inventory Releases at Various Summary Levels

    Data.gov (United States)

    U.S. Environmental Protection Agency — The TRI National Analysis is EPA's annual interpretation of TRI data at various summary levels. It highlights how toxic chemical wastes were managed, where toxic...

  2. TOXICITY COMPARISON OF BIOSURFACTANTS AND SYNTHETIC SURFACTANTS USED IN OIL SPILL REMEDIATION TO TWO ESTUARINE SPECIES

    Science.gov (United States)

    The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbially produced surfactants were determined and compared in this s...

  3. 76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Science.gov (United States)

    2011-10-17

    ... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for Hydrogen Sulfide. SUMMARY: EPA is announcing... (EPCRA) section 313 toxic chemical release reporting requirements for hydrogen sulfide (Chemical...

  4. COMPUTER SUPPORT SYSTEMS FOR ESTIMATING CHEMICAL TOXICITY: PRESENT CAPABILITIES AND FUTURE TRENDS

    Science.gov (United States)

    Computer Support Systems for Estimating Chemical Toxicity: Present Capabilities and Future Trends A wide variety of computer-based artificial intelligence (AI) and decision support systems exist currently to aid in the assessment of toxicity for environmental chemicals. T...

  5. The toxicity of plutonium

    International Nuclear Information System (INIS)

    Ramsden, D.; Johns, T.F.

    1977-01-01

    Reference is made to recent publications concerned with the radiotoxicity of inhaled insoluble Pu compounds. The publications are a paper by Thorne and Vennart (Nature 263:555 (1976)), a report entitled 'The Toxicity of Plutonium', (London (HMSO), 1975), and the 'Sixth Report of the Royal Commission on Environmental Pollution', (Cmnd. 6618, London (HMSO), 1976). Thorne and Vennart concluded that the previously accepted value for the maximum permissible annual intake (MPAI) of such compounds may be too high by a factor of about five, and a similar conclusion was reached in the other two publications. It is thought by the present authors that the methods which have been used to suggest new values for the MPAI are unduly pessimistic for high-fired PuO 2 ; calculations have been based on the lung model of ICRP Publication 19 'The Metabolism of Compounds of Plutonium and the Other Actinides', (International Commission of Radiological Protection, 1972). This involves concluding that the risks to bone and liver are comparable to those for lung. This is discussed and it is thought that the previously established idea that the lung is the critical organ remains substantially correct for the case of high-fired PuO 2 . (U.K.)

  6. The Environmental and Molecular Sciences Laboratory project -- Continuous evolution in leadership

    International Nuclear Information System (INIS)

    Knutson, D.E.; McClusky, J.K.

    1994-10-01

    The Environmental and Molecular Sciences Laboratory (EMSL) construction project at Pacific Northwest Laboratory (PNL) in Richland, Washington, is a $230M Major Systems Acquisition for the US Department of Energy (DOE). The completed laboratory will be a national user facility that provides unparalleled capabilities for scientists involved in environmental molecular science research. This project, approved for construction by the Secretary of Energy in October 1993, is underway. The United States is embarking on an environmental cleanup effort that dwarfs previous scientific enterprise. Using current best available technology, the projected costs of cleaning up the tens of thousands of toxic waste sites, including DOE sites, is estimated to exceed one trillion dollars. The present state of scientific knowledge regarding the effects of exogenous chemicals on human biology is very limited. Long term environmental research at the molecular level is needed to resolve the concerns, and form the building blocks for a structure of cost effective process improvement and regulatory reform

  7. The Environmental and Molecular Sciences Laboratory project -- Continuous evolution in leadership

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, D.E.; McClusky, J.K.

    1994-10-01

    The Environmental and Molecular Sciences Laboratory (EMSL) construction project at Pacific Northwest Laboratory (PNL) in Richland, Washington, is a $230M Major Systems Acquisition for the US Department of Energy (DOE). The completed laboratory will be a national user facility that provides unparalleled capabilities for scientists involved in environmental molecular science research. This project, approved for construction by the Secretary of Energy in October 1993, is underway. The United States is embarking on an environmental cleanup effort that dwarfs previous scientific enterprise. Using current best available technology, the projected costs of cleaning up the tens of thousands of toxic waste sites, including DOE sites, is estimated to exceed one trillion dollars. The present state of scientific knowledge regarding the effects of exogenous chemicals on human biology is very limited. Long term environmental research at the molecular level is needed to resolve the concerns, and form the building blocks for a structure of cost effective process improvement and regulatory reform.

  8. Common blocks for ASQS(12

    Directory of Open Access Journals (Sweden)

    Lorenzo Milazzo

    1997-05-01

    Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

  9. Mixture toxicity of wood preservative products in the fish embryo toxicity test.

    Science.gov (United States)

    Coors, Anja; Dobrick, Jan; Möder, Monika; Kehrer, Anja

    2012-06-01

    Wood preservative products are used globally to protect wood from fungal decay and insects. We investigated the aquatic toxicity of five commercial wood preservative products, the biocidal active substances and some formulation additives contained therein, as well as six generic binary mixtures of the active substances in the fish embryo toxicity test (FET). Median lethal concentrations (LC50) of the single substances, the mixtures, and the products were estimated from concentration-response curves and corrected for concentrations measured in the test medium. The comparison of the experimentally observed mixture toxicity with the toxicity predicted by the concept of concentration addition (CA) showed less than twofold deviation for all binary mixtures of the active substances and for three of the biocidal products. A more than 60-fold underestimation of the toxicity of the fourth product by the CA prediction was detected and could be explained fully by the toxicity of one formulation additive, which had been labeled as a hazardous substance. The reason for the 4.6-fold underestimation of toxicity of the fifth product could not be explained unambiguously. Overall, the FET was found to be a suitable screening tool to verify whether the toxicity of formulated wood preservatives can reliably be predicted by CA. Applied as a quick and simple nonanimal screening test, the FET may support approaches of applying component-based mixture toxicity predictions within the environmental risk assessment of biocidal products, which is required according to European regulations. Copyright © 2012 SETAC.

  10. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    DEFF Research Database (Denmark)

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

  11. The block transfer system

    International Nuclear Information System (INIS)

    Bradish, G.J. III; Reid, A.E.

    1986-01-01

    The central instrumentation control and data acquisition (CICADA) computer system is comprised of a functionally distributed hierarchical network of thirteen (13) 32-bit mini-computers that are the heart of the control, monitoring, data collection and data analysis for the tokamak fusion test reactor (TFTR). The CICADA system was designed with the goal of providing complete control, monitoring, and data acquisition for TFTR, which includes the acquisition and storage of 20M points of data within a five-minute shot cycle. It was realized early in the system design that in order to meet this goal an ancillary system would have to be provided to supplement the subsystem CAMAC systems that, due to the relatively slow throughput of the serial highways and the overhead of relaying data to the central facilities within a star network, would not provide the necessary throughput. The authors discuss how the block transfer system provided a means of moving data directly from the CAMAC crate to the application running on the central facility computers

  12. Developmental toxicity of organotin compounds in animals

    Directory of Open Access Journals (Sweden)

    Lijiao eWu

    2014-09-01

    Full Text Available Organotin compounds (OTs have been used as biocides in antifouling paints and agriculture. The IMO introduced a global ban on the use of OTs in antifouling systems in 2001 due to their high toxicity. However, OTs have still been detected in the environment and pose a threat to the ecosystem. Several research groups have summarized the analytical methods, environmental fate, biochemistry, reproductive toxicity and mechanisms of actions of OTs. Here, we reviewed the developmental toxicity of OTs in various organisms such as sea urchin, ascidian, mussel and fish. The differences in sensitivity to OT exposure exist not only in different species but also at different stages in the same species. Though some hypotheses have been proposed to explain the developmental toxicity of OTs, the solid evidences are greatly in need.

  13. DOE contractor's meeting on chemical toxicity

    International Nuclear Information System (INIS)

    1987-01-01

    The Office of Health and Environmental Research (OHER) is required to determine the potential health and environmental effects associated with energy production and use. To ensure appropriate communication among investigators and scientific disciplines that these research studies represent, OHER has sponsored workshops. This document provides a compilation of activities at the Third Annual DOE/OHER Workshop. This year's workshop was broadened to include all OHER activities identified as within the chemical effects area. The workshop consisted of eight sessions entitled Isolation and Detection of Toxic chemicals; Adduct Formation and Repair; Chemical Toxicity (Posters); Metabolism and Genotoxicity; Inhalation Toxicology; Gene Regulation; Metals Toxicity; and Biological Mechanisms. This document contains abstracts of the information presented by session

  14. Toxic substances alert program

    Science.gov (United States)

    Junod, T. L.

    1978-01-01

    A toxicity profile is provided, of 187 toxic substances procured by NASA Lewis Research Center during a 3 1/2 year period, including 27 known or suspected carcinogens. The goal of the program is to assure that the center's health and safety personnel are aware of the procurement and use of toxic substances and to alert and inform the users of these materials as to the toxic characteristics and the control measures needed to ensure their safe use. The program also provides a continuing record of the toxic substances procured, who procured them, what other toxic substances the user has obtained in the past, and where similar materials have been used elsewhere at the center.

  15. 40 CFR 129.4 - Toxic pollutants.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS TOXIC POLLUTANT EFFLUENT... material consisting of technical grade chlorinated camphene having the approximate formula of C10 H10 Cl8... molecule which has been chlorinated to varying degrees. [42 FR 2613, Jan. 12, 1977, as amended at 42 FR...

  16. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  17. Writing Blocks and Tacit Knowledge.

    Science.gov (United States)

    Boice, Robert

    1993-01-01

    A review of the literature on writing block looks at two kinds: inability to write in a timely, fluent fashion, and reluctance by academicians to assist others in writing. Obstacles to fluent writing are outlined, four historical trends in treating blocks are discussed, and implications are examined. (MSE)

  18. Block storage subsystem performance analysis

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  19. Region 9 Census Block 2010

    Science.gov (United States)

    Geography:The TIGER Line Files are feature classes and related database files (.) that are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census Blocks are statistical areas bounded on all sides by visible features, such as streets, roads, streams, and railroad tracks, and/or by non visible boundaries such as city, town, township, and county limits, and short line-of-sight extensions of streets and roads. Census blocks are relatively small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas are often large and irregular and may even be many square miles in area. A common misunderstanding is that data users think census blocks are used geographically to build all other census geographic areas, rather all other census geographic areas are updated and then used as the primary constraints, along with roads and water features, to delineate the tabulation blocks. As a result, all 2010 Census blocks nest within every other 2010 Census geographic area, so that Census Bureau statistical data can be tabulated at the block level and aggregated up t

  20. Select toxic metals status of pregnant women with history of ...

    African Journals Online (AJOL)

    Toxic metals are part of the most important groups of environmental pollutants that can bind to vital cellular components and interfere with their functions via inhalation, foods, water etc. The serum levels of toxic metals (lead, mercury, cadmium and arsenic) in pregnant women with history of pregnancy complications, ...

  1. The Structure of Algal Population in the Presence of Toxicants

    Science.gov (United States)

    Ipatova, Valentina; Prokhotskaya, Valeria; Dmitrieva, Aida

    Algal bioassays are routinely employed as part of a battery of toxicity tests to assess the environmental impacts of contaminants on aquatic ecosystems. This estimation is an essential component of the ecological risk assessment.

  2. Distribution, exposure pathways, sources and toxicity of nonylphenol ...

    African Journals Online (AJOL)

    Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue ... of their toxicity, oestrogenic properties and widespread contamination. ... to provide better understanding of these emerging environmental contaminants.

  3. Monitoring of essential and toxic metals in imported herbal teas ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... Teas are the most consumed beverage worldwide after water, and its consumption ... Key words: Herbal teas, food safety, health risk assessment, THQ, EDI, HI, toxic metals ...

  4. Development and In Vitro Toxicity Evaluation of Alternative Sustainable Nanomaterials

    Science.gov (United States)

    Novel nanomaterial types are rapidly being developed for the value they may add to consumer products without sufficient evaluation of implications for human health, toxicity, environmental impact and long-term sustainability. Nanomaterials made of metals, semiconductors and vario...

  5. Plant responses to metal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Briat, J.F. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie moleculaire des plantes, CNRS, URA 2133; Lebrun, M. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie vegetale appliquee

    1999-01-01

    Increased metal concentration in the soils, up to toxic levels, is becoming an important environmental problem. Safety rule evolution will require solutions in order to cope with food safety rules, and to freeze metal leakage from heavily metal-poisoned soils, such as those from industrial fallows. In this context, plants could serve to develop bio-assays in order to promote new standards, more realistic than the mass of a given metal per kg of soil, that does not consider the metal bio-disponibility. Plants could also be used for phyto-extraction and/or phyto-stabilization. To reach these objectives, a genetic approach could be useful to generate metal-tolerant plants with enough biomass. In this work is more particularly studied the plant responses to metal toxicity. Metal toxicity for living organisms involves oxidative and /or genotoxic mechanisms. Plant protection against metal toxicity occurs, at least in part, through control of root metal uptake and of long distance metal transport. Inside cells, proteins such as ferritins and metallothioneins, and glutathione-derived peptides named phyto-chelatins, participate in excess metal storage and detoxification. Low molecular weight organic molecules, mainly organic acids and amino acids and their derivatives, also play an important role in plant metal homeostasis. When these systems are overloaded, oxidative stress defense mechanisms are activated. Molecular and cellular knowledge of these processes will be necessary to improve plant metal resistance. Occurrence of naturally tolerant plants which hyper accumulate metals provides helpful tools for this research. (authors) 130 refs.

  6. Molecular basis of cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Nath, R; Prasad, R; Palinal, V K; Chopra, R K

    1984-01-01

    Cadmium has been shown to manifest its toxicity in human and animals by mainly accumulating in almost all of the organs. The kidney is the main target organ where it is concentrated mainly in the cortex. Environmental exposure of cadmium occurs via food, occupational industries, terrestrial and aquatic ecosystem. At molecular level, cadmium interferes with the utilization of essential metals e.g. Ca, Zn, Se, Cr and Fe and deficiencies of these essential metals including protein and vitamins, exaggerate cadmium toxicity, due to its increased absorption through the gut and greater retention in different organs as metallothionein (Cd-Mt). Cadmium transport, across the intestinal and renal brush border membrane vesicles, is carrier mediated and it competes with zinc and calcium. It has been postulated that cadmium shares the same transport system. Cadmium inhibits protein synthesis, carbohydrate metabolism and drug metabolizing enzymes in liver of animals. Chronic environmental exposure of cadmium produces hypertension in experimental animals. Functional changes accompanying cadmium nephropathy include low molecular weight proteinuria which is of tubular origin associated with excess excretion of proteins such as beta 2 microglobulin, metallothionein and high molecular weight proteinuria of glomerular origin (excretion of proteins such as albumin IgG, transferrin etc.). Recent data has shown that metallothionein is more nephrotoxic to animals. Cadmium is also toxic to central nervous system. It causes an alterations of cellular functions in lungs. Cadmium affects both humoral and cell mediated immune response in animals. Cadmium induces metallothionein in liver and kidney but under certain nutritional deficiencies like protein-calorie malnutrition and calcium deficiency, enhanced induction and greater accumulation of cadmium metallothionein has been observed.

  7. Females and Toxic Leadership

    Science.gov (United States)

    2012-12-14

    labeled as toxic, can he or she be rehabilitated?; Are there leadership styles that can be promoted to combat toxic leadership?; and Are the senior...examines leadership styles that are favorable for female leaders, and offers Transformational/Adaptive leadership as a style promising rehabilitative tools

  8. Mechanisms of Phosphine Toxicity

    Directory of Open Access Journals (Sweden)

    Nisa S. Nath

    2011-01-01

    Full Text Available Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3, the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N and arsenic (As, which also produce toxic hydrides, namely, NH3 and AsH3. The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity.

  9. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  10. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Sobko, Evgeny [Stockholm Univ. (Sweden); Nordita, Stockholm (Sweden); Isachenkov, Mikhail [Weizmann Institute of Science, Rehovoth (Israel). Dept. of Particle Physics and Astrophysics

    2016-12-07

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  11. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sobko, Evgeny [Nordita and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Isachenkov, Mikhail [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel)

    2017-03-15

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  12. Developing Key Parameters for Green Performance of Partition Wall Blocks

    Directory of Open Access Journals (Sweden)

    Goh Cheng Siew

    2016-01-01

    Full Text Available To promote sustainable construction, it is important to consider green performance of construction materials throughout the life cycle. Selecting inappropriate materials could not only affect the functional performance but also preclude the achievement of green building performance as a whole. Green performance of construction materials has therefore been one of the primary considerations of green building assessment systems. Using partition wall blocks as an example, this paper examines green performance of building materials primarily from the cradle to gate boundaries. Nine key parameters are proposed for the green performance of partition wall blocks. Apart from environmental features, technical performance of partition wall blocks is also taken into consideration since it is the determinant of the lifecycle performance. This paper offers a roadmap to decision makers to make environmentally responsible choices for their materials of internal walls and partitions, and hence provides a potential sustainable solution for green buildings.

  13. Applicable international environmental impact assessment laws for ...

    African Journals Online (AJOL)

    Lawrence Hart

    1971-05-28

    May 28, 1971 ... appraise selected International Environmental laws and the Nigerian Environmental Impact Assessment methodology ... maze of pipelines, delivery lines, flow lines, canals and .... Toxic Materials and international waterways.

  14. Risk-Screening Environmental Indicators (RSEI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA’s Risk-Screening Environmental Indicators (RSEI) is a geographically-based model that helps policy makers and communities explore data on releases of toxic...

  15. Rolling block mazes are PSPACE-complete

    NARCIS (Netherlands)

    Buchin, K.; Buchin, M.

    2012-01-01

    In a rolling block maze, one or more blocks lie on a rectangular board with square cells. In most mazes, the blocks have size k × m × n where k, m, n are integers that determine the size of the block in terms of units of the size of the board cells. The task of a rolling block maze is to roll a

  16. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  17. Recursion Relations for Conformal Blocks

    CERN Document Server

    Penedones, João; Yamazaki, Masahito

    2016-09-12

    In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

  18. Defying gravity using Jenga™ blocks

    Science.gov (United States)

    Tan, Yin-Soo; Yap, Kueh-Chin

    2007-11-01

    This paper describes how Jenga™ blocks can be used to demonstrate the physics of an overhanging tower that appears to defy gravity. We also propose ideas for how this demonstration can be adapted for the A-level physics curriculum.

  19. Toxicity identification evaluations of produced-water effluents

    International Nuclear Information System (INIS)

    Sauer, T.C.; Costa, H.J.; Brown, J.S.; Ward, T.J.

    1997-01-01

    Toxicity identification evaluations (TIEs) were performed on 14 produced-water (PW) samples of various salinities from inland and offshore oil- and gas-production facilities operated by different companies in Wyoming, Texas, California, and Louisiana (USA) to evaluate the efficacy of TIE procedures in determining potential toxicants in PW effluents. The research involved acute (24- and 48-h) freshwater and marine toxicity tests on whole PW and PW fractions generated by standard US Environmental Protection Agency and PW-specific fractionation schemes. Factors influencing PW TIEs were investigated, such as the effect of salinity in selecting fractionation manipulations, the effect of toxicity test replication (i.e., reproducibility) in distinguishing changes in toxicities between whole PW and its fractions, and the suitability of different test species in PW TIEs. The results obtained and lessons learned from conducting these PW TIEs are presented in this article. Components, or fractions, contributing to toxicity differed for each PW with no specific fraction being consistently toxic. For most PW samples, toxicity attributed to any one fraction represented only part of the toxicity of the whole sample. However, no more than two fraction types were identified as potential toxicants in any sample. Potential toxicants identified during this study, besides salinity, included acidic and basic organic compound class fractions, particulates removed by filtration at pH 11, ammonia, hydrocarbons, hydrogen sulfide, material removed by pH change, and volatile compounds

  20. Arterial and venous plasma levels of bupivacaine following epidural and intercostal nerve blocks.

    Science.gov (United States)

    Moore, D C; Mather, L E; Bridenbaugh, P O; Bridenbaugh, L D; Balfour, R I; Lysons, D F; Horton, W G

    1976-07-01

    Arterial and peripheral venous plasma levels of bupivacaine were determined in 30 patients following epidural anesthesia using 150 and 225 mg, as well as following intercostal nerve block with 400 mg. Arterial levels were consistently higher than levels in simultaneously sampled venous blood, and the highest levels occurred with bilateral intercostal nerve block. No evidence of systemic toxicity was observed. The results suggest that bupivacaine may have a wider margin of safety in man than is now stated.

  1. Risking Aggression: Reply to Block

    Directory of Open Access Journals (Sweden)

    Kris Borer

    2010-05-01

    Full Text Available In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

  2. Risking Aggression: Reply to Block

    OpenAIRE

    Kris Borer

    2010-01-01

    In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

  3. A Novel Tetrathiafulvalene Building Block

    DEFF Research Database (Denmark)

    Jeppesen, Jan Oskar; Takimiya, Kazuo; Thorup, Niels

    1999-01-01

    Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported.......Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported....

  4. Biological indicators of cadmium exposure and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, Z A; Smith, L M

    1986-01-01

    The increasing environmental and occupational exposure of populations to cadmium creates the need for biological indicators of cadmium exposure and toxicity. The advantages and disadvantages of monitoring blood cadmium, urinary, fecal, hair, and tissue cadmium, serum creatine, beta 2-microglobulin, alpha 1-anti-trypsin and other proteins, and urinary amino acids, enzymes, total proteins, glucose, beta 2-microglobulin, retinol-binding protein, lysozyme, and metallothionein are discussed. It is concluded that urinary cadmium, metallothionein and beta 2-microglubulin may be used together to assess cadmium exposure and toxicity. 66 references.

  5. Skewed riskscapes and gentrified inequities: environmental exposure disparities in Seattle, Washington.

    Science.gov (United States)

    Abel, Troy D; White, Jonah

    2011-12-01

    Few studies have considered the sociohistorical intersection of environmental injustice and gentrification; a gap addressed by this case study of Seattle, Washington. This study explored the advantages of integrating air toxic risk screening with gentrification research to enhance proximity and health equity analysis methodologies. It was hypothesized that Seattle's industrial air toxic exposure risk was unevenly dispersed, that gentrification stratified the city's neighborhoods, and that the inequities of both converged. Spatial characterizations of air toxic pollution risk exposures from 1990 to 2007 were combined with longitudinal cluster analysis of census block groups in Seattle, Washington, from 1990 to 2000. A cluster of air toxic exposure inequality and socioeconomic inequity converged in 1 area of south central Seattle. Minority and working class residents were more concentrated in the same neighborhoods near Seattle's worst industrial pollution risks. Not all pollution was distributed equally in a dynamic urban landscape. Using techniques to examine skewed riskscapes and socioeconomic urban geographies provided a foundation for future research on the connections among environmental health hazard sources, socially vulnerable neighborhoods, and health inequity.

  6. Pediatric Toxic Shock Syndrome

    Directory of Open Access Journals (Sweden)

    Jennifer Yee

    2017-09-01

    Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

  7. Electronic Cigarette Toxicity.

    Science.gov (United States)

    Payne, J Drew; Michaels, David; Orellana-Barrios, Menfil; Nugent, Kenneth

    2017-04-01

    Electronic cigarettes (e-cigarettes) are often advertised as a healthier product when compared with traditional cigarettes. Currently, there are limited data to support this and only a threat of federal regulation from the US Food and Drug Administration. Calls to poison control centers about e-cigarette toxicity, especially in children, and case reports of toxic exposures have increased over the past 3 years. This research letter reports the frequency of hazardous exposures to e-cigarettes and characterizes the reported adverse health effects associated with e-cigarette toxicity.

  8. Toxicity Estimation Software Tool (TEST)

    Science.gov (United States)

    The Toxicity Estimation Software Tool (TEST) was developed to allow users to easily estimate the toxicity of chemicals using Quantitative Structure Activity Relationships (QSARs) methodologies. QSARs are mathematical models used to predict measures of toxicity from the physical c...

  9. FY 1999 cooperation program - Comprehensive research cooperation in environmental technology. Research cooperation in toxic/hazardous waste management in the Laguna de Bay region; 1999 nendo kenkyu kyoryoku jigyo. Kankyo gijutsu sogo kenkyu kyoryoku - Raguna ko chiiki ni okeru yudoku yugai haikibutsu ni kansuru kenkyu kyoryoku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    For the purpose of establishing preventive measures for water contamination in the Laguna de Bay region, the Philippines, where the water contamination is in progress and the eutrophication is feared, a research cooperation project was carried out on the water quality contamination monitoring technology (measuring method/analysis method/prediction method). In the survey of the state of generation of toxic/hazardous waste, the following were grasped based on the existing data: amount of use of toxic/hazardous substances in factories, state of generation of waste, situation of the processing/disposal, etc. In the detailed survey of the situation of pollution in the Laguna de Bay region, specimens of water quality and bottom material were collected from the lake and rivers thereinto, and qualitative/quantitative analysis of contaminants was made using atomic absorption spectrophotometer and gaschromatograph mass spectrometer. As to the evaluation of pollutant sources and control method, the paper conducted the introduction of measures generally taken against pollutant sources, study of a method to grasp the behavior of contaminants by the environmental assessment method for the closed water area, etc. The training was also conducted for researchers/engineers widely in charge of management of toxic/hazardous waste in the Philippines. (NEDO)

  10. Comparative study between ultrasound guided TAP block and paravertebral block in upper abdominal surgeries

    Directory of Open Access Journals (Sweden)

    Ruqaya M Elsayed Goda

    2017-01-01

    Conclusion: We concluded that ultrasound guided transverses abdominis plane block and thoracic paravertebral block were safe and effective anesthetic technique for upper abdominal surgery with longer and potent postoperative analgesia in thoracic paravertebral block than transverses abdominis block.

  11. Radiation treatment of toxic chemicals

    International Nuclear Information System (INIS)

    Lee, M.J.; Jung, I.H.; Jo, S.K.

    2010-01-01

    Polychlorinated biphenyls (PCBs) were commercially produced from 1920s as complex mixtures containing multiple isomers for a variety of applications. They are very toxic, chemically stable and resist microbial, photochemical, chemical, and thermal degradation. The public, legal, and scientific concerns about PCBs arose from research indicating they were environmental contaminants that had a potential to adversely impact the environment, and, therefore, were undesirable as commercial products. Eventually, most producers reduced or stopped production of PCBs in the 1970s. Stockholm convention on POPs (Persistent Organic Pollutants), which was effective on May 2004 and 151 nations including Korea were joined on June 2005, asked to dispose of PCBs by 2028 with environmental friendly methods. Korean government also has declared to conduct by 2015. According to the Environmental law of Korea, over 2 ppm of PCBs has to be decomposed by legal methods of incineration and thermal destruction. But those are inapplicable owing to the environmental groups. KAERI(Korea Atomic Energy Research Institute) has recently developed a remarkable technology for radiation treatment of toxic chemicals including chlorides using an electron beam accelerator. Electron beam accelerator of 2.5 MeV energy and 100 kW power capacity was used to decompose of PCBs having been used as a commercial transformer oil for more than 30 years. The oil were irradiated with ∼ 0.1 percent of TEA (Triethyl Amin) to make chloride ion aparted off from the PCBs into precipitate at the conditions of normal temperature and pressure. The concentrations of PCBs were measured by GC (Gas Chromatography) with ECD (Electron Capture Detector) following the KS (Korean Standard) test procedure. Electron beam should be a useful tool for environmental conservation. Residual concentrations of PCBs after irradiation were depended on the absorption dose of electron beam energy. Advantages comparing to other methods such as

  12. 40 CFR 80.1015 - Who is liable for violations under the gasoline toxics program?

    Science.gov (United States)

    2010-07-01

    ... gasoline toxics program? 80.1015 Section 80.1015 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Violation Provisions § 80.1015 Who is liable for violations under the gasoline toxics program? (a) Persons liable for...

  13. 40 CFR 80.1005 - What acts are prohibited under the gasoline toxics program?

    Science.gov (United States)

    2010-07-01

    ... gasoline toxics program? 80.1005 Section 80.1005 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Violation Provisions § 80.1005 What acts are prohibited under the gasoline toxics program? No person shall: (a...

  14. 40 CFR 80.810 - Who shall register with EPA under the gasoline toxics program?

    Science.gov (United States)

    2010-07-01

    ... gasoline toxics program? 80.810 Section 80.810 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics General Information § 80.810 Who shall register with EPA under the gasoline toxics program? (a) Refiners and importers...

  15. 40 CFR 80.910 - How does a refiner or importer apply for a toxics baseline?

    Science.gov (United States)

    2010-07-01

    ... for a toxics baseline? 80.910 Section 80.910 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Toxics Baseline Determination § 80.910 How does a refiner or importer apply for a toxics baseline? (a)(1) A refiner or importer...

  16. Various semiclassical limits of torus conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Alkalaev, Konstantin [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of General and Applied Physics, Moscow Institute of Physics and Technology,Institutskiy per. 7, Dolgoprudnyi, Moscow region, 141700 (Russian Federation); Geiko, Roman [Mathematics Department, National Research University Higher School of Economics,Usacheva str. 6, Moscow, 119048 (Russian Federation); Rappoport, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, Moscow, 127994 (Russian Federation)

    2017-04-12

    We study four types of one-point torus blocks arising in the large central charge regime. There are the global block, the light block, the heavy-light block, and the linearized classical block, according to different regimes of conformal dimensions. It is shown that the blocks are not independent being connected to each other by various links. We find that the global, light, and heavy-light blocks correspond to three different contractions of the Virasoro algebra. Also, we formulate the c-recursive representation of the one-point torus blocks which is relevant in the semiclassical approximation.

  17. Toxicity of clay flocculation of the toxic dinoflagellate, Karenia brevis, to estuarine invertebrates and fish

    Science.gov (United States)

    The benthic environmental effects of proposed control procedures for red tide events are relatively unknown but important to understand. The objective of this study was to determine the laboratory-derived toxicities of a clay flocculation technique proposed for the Florida red ti...

  18. Mixture toxicity of PBT-like chemicals

    DEFF Research Database (Denmark)

    Syberg, Kristian; Dai, Lina; Ramskov, Tina

    addition is a suitable model for default estimations of mixture effects. One of the major challenges is therefore how to select specific chemicals for actual mixture toxicity assessments. Persistant chemicals are likely to be present in the environment for an extended period of time, thus increasing...... the likelihood of them being present in environmentally found mixtures. Persistant, bioaccumulative and toxic (PBT) chemicals are therefore a highly relevant group of chemicals to consider for mixture toxicity regulation. The present study evaluates to what extent a number of PBT-like chemicals posess concern...... beyond that of the individual components. Firstly, the effects of three chemicals with PBT-like properties (acetyl cedrene, pyrene and triclosan) was examined on the freshwater snail, Potamopyrgus antipodarum. Secondly, mixture bioaccumulation of the same three chemicals were assessed experimentally...

  19. Hazardous and toxic waste management in Botswana: practices and challenges.

    Science.gov (United States)

    Mmereki, Daniel; Li, Baizhan; Meng, Liu

    2014-12-01

    Hazardous and toxic waste is a complex waste category because of its inherent chemical and physical characteristics. It demands for environmentally sound technologies and know-how as well as clean technologies that simultaneously manage and dispose it in an environmentally friendly way. Nevertheless, Botswana lacks a system covering all the critical steps from importation to final disposal or processing of hazardous and toxic waste owing to limited follow-up of the sources and types of hazardous and toxic waste, lack of modern and specialised treatment/disposal facilities, technical know-how, technically skilled manpower, funds and capabilities of local institutions to take lead in waste management. Therefore, because of a lack of an integrated system, there are challenges such as lack of cooperation among all the stakeholders about the safe management of hazardous and toxic waste. Furthermore, Botswana does not have a systematic regulatory framework regarding monitoring and hazardous and toxic waste management. In addition to the absence of a systematic regulatory framework, inadequate public awareness and dissemination of information about hazardous and toxic waste management, slower progress to phase-out persistent and bio-accumulative waste, and lack of reliable and accurate information on hazardous and toxic waste generation, sources and composition have caused critical challenges to effective hazardous and toxic waste management. It is, therefore, important to examine the status of hazardous and toxic waste as a waste stream in Botswana. By default; this mini-review article presents an overview of the current status of hazardous and toxic waste management and introduces the main challenges in hazardous and toxic waste management. Moreover, the article proposes the best applicable strategies to achieve effective hazardous and toxic waste management in the future. © The Author(s) 2014.

  20. Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

    Science.gov (United States)

    Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses a...